Merge branch 'develop'

.github/workflows/check.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: subosito/flutter-action@v1
         with:
           channel: stable
-          flutter-version: '1.22.3'
+          flutter-version: '1.22.4'
 
       - name: Clone the repository.
         uses: actions/checkout@v2

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
       - uses: subosito/flutter-action@v1
         with:
           channel: stable
-          flutter-version: '1.22.3'
+          flutter-version: '1.22.4'
 
       # Workaround for this Android Gradle Plugin issue (supposedly fixed in AGP 4.1):
       # https://issuetracker.google.com/issues/144111441
@@ -50,8 +50,8 @@ jobs:
           echo "${{ secrets.KEY_JKS }}" > release.keystore.asc
           gpg -d --passphrase "${{ secrets.KEY_JKS_PASSPHRASE }}" --batch release.keystore.asc > $AVES_STORE_FILE
           rm release.keystore.asc
-          flutter build apk --bundle-sksl-path shaders_1.22.3.sksl.json
+          flutter build apk --bundle-sksl-path shaders_1.22.4.sksl.json
-          flutter build appbundle --bundle-sksl-path shaders_1.22.3.sksl.json
+          flutter build appbundle --bundle-sksl-path shaders_1.22.4.sksl.json
           rm $AVES_STORE_FILE
         env:
           AVES_STORE_FILE: ${{ github.workspace }}/key.jks

CHANGELOG.md

@@ -0,0 +1,41 @@
+# Changelog
+All notable changes to this project will be documented in this file.
+
+## [Unreleased]
+
+## [v1.2.6] - 2020-11-15
+### Added
+- Support for TIFF images (single page)
+- Viewer overlay: minimap (optional)
+
+### Changed
+- Upgraded Flutter to stable v1.22.4
+- Viewer: use subsampling and tiling to display large images
+
+### Fixed
+- Fixed finding dimensions of entries with incorrect EXIF
+
+## [v1.2.5] - 2020-11-01
+### Added
+- Search: show recently used filters (optional)
+- Search: show filter for entries with no XMP tags
+- Search: show filter for entries with no location information
+- Analytics: use Firebase Analytics (along Firebase Crashlytics)
+
+### Changed
+- Upgraded Flutter to stable v1.22.3
+- Viewer overlay: showing shooting details is now optional
+
+### Fixed
+- Viewer: leave when the loaded entry is deleted and it is the last one
+- Viewer: refresh the viewer overlay and info page when the loaded image is modified
+- Info: prevent reporting a "Media" section for images other than HEIC/HEIF
+- Fixed opening entries shared via a "file" media content URI
+
+### Removed
+- Dependencies: removed Guava as a direct dependency in Android
+
+## [v1.2.4] - 2020-11-01 [YANKED]
+
+## [v1.2.3] - 2020-10-22
+...

android/app/build.gradle

@@ -88,9 +88,8 @@ flutter {
 }
 
 repositories {
-    maven {
+    maven { url 'https://jitpack.io' }
-        url "https://s3.amazonaws.com/repo.commonsware.com"
+    maven { url "https://s3.amazonaws.com/repo.commonsware.com" }
-    }
 }
 
 dependencies {
@@ -99,6 +98,11 @@ dependencies {
     implementation 'androidx.exifinterface:exifinterface:1.3.1'
     implementation 'com.commonsware.cwac:document:0.4.1'
     implementation 'com.drewnoakes:metadata-extractor:2.15.0'
+    // as of v0.9.8.7, `Android-TiffBitmapFactory` master branch is set up to release and distribute via Bintray
+    // as of 20201113, its `q_support` branch allows decoding TIFF without a `File`, but is not released
+    // we forked it to bypass official releases, upgrading its Android/Gradle structure to make it compatible with JitPack
+    // JitPack build result is available at https://jitpack.io/com/github/deckerst/Android-TiffBitmapFactory/<commit>/build.log
+    implementation 'com.github.deckerst:Android-TiffBitmapFactory:7efb450636'
     implementation 'com.github.bumptech.glide:glide:4.11.0'
 
     kapt 'androidx.annotation:annotation:1.1.0'

android/app/src/main/AndroidManifest.xml

@@ -45,7 +45,6 @@
     </queries>
 
     <application
-        android:name="io.flutter.app.FlutterApplication"
         android:icon="@mipmap/ic_launcher"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:label="@string/app_name"
@@ -55,11 +54,16 @@
             android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
             android:hardwareAccelerated="true"
             android:launchMode="singleTop"
-            android:theme="@style/AppTheme"
+            android:theme="@style/NormalTheme"
             android:windowSoftInputMode="adjustResize">
+            <!-- Specifies an Android theme to apply to this Activity as soon as
+                 the Android process has started. This theme is visible to the user
+                 while the Flutter UI initializes. After that, this theme continues
+                 to determine the Window background behind the Flutter UI. -->
             <meta-data
-                android:name="io.flutter.app.android.SplashScreenUntilFirstFrame"
+                android:name="io.flutter.embedding.android.NormalTheme"
-                android:value="false" />
+                android:resource="@style/NormalTheme"
+                />
 
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -105,11 +109,11 @@
         <meta-data
             android:name="com.google.android.geo.API_KEY"
             android:value="${googleApiKey}" />
-        <!-- Don't delete the meta-data below.
-             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
         <meta-data
             android:name="firebase_crashlytics_collection_enabled"
             android:value="false" />
+        <!-- Don't delete the meta-data below.
+             This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/AppAdapterHandler.kt

@@ -6,20 +6,19 @@ import android.content.Intent
 import android.content.pm.ApplicationInfo
 import android.content.pm.PackageManager
 import android.content.res.Configuration
-import android.graphics.Bitmap
 import android.net.Uri
 import android.util.Log
 import androidx.core.content.FileProvider
 import com.bumptech.glide.Glide
 import com.bumptech.glide.load.DecodeFormat
 import com.bumptech.glide.request.RequestOptions
+import deckers.thibault.aves.utils.BitmapUtils.getBytes
 import deckers.thibault.aves.utils.LogUtils.createTag
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
-import java.io.ByteArrayOutputStream
 import java.io.File
 import java.util.*
 import kotlin.collections.ArrayList
@@ -134,12 +133,7 @@ class AppAdapterHandler(private val context: Context) : MethodCallHandler {
                 .submit(size, size)
 
             try {
-                val bitmap = target.get()
+                data = target.get()?.getBytes(canHaveAlpha = true, recycle = false)
-                if (bitmap != null) {
-                    val stream = ByteArrayOutputStream()
-                    bitmap.compress(Bitmap.CompressFormat.PNG, 0, stream)
-                    data = stream.toByteArray()
-                }
             } catch (e: Exception) {
                 Log.w(LOG_TAG, "failed to decode app icon for packageName=$packageName", e)
             }

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/ImageFileHandler.kt

@@ -1,7 +1,9 @@
 package deckers.thibault.aves.channel.calls
 
 import android.app.Activity
+import android.graphics.Rect
 import android.net.Uri
+import android.util.Size
 import com.bumptech.glide.Glide
 import deckers.thibault.aves.model.ExifOrientationOp
 import deckers.thibault.aves.model.provider.FieldMap
@@ -19,11 +21,14 @@ import kotlin.math.roundToInt
 class ImageFileHandler(private val activity: Activity) : MethodCallHandler {
     private val density = activity.resources.displayMetrics.density
 
+    private val regionFetcher = RegionFetcher(activity)
+
     override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
         when (call.method) {
             "getObsoleteEntries" -> GlobalScope.launch { getObsoleteEntries(call, Coresult(result)) }
             "getImageEntry" -> GlobalScope.launch { getImageEntry(call, Coresult(result)) }
             "getThumbnail" -> GlobalScope.launch { getThumbnail(call, Coresult(result)) }
+            "getRegion" -> GlobalScope.launch { getRegion(call, Coresult(result)) }
             "clearSizedThumbnailDiskCache" -> {
                 GlobalScope.launch { Glide.get(activity).clearDiskCache() }
                 result.success(null)
@@ -53,26 +58,51 @@ class ImageFileHandler(private val activity: Activity) : MethodCallHandler {
         val widthDip = call.argument<Double>("widthDip")
         val heightDip = call.argument<Double>("heightDip")
         val defaultSizeDip = call.argument<Double>("defaultSizeDip")
+
         if (uri == null || mimeType == null || dateModifiedSecs == null || rotationDegrees == null || isFlipped == null || widthDip == null || heightDip == null || defaultSizeDip == null) {
             result.error("getThumbnail-args", "failed because of missing arguments", null)
             return
         }
 
         // convert DIP to physical pixels here, instead of using `devicePixelRatio` in Flutter
-        GlobalScope.launch {
+        ThumbnailFetcher(
-            ThumbnailFetcher(
+            activity,
-                activity,
+            uri,
-                uri,
+            mimeType,
-                mimeType,
+            dateModifiedSecs,
-                dateModifiedSecs,
+            rotationDegrees,
-                rotationDegrees,
+            isFlipped,
-                isFlipped,
+            width = (widthDip * density).roundToInt(),
-                width = (widthDip * density).roundToInt(),
+            height = (heightDip * density).roundToInt(),
-                height = (heightDip * density).roundToInt(),
+            defaultSize = (defaultSizeDip * density).roundToInt(),
-                defaultSize = (defaultSizeDip * density).roundToInt(),
+            result,
-                Coresult(result),
+        ).fetch()
-            ).fetch()
+    }
+
+    private fun getRegion(call: MethodCall, result: MethodChannel.Result) {
+        val uri = call.argument<String>("uri")?.let { Uri.parse(it) }
+        val mimeType = call.argument<String>("mimeType")
+        val sampleSize = call.argument<Int>("sampleSize")
+        val x = call.argument<Int>("regionX")
+        val y = call.argument<Int>("regionY")
+        val width = call.argument<Int>("regionWidth")
+        val height = call.argument<Int>("regionHeight")
+        val imageWidth = call.argument<Int>("imageWidth")
+        val imageHeight = call.argument<Int>("imageHeight")
+
+        if (uri == null || mimeType == null || sampleSize == null || x == null || y == null || width == null || height == null || imageWidth == null || imageHeight == null) {
+            result.error("getRegion-args", "failed because of missing arguments", null)
+            return
         }
+
+        regionFetcher.fetch(
+            uri,
+            mimeType,
+            sampleSize,
+            Rect(x, y, x + width, y + height),
+            Size(imageWidth, imageHeight),
+            result,
+        )
     }
 
     private suspend fun getImageEntry(call: MethodCall, result: MethodChannel.Result) {

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/MetadataHandler.kt

@@ -4,7 +4,7 @@ import android.content.ContentResolver
 import android.content.ContentUris
 import android.content.Context
 import android.database.Cursor
-import android.graphics.Bitmap
+import android.graphics.BitmapFactory
 import android.media.MediaMetadataRetriever
 import android.net.Uri
 import android.os.Build
@@ -28,7 +28,9 @@ import com.drew.metadata.xmp.XmpDirectory
 import deckers.thibault.aves.metadata.ExifInterfaceHelper
 import deckers.thibault.aves.metadata.ExifInterfaceHelper.describeAll
 import deckers.thibault.aves.metadata.ExifInterfaceHelper.getSafeDateMillis
+import deckers.thibault.aves.metadata.ExifInterfaceHelper.getSafeDouble
 import deckers.thibault.aves.metadata.ExifInterfaceHelper.getSafeInt
+import deckers.thibault.aves.metadata.ExifInterfaceHelper.getSafeRational
 import deckers.thibault.aves.metadata.MediaMetadataRetrieverHelper
 import deckers.thibault.aves.metadata.MediaMetadataRetrieverHelper.getSafeDateMillis
 import deckers.thibault.aves.metadata.MediaMetadataRetrieverHelper.getSafeDescription
@@ -38,26 +40,27 @@ import deckers.thibault.aves.metadata.Metadata.getRotationDegreesForExifCode
 import deckers.thibault.aves.metadata.Metadata.isFlippedForExifCode
 import deckers.thibault.aves.metadata.MetadataExtractorHelper.getSafeBoolean
 import deckers.thibault.aves.metadata.MetadataExtractorHelper.getSafeDateMillis
-import deckers.thibault.aves.metadata.MetadataExtractorHelper.getSafeDescription
 import deckers.thibault.aves.metadata.MetadataExtractorHelper.getSafeInt
 import deckers.thibault.aves.metadata.MetadataExtractorHelper.getSafeRational
 import deckers.thibault.aves.metadata.MetadataExtractorHelper.getSafeString
 import deckers.thibault.aves.metadata.XMP
 import deckers.thibault.aves.metadata.XMP.getSafeLocalizedText
 import deckers.thibault.aves.utils.BitmapUtils
+import deckers.thibault.aves.utils.BitmapUtils.getBytes
 import deckers.thibault.aves.utils.LogUtils
 import deckers.thibault.aves.utils.MimeTypes
 import deckers.thibault.aves.utils.MimeTypes.isImage
 import deckers.thibault.aves.utils.MimeTypes.isMultimedia
 import deckers.thibault.aves.utils.MimeTypes.isSupportedByMetadataExtractor
 import deckers.thibault.aves.utils.MimeTypes.isVideo
+import deckers.thibault.aves.utils.MimeTypes.tiffExtensionPattern
 import deckers.thibault.aves.utils.StorageUtils
 import io.flutter.plugin.common.MethodCall
 import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
-import java.io.ByteArrayOutputStream
+import java.io.IOException
 import java.util.*
 import kotlin.math.roundToLong
 
@@ -70,6 +73,8 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
             "getContentResolverMetadata" -> GlobalScope.launch { getContentResolverMetadata(call, Coresult(result)) }
             "getExifInterfaceMetadata" -> GlobalScope.launch { getExifInterfaceMetadata(call, Coresult(result)) }
             "getMediaMetadataRetrieverMetadata" -> GlobalScope.launch { getMediaMetadataRetrieverMetadata(call, Coresult(result)) }
+            "getBitmapFactoryInfo" -> GlobalScope.launch { getBitmapFactoryInfo(call, Coresult(result)) }
+            "getMetadataExtractorSummary" -> GlobalScope.launch { getMetadataExtractorSummary(call, Coresult(result)) }
             "getEmbeddedPictures" -> GlobalScope.launch { getEmbeddedPictures(call, Coresult(result)) }
             "getExifThumbnails" -> GlobalScope.launch { getExifThumbnails(call, Coresult(result)) }
             "getXmpThumbnails" -> GlobalScope.launch { getXmpThumbnails(call, Coresult(result)) }
@@ -182,12 +187,13 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
     private fun getCatalogMetadata(call: MethodCall, result: MethodChannel.Result) {
         val mimeType = call.argument<String>("mimeType")
         val uri = call.argument<String>("uri")?.let { Uri.parse(it) }
+        val path = call.argument<String>("path")
         if (mimeType == null || uri == null) {
             result.error("getCatalogMetadata-args", "failed because of missing arguments", null)
             return
         }
 
-        val metadataMap = HashMap(getCatalogMetadataByMetadataExtractor(uri, mimeType))
+        val metadataMap = HashMap(getCatalogMetadataByMetadataExtractor(uri, mimeType, path))
         if (isVideo(mimeType)) {
             metadataMap.putAll(getVideoCatalogMetadataByMediaMetadataRetriever(uri))
         }
@@ -196,7 +202,7 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
         result.success(metadataMap)
     }
 
-    private fun getCatalogMetadataByMetadataExtractor(uri: Uri, mimeType: String): Map<String, Any> {
+    private fun getCatalogMetadataByMetadataExtractor(uri: Uri, mimeType: String, path: String?): Map<String, Any> {
         val metadataMap = HashMap<String, Any>()
 
         var foundExif = false
@@ -209,14 +215,17 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
 
                     // File type
                     for (dir in metadata.getDirectoriesOfType(FileTypeDirectory::class.java)) {
-                        // `metadata-extractor` sometimes detect the the wrong mime type (e.g. `pef` file as `tiff`)
+                        // * `metadata-extractor` sometimes detect the the wrong mime type (e.g. `pef` file as `tiff`)
-                        // the content resolver / media store sometimes report the wrong mime type (e.g. `png` file as `jpeg`)
+                        // * the content resolver / media store sometimes report the wrong mime type (e.g. `png` file as `jpeg`, `tiff` as `srw`)
-                        // `context.getContentResolver().getType()` sometimes return incorrect value
+                        // * `context.getContentResolver().getType()` sometimes return incorrect value
-                        // `MediaMetadataRetriever.setDataSource()` sometimes fail with `status = 0x80000000`
+                        // * `MediaMetadataRetriever.setDataSource()` sometimes fail with `status = 0x80000000`
-                        // file extension is unreliable
+                        // * file extension is unreliable
-                        // in the end, `metadata-extractor` is the most reliable, unless it reports `tiff`
+                        // In the end, `metadata-extractor` is the most reliable, except for `tiff` (false positives, false negatives),
-                        dir.getSafeString(FileTypeDirectory.TAG_DETECTED_FILE_MIME_TYPE) {
+                        // in which case we trust the file extension
-                            if (it != MimeTypes.TIFF) {
+                        if (path?.matches(tiffExtensionPattern) == true) {
+                            metadataMap[KEY_MIME_TYPE] = MimeTypes.TIFF
+                        } else {
+                            dir.getSafeString(FileTypeDirectory.TAG_DETECTED_FILE_MIME_TYPE) {
                                 metadataMap[KEY_MIME_TYPE] = it
                             }
                         }
@@ -351,37 +360,62 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
         }
 
         val metadataMap = HashMap<String, Any>()
-        if (isVideo(mimeType) || !isSupportedByMetadataExtractor(mimeType)) {
+        if (isVideo(mimeType)) {
             result.success(metadataMap)
             return
         }
-        try {
+
-            StorageUtils.openInputStream(context, uri)?.use { input ->
+        val saveExposureTime: (value: Rational) -> Unit = {
-                val metadata = ImageMetadataReader.readMetadata(input)
+            // `TAG_EXPOSURE_TIME` as a string is sometimes a ratio, sometimes a decimal
-                for (dir in metadata.getDirectoriesOfType(ExifSubIFDDirectory::class.java)) {
+            // so we explicitly request it as a rational (e.g. 1/100, 1/14, 71428571/1000000000, 4000/1000, 2000000000/500000000)
-                    dir.getSafeDescription(ExifSubIFDDirectory.TAG_FNUMBER) { metadataMap[KEY_APERTURE] = it }
+            // and process it to make sure the numerator is `1` when the ratio value is less than 1
-                    dir.getSafeDescription(ExifSubIFDDirectory.TAG_FOCAL_LENGTH) { metadataMap[KEY_FOCAL_LENGTH] = it }
+            val num = it.numerator
-                    dir.getSafeDescription(ExifSubIFDDirectory.TAG_ISO_EQUIVALENT) { metadataMap[KEY_ISO] = "ISO$it" }
+            val denom = it.denominator
-                    dir.getSafeRational(ExifSubIFDDirectory.TAG_EXPOSURE_TIME) {
+            metadataMap[KEY_EXPOSURE_TIME] = when {
-                        // TAG_EXPOSURE_TIME as a string is sometimes a ratio, sometimes a decimal
+                num >= denom -> "${it.toSimpleString(true)}″"
-                        // so we explicitly request it as a rational (e.g. 1/100, 1/14, 71428571/1000000000, 4000/1000, 2000000000/500000000)
+                num != 1L && num != 0L -> Rational(1, (denom / num.toDouble()).roundToLong()).toString()
-                        // and process it to make sure the numerator is `1` when the ratio value is less than 1
+                else -> it.toString()
-                        val num = it.numerator
+            }
-                        val denom = it.denominator
+        }
-                        metadataMap[KEY_EXPOSURE_TIME] = when {
+
-                            num >= denom -> "${it.toSimpleString(true)}″"
+        var foundExif = false
-                            num != 1L && num != 0L -> Rational(1, (denom / num.toDouble()).roundToLong()).toString()
+        if (isSupportedByMetadataExtractor(mimeType)) {
-                            else -> it.toString()
+            try {
-                        }
+                StorageUtils.openInputStream(context, uri)?.use { input ->
+                    val metadata = ImageMetadataReader.readMetadata(input)
+                    for (dir in metadata.getDirectoriesOfType(ExifSubIFDDirectory::class.java)) {
+                        foundExif = true
+                        dir.getSafeRational(ExifSubIFDDirectory.TAG_FNUMBER) { metadataMap[KEY_APERTURE] = it.numerator.toDouble() / it.denominator }
+                        dir.getSafeRational(ExifSubIFDDirectory.TAG_EXPOSURE_TIME, saveExposureTime)
+                        dir.getSafeRational(ExifSubIFDDirectory.TAG_FOCAL_LENGTH) { metadataMap[KEY_FOCAL_LENGTH] = it.numerator.toDouble() / it.denominator }
+                        dir.getSafeInt(ExifSubIFDDirectory.TAG_ISO_EQUIVALENT) { metadataMap[KEY_ISO] = it }
                     }
                 }
-                result.success(metadataMap)
+            } catch (e: Exception) {
-            } ?: result.error("getOverlayMetadata-noinput", "failed to get metadata for uri=$uri", null)
+                Log.w(LOG_TAG, "failed to get metadata by metadata-extractor for uri=$uri", e)
-        } catch (e: Exception) {
+            } catch (e: NoClassDefFoundError) {
-            result.error("getOverlayMetadata-exception", "failed to get metadata for uri=$uri", e.message)
+                Log.w(LOG_TAG, "failed to get metadata by metadata-extractor for uri=$uri", e)
-        } catch (e: NoClassDefFoundError) {
+            }
-            result.error("getOverlayMetadata-exception", "failed to get metadata for uri=$uri", e.message)
         }
+
+        if (!foundExif) {
+            // fallback to read EXIF via ExifInterface
+            try {
+                StorageUtils.openInputStream(context, uri)?.use { input ->
+                    val exif = ExifInterface(input)
+                    exif.getSafeDouble(ExifInterface.TAG_F_NUMBER) { metadataMap[KEY_APERTURE] = it }
+                    exif.getSafeRational(ExifInterface.TAG_EXPOSURE_TIME, saveExposureTime)
+                    exif.getSafeDouble(ExifInterface.TAG_FOCAL_LENGTH) { metadataMap[KEY_FOCAL_LENGTH] = it }
+                    exif.getSafeInt(ExifInterface.TAG_PHOTOGRAPHIC_SENSITIVITY) { metadataMap[KEY_ISO] = it }
+                }
+            } catch (e: Exception) {
+                // ExifInterface initialization can fail with a RuntimeException
+                // caused by an internal MediaMetadataRetriever failure
+                Log.w(LOG_TAG, "failed to get metadata by ExifInterface for uri=$uri", e)
+            }
+        }
+
+        result.success(metadataMap)
     }
 
     private fun getContentResolverMetadata(call: MethodCall, result: MethodChannel.Result) {
@@ -483,6 +517,77 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
         result.success(metadataMap)
     }
 
+    private fun getBitmapFactoryInfo(call: MethodCall, result: MethodChannel.Result) {
+        val uri = call.argument<String>("uri")?.let { Uri.parse(it) }
+        if (uri == null) {
+            result.error("getBitmapDecoderInfo-args", "failed because of missing arguments", null)
+            return
+        }
+
+        val metadataMap = HashMap<String, String>()
+        try {
+            StorageUtils.openInputStream(context, uri)?.use { input ->
+                val options = BitmapFactory.Options().apply {
+                    inJustDecodeBounds = true
+                }
+                BitmapFactory.decodeStream(input, null, options)
+                options.outMimeType?.let { metadataMap["MimeType"] = it }
+                options.outWidth.takeIf { it >= 0 }?.let { metadataMap["Width"] = it.toString() }
+                options.outHeight.takeIf { it >= 0 }?.let { metadataMap["Height"] = it.toString() }
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                    options.outColorSpace?.let { metadataMap["ColorSpace"] = it.toString() }
+                    options.outConfig?.let { metadataMap["Config"] = it.toString() }
+                }
+            }
+        } catch (e: IOException) {
+            // ignore
+        }
+        result.success(metadataMap)
+    }
+
+    private fun getMetadataExtractorSummary(call: MethodCall, result: MethodChannel.Result) {
+        val uri = call.argument<String>("uri")?.let { Uri.parse(it) }
+        if (uri == null) {
+            result.error("getMetadataExtractorSummary-args", "failed because of missing arguments", null)
+            return
+        }
+
+        val metadataMap = HashMap<String, String>()
+        try {
+            StorageUtils.openInputStream(context, uri)?.use { input ->
+                val metadata = ImageMetadataReader.readMetadata(input)
+                metadataMap["mimeType"] = metadata.getDirectoriesOfType(FileTypeDirectory::class.java).joinToString { dir ->
+                    if (dir.containsTag(FileTypeDirectory.TAG_DETECTED_FILE_MIME_TYPE)) {
+                        dir.getString(FileTypeDirectory.TAG_DETECTED_FILE_MIME_TYPE)
+                    } else ""
+                }
+                metadataMap["typeName"] = metadata.getDirectoriesOfType(FileTypeDirectory::class.java).joinToString { dir ->
+                    if (dir.containsTag(FileTypeDirectory.TAG_DETECTED_FILE_TYPE_NAME)) {
+                        dir.getString(FileTypeDirectory.TAG_DETECTED_FILE_TYPE_NAME)
+                    } else ""
+                }
+                for (dir in metadata.directories) {
+                    val dirName = dir.name ?: ""
+                    var index = 0
+                    while (metadataMap.containsKey("$dirName ($index)")) index++
+                    var value = "${dir.tagCount} tags"
+                    dir.parent?.let { value += ", parent: ${it.name}" }
+                    metadataMap["$dirName ($index)"] = value
+                }
+            }
+        } catch (e: Exception) {
+            Log.w(LOG_TAG, "failed to get metadata by metadata-extractor for uri=$uri", e)
+        } catch (e: NoClassDefFoundError) {
+            Log.w(LOG_TAG, "failed to get metadata by metadata-extractor for uri=$uri", e)
+        }
+
+        if (metadataMap.isNotEmpty()) {
+            result.success(metadataMap)
+        } else {
+            result.error("getMetadataExtractorSummary-failure", "failed to get metadata for uri=$uri", null)
+        }
+    }
+
     private fun getEmbeddedPictures(call: MethodCall, result: MethodChannel.Result) {
         val uri = call.argument<String>("uri")?.let { Uri.parse(it) }
         if (uri == null) {
@@ -517,14 +622,9 @@ class MetadataHandler(private val context: Context) : MethodCallHandler {
             StorageUtils.openInputStream(context, uri)?.use { input ->
                 val exif = ExifInterface(input)
                 val orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL)
-                exif.thumbnailBitmap?.let {
+                exif.thumbnailBitmap?.let { bitmap ->
-                    val bitmap = TransformationUtils.rotateImageExif(BitmapUtils.getBitmapPool(context), it, orientation)
+                    TransformationUtils.rotateImageExif(BitmapUtils.getBitmapPool(context), bitmap, orientation)?.let {
-                    if (bitmap != null) {
+                        thumbnails.add(it.getBytes(canHaveAlpha = false, recycle = false))
-                        val stream = ByteArrayOutputStream()
-                        // we compress the bitmap because Dart Image.memory cannot decode the raw bytes
-                        // Bitmap.CompressFormat.PNG is slower than JPEG
-                        bitmap.compress(Bitmap.CompressFormat.JPEG, 90, stream)
-                        thumbnails.add(stream.toByteArray())
                     }
                 }
             }

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/RegionFetcher.kt

@@ -0,0 +1,82 @@
+package deckers.thibault.aves.channel.calls
+
+import android.content.Context
+import android.graphics.BitmapFactory
+import android.graphics.BitmapRegionDecoder
+import android.graphics.Rect
+import android.net.Uri
+import android.util.Size
+import deckers.thibault.aves.utils.BitmapUtils.getBytes
+import deckers.thibault.aves.utils.MimeTypes
+import deckers.thibault.aves.utils.StorageUtils
+import io.flutter.plugin.common.MethodChannel
+import kotlin.math.roundToInt
+
+class RegionFetcher internal constructor(
+    private val context: Context,
+) {
+    private var lastDecoderRef: LastDecoderRef? = null
+
+    fun fetch(
+        uri: Uri,
+        mimeType: String,
+        sampleSize: Int,
+        regionRect: Rect,
+        imageSize: Size,
+        result: MethodChannel.Result,
+    ) {
+        val options = BitmapFactory.Options().apply {
+            inSampleSize = sampleSize
+        }
+
+        var currentDecoderRef = lastDecoderRef
+        if (currentDecoderRef != null && currentDecoderRef.uri != uri) {
+            currentDecoderRef.decoder.recycle()
+            currentDecoderRef = null
+        }
+
+        try {
+            if (currentDecoderRef == null) {
+                val newDecoder = StorageUtils.openInputStream(context, uri)?.use { input ->
+                    BitmapRegionDecoder.newInstance(input, false)
+                }
+                if (newDecoder == null) {
+                    result.error("getRegion-read-null", "failed to open file for uri=$uri regionRect=$regionRect", null)
+                    return
+                }
+                currentDecoderRef = LastDecoderRef(uri, newDecoder)
+            }
+            val decoder = currentDecoderRef.decoder
+            lastDecoderRef = currentDecoderRef
+
+            // with raw images, the known image size may not match the decoded image size
+            // so we scale the requested region accordingly
+            val effectiveRect = if (imageSize.width != decoder.width || imageSize.height != decoder.height) {
+                val xf = decoder.width.toDouble() / imageSize.width
+                val yf = decoder.height.toDouble() / imageSize.height
+                Rect(
+                    (regionRect.left * xf).roundToInt(),
+                    (regionRect.top * yf).roundToInt(),
+                    (regionRect.right * xf).roundToInt(),
+                    (regionRect.bottom * yf).roundToInt(),
+                )
+            } else {
+                regionRect
+            }
+
+            val bitmap = decoder.decodeRegion(effectiveRect, options)
+            if (bitmap != null) {
+                result.success(bitmap.getBytes(MimeTypes.canHaveAlpha(mimeType), recycle = true))
+            } else {
+                result.error("getRegion-null", "failed to decode region for uri=$uri regionRect=$regionRect", null)
+            }
+        } catch (e: Exception) {
+            result.error("getRegion-read-exception", "failed to initialize region decoder for uri=$uri regionRect=$regionRect", e.message)
+        }
+    }
+}
+
+private data class LastDecoderRef(
+    val uri: Uri,
+    val decoder: BitmapRegionDecoder,
+)

android/app/src/main/kotlin/deckers/thibault/aves/channel/calls/ThumbnailFetcher.kt

@@ -1,7 +1,7 @@
 package deckers.thibault.aves.channel.calls
 
-import android.app.Activity
 import android.content.ContentUris
+import android.content.Context
 import android.graphics.Bitmap
 import android.net.Uri
 import android.os.Build
@@ -15,14 +15,16 @@ import com.bumptech.glide.request.RequestOptions
 import com.bumptech.glide.signature.ObjectKey
 import deckers.thibault.aves.decoder.VideoThumbnail
 import deckers.thibault.aves.utils.BitmapUtils.applyExifOrientation
+import deckers.thibault.aves.utils.BitmapUtils.getBytes
+import deckers.thibault.aves.utils.MimeTypes
 import deckers.thibault.aves.utils.MimeTypes.isVideo
 import deckers.thibault.aves.utils.MimeTypes.needRotationAfterContentResolverThumbnail
 import deckers.thibault.aves.utils.MimeTypes.needRotationAfterGlide
 import io.flutter.plugin.common.MethodChannel
-import java.io.ByteArrayOutputStream
+import org.beyka.tiffbitmapfactory.TiffBitmapFactory
 
 class ThumbnailFetcher internal constructor(
-    private val activity: Activity,
+    private val context: Context,
     uri: String,
     private val mimeType: String,
     private val dateModifiedSecs: Long,
@@ -39,59 +41,57 @@ class ThumbnailFetcher internal constructor(
 
     fun fetch() {
         var bitmap: Bitmap? = null
+        var recycle = true
         var exception: Exception? = null
 
-        // fetch low quality thumbnails when size is not specified
+        try {
-        if ((width == defaultSize || height == defaultSize) && !isFlipped) {
+            if (mimeType == MimeTypes.TIFF) {
-            // as of Android R, the Media Store content resolver may return a thumbnail
+                bitmap = getTiff()
-            // that is automatically rotated according to EXIF orientation,
+            } else if ((width == defaultSize || height == defaultSize) && !isFlipped) {
-            // but not flipped when necessary
+                // Fetch low quality thumbnails when size is not specified.
-            // so we skip this step for flipped entries
+                // As of Android R, the Media Store content resolver may return a thumbnail
-            try {
+                // that is automatically rotated according to EXIF orientation, but not flipped,
+                // so we skip this step for flipped entries.
                 bitmap = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) getByResolver() else getByMediaStore()
-            } catch (e: Exception) {
-                exception = e
             }
+        } catch (e: Exception) {
+            exception = e
         }
 
         // fallback if the native methods failed or for higher quality thumbnails
         if (bitmap == null) {
             try {
                 bitmap = getByGlide()
+                recycle = false
             } catch (e: Exception) {
                 exception = e
             }
         }
 
         if (bitmap != null) {
-            val stream = ByteArrayOutputStream()
+            result.success(bitmap.getBytes(MimeTypes.canHaveAlpha(mimeType), recycle = recycle))
-            // we compress the bitmap because Dart Image.memory cannot decode the raw bytes
+        } else {
-            // Bitmap.CompressFormat.PNG is slower than JPEG
+            var errorDetails: String? = exception?.message
-            bitmap.compress(Bitmap.CompressFormat.JPEG, 90, stream)
+            if (errorDetails?.isNotEmpty() == true) {
-            result.success(stream.toByteArray())
+                errorDetails = errorDetails.split("\n".toRegex(), 2).first()
-            return
+            }
+            result.error("getThumbnail-null", "failed to get thumbnail for uri=$uri", errorDetails)
         }
-
-        var errorDetails: String? = exception?.message
-        if (errorDetails?.isNotEmpty() == true) {
-            errorDetails = errorDetails.split("\n".toRegex(), 2).first()
-        }
-        result.error("getThumbnail-null", "failed to get thumbnail for uri=$uri", errorDetails)
     }
 
     @RequiresApi(api = Build.VERSION_CODES.Q)
     private fun getByResolver(): Bitmap? {
-        val resolver = activity.contentResolver
+        val resolver = context.contentResolver
         var bitmap: Bitmap? = resolver.loadThumbnail(uri, Size(width, height), null)
         if (needRotationAfterContentResolverThumbnail(mimeType)) {
-            bitmap = applyExifOrientation(activity, bitmap, rotationDegrees, isFlipped)
+            bitmap = applyExifOrientation(context, bitmap, rotationDegrees, isFlipped)
         }
         return bitmap
     }
 
     private fun getByMediaStore(): Bitmap? {
         val contentId = ContentUris.parseId(uri)
-        val resolver = activity.contentResolver
+        val resolver = context.contentResolver
         return if (isVideo(mimeType)) {
             @Suppress("DEPRECATION")
             MediaStore.Video.Thumbnails.getThumbnail(resolver, contentId, MediaStore.Video.Thumbnails.MINI_KIND, null)
@@ -100,7 +100,7 @@ class ThumbnailFetcher internal constructor(
             var bitmap = MediaStore.Images.Thumbnails.getThumbnail(resolver, contentId, MediaStore.Images.Thumbnails.MINI_KIND, null)
             // from Android Q, returned thumbnail is already rotated according to EXIF orientation
             if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q && bitmap != null) {
-                bitmap = applyExifOrientation(activity, bitmap, rotationDegrees, isFlipped)
+                bitmap = applyExifOrientation(context, bitmap, rotationDegrees, isFlipped)
             }
             bitmap
         }
@@ -115,13 +115,13 @@ class ThumbnailFetcher internal constructor(
 
         val target = if (isVideo(mimeType)) {
             options = options.diskCacheStrategy(DiskCacheStrategy.RESOURCE)
-            Glide.with(activity)
+            Glide.with(context)
                 .asBitmap()
                 .apply(options)
-                .load(VideoThumbnail(activity, uri))
+                .load(VideoThumbnail(context, uri))
                 .submit(width, height)
         } else {
-            Glide.with(activity)
+            Glide.with(context)
                 .asBitmap()
                 .apply(options)
                 .load(uri)
@@ -131,11 +131,38 @@ class ThumbnailFetcher internal constructor(
         return try {
             var bitmap = target.get()
             if (needRotationAfterGlide(mimeType)) {
-                bitmap = applyExifOrientation(activity, bitmap, rotationDegrees, isFlipped)
+                bitmap = applyExifOrientation(context, bitmap, rotationDegrees, isFlipped)
             }
             bitmap
         } finally {
-            Glide.with(activity).clear(target)
+            Glide.with(context).clear(target)
+        }
+    }
+
+    private fun getTiff(): Bitmap? {
+        // determine sample size
+        var sampleSize = 1
+        context.contentResolver.openFileDescriptor(uri, "r")?.use { descriptor ->
+            val options = TiffBitmapFactory.Options().apply {
+                inJustDecodeBounds = true
+            }
+            TiffBitmapFactory.decodeFileDescriptor(descriptor.fd, options)
+            val imageWidth = options.outWidth
+            val imageHeight = options.outHeight
+            if (imageHeight > height || imageWidth > width) {
+                while (imageHeight / (sampleSize * 2) > height && imageWidth / (sampleSize * 2) > width) {
+                    sampleSize *= 2
+                }
+            }
+        }
+
+        // decode
+        return context.contentResolver.openFileDescriptor(uri, "r")?.use { descriptor ->
+            val options = TiffBitmapFactory.Options().apply {
+                inJustDecodeBounds = false
+                inSampleSize = sampleSize
+            }
+            return TiffBitmapFactory.decodeFileDescriptor(descriptor.fd, options)
         }
     }
 }

android/app/src/main/kotlin/deckers/thibault/aves/channel/streams/ImageByteStreamHandler.kt

@@ -1,7 +1,6 @@
 package deckers.thibault.aves.channel.streams
 
 import android.app.Activity
-import android.graphics.Bitmap
 import android.net.Uri
 import android.os.Handler
 import android.os.Looper
@@ -11,16 +10,17 @@ import com.bumptech.glide.load.engine.DiskCacheStrategy
 import com.bumptech.glide.request.RequestOptions
 import deckers.thibault.aves.decoder.VideoThumbnail
 import deckers.thibault.aves.utils.BitmapUtils.applyExifOrientation
-import deckers.thibault.aves.utils.MimeTypes.canHaveAlpha
+import deckers.thibault.aves.utils.BitmapUtils.getBytes
+import deckers.thibault.aves.utils.MimeTypes
 import deckers.thibault.aves.utils.MimeTypes.isSupportedByFlutter
 import deckers.thibault.aves.utils.MimeTypes.isVideo
 import deckers.thibault.aves.utils.MimeTypes.needRotationAfterGlide
-import deckers.thibault.aves.utils.StorageUtils.openInputStream
+import deckers.thibault.aves.utils.StorageUtils
 import io.flutter.plugin.common.EventChannel
 import io.flutter.plugin.common.EventChannel.EventSink
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
-import java.io.ByteArrayOutputStream
+import org.beyka.tiffbitmapfactory.TiffBitmapFactory
 import java.io.IOException
 import java.io.InputStream
 
@@ -72,6 +72,8 @@ class ImageByteStreamHandler(private val activity: Activity, private val argumen
 
         if (isVideo(mimeType)) {
             streamVideoByGlide(uri)
+        } else if (mimeType == MimeTypes.TIFF) {
+            streamTiffImage(uri)
         } else if (!isSupportedByFlutter(mimeType, rotationDegrees, isFlipped)) {
             // decode exotic format on platform side, then encode it in portable format for Flutter
             streamImageByGlide(uri, mimeType, rotationDegrees, isFlipped)
@@ -84,7 +86,7 @@ class ImageByteStreamHandler(private val activity: Activity, private val argumen
 
     private fun streamImageAsIs(uri: Uri) {
         try {
-            openInputStream(activity, uri).use { input -> input?.let { streamBytes(it) } }
+            StorageUtils.openInputStream(activity, uri)?.use { input -> streamBytes(input) }
         } catch (e: IOException) {
             error("streamImage-image-read-exception", "failed to get image from uri=$uri", e.message)
         }
@@ -102,24 +104,12 @@ class ImageByteStreamHandler(private val activity: Activity, private val argumen
                 bitmap = applyExifOrientation(activity, bitmap, rotationDegrees, isFlipped)
             }
             if (bitmap != null) {
-                val stream = ByteArrayOutputStream()
+                success(bitmap.getBytes(MimeTypes.canHaveAlpha(mimeType), recycle = false))
-                // we compress the bitmap because Dart Image.memory cannot decode the raw bytes
-                // Bitmap.CompressFormat.PNG is slower than JPEG, but it allows transparency
-                if (canHaveAlpha(mimeType)) {
-                    bitmap.compress(Bitmap.CompressFormat.PNG, 0, stream)
-                } else {
-                    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream)
-                }
-                success(stream.toByteArray())
             } else {
                 error("streamImage-image-decode-null", "failed to get image from uri=$uri", null)
             }
         } catch (e: Exception) {
-            var errorDetails = e.message
+            error("streamImage-image-decode-exception", "failed to get image from uri=$uri", toErrorDetails(e))
-            if (errorDetails?.isNotEmpty() == true) {
-                errorDetails = errorDetails.split("\n".toRegex(), 2).first()
-            }
-            error("streamImage-image-decode-exception", "failed to get image from uri=$uri", errorDetails)
         } finally {
             Glide.with(activity).clear(target)
         }
@@ -134,11 +124,7 @@ class ImageByteStreamHandler(private val activity: Activity, private val argumen
         try {
             val bitmap = target.get()
             if (bitmap != null) {
-                val stream = ByteArrayOutputStream()
+                success(bitmap.getBytes(canHaveAlpha = false, recycle = false))
-                // we compress the bitmap because Dart Image.memory cannot decode the raw bytes
-                // Bitmap.CompressFormat.PNG is slower than JPEG
-                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, stream)
-                success(stream.toByteArray())
             } else {
                 error("streamImage-video-null", "failed to get image from uri=$uri", null)
             }
@@ -149,6 +135,48 @@ class ImageByteStreamHandler(private val activity: Activity, private val argumen
         }
     }
 
+    private fun streamTiffImage(uri: Uri) {
+        val resolver = activity.contentResolver
+        try {
+            var dirCount = 0
+            resolver.openFileDescriptor(uri, "r")?.use { descriptor ->
+                val options = TiffBitmapFactory.Options().apply {
+                    inJustDecodeBounds = true
+                }
+                TiffBitmapFactory.decodeFileDescriptor(descriptor.fd, options)
+                dirCount = options.outDirectoryCount
+            }
+
+            // TODO TLAD handle multipage TIFF
+            if (dirCount > 0) {
+                val i = 0
+                resolver.openFileDescriptor(uri, "r")?.use { descriptor ->
+                    val options = TiffBitmapFactory.Options().apply {
+                        inJustDecodeBounds = false
+                        inDirectoryNumber = i
+                    }
+                    val bitmap = TiffBitmapFactory.decodeFileDescriptor(descriptor.fd, options)
+                    if (bitmap != null) {
+                        success(bitmap.getBytes(canHaveAlpha = true, recycle = true))
+                    } else {
+                        error("streamImage-tiff-null", "failed to get tiff image (dir=$i) from uri=$uri", null)
+                    }
+                }
+            }
+        } catch (e: Exception) {
+            error("streamImage-tiff-exception", "failed to get image from uri=$uri", toErrorDetails(e))
+        }
+    }
+
+    private fun toErrorDetails(e: Exception): String? {
+        val errorDetails = e.message
+        return if (errorDetails?.isNotEmpty() == true) {
+            errorDetails.split("\n".toRegex(), 2).first()
+        } else {
+            errorDetails
+        }
+    }
+
     private fun streamBytes(inputStream: InputStream) {
         val buffer = ByteArray(bufferSize)
         var len: Int

android/app/src/main/kotlin/deckers/thibault/aves/decoder/VideoThumbnailGlideModule.kt

@@ -1,7 +1,6 @@
 package deckers.thibault.aves.decoder
 
 import android.content.Context
-import android.graphics.Bitmap
 import android.net.Uri
 import com.bumptech.glide.Glide
 import com.bumptech.glide.Priority
@@ -16,9 +15,9 @@ import com.bumptech.glide.load.model.ModelLoaderFactory
 import com.bumptech.glide.load.model.MultiModelLoaderFactory
 import com.bumptech.glide.module.LibraryGlideModule
 import com.bumptech.glide.signature.ObjectKey
+import deckers.thibault.aves.utils.BitmapUtils.getBytes
 import deckers.thibault.aves.utils.StorageUtils.openMetadataRetriever
 import java.io.ByteArrayInputStream
-import java.io.ByteArrayOutputStream
 import java.io.InputStream
 
 @GlideModule
@@ -49,16 +48,12 @@ internal class VideoThumbnailFetcher(private val model: VideoThumbnail) : DataFe
         val retriever = openMetadataRetriever(model.context, model.uri)
         if (retriever != null) {
             try {
-                var picture = retriever.embeddedPicture
+                val picture = retriever.embeddedPicture ?: retriever.frameAtTime?.getBytes(canHaveAlpha = false, recycle = false)
-                if (picture == null) {
+                if (picture != null) {
-                    // not ideal: bitmap -> byte[] -> bitmap
+                    callback.onDataReady(ByteArrayInputStream(picture))
-                    // but simple fallback and we cache result
+                } else {
-                    val stream = ByteArrayOutputStream()
+                    callback.onLoadFailed(Exception("failed to get embedded picture or any frame"))
-                    val bitmap = retriever.frameAtTime
-                    bitmap?.compress(Bitmap.CompressFormat.PNG, 0, stream)
-                    picture = stream.toByteArray()
                 }
-                callback.onDataReady(ByteArrayInputStream(picture))
             } catch (e: Exception) {
                 callback.onLoadFailed(e)
             } finally {

android/app/src/main/kotlin/deckers/thibault/aves/metadata/ExifInterfaceHelper.kt

@@ -10,12 +10,15 @@ import com.drew.metadata.exif.makernotes.OlympusImageProcessingMakernoteDirector
 import com.drew.metadata.exif.makernotes.OlympusMakernoteDirectory
 import deckers.thibault.aves.utils.LogUtils
 import java.util.*
+import kotlin.math.abs
 import kotlin.math.floor
 import kotlin.math.roundToLong
 
 object ExifInterfaceHelper {
     private val LOG_TAG = LogUtils.createTag(ExifInterfaceHelper::class.java)
 
+    private const val precisionErrorTolerance = 1e-10
+
     // ExifInterface always states it has the following attributes
     // and returns "0" instead of "null" when they are actually missing
     private val neverNullTags = listOf(
@@ -279,7 +282,7 @@ object ExifInterfaceHelper {
     private fun toRational(s: String?): Rational? {
         s ?: return null
 
-        // convert "12345/100"
+        // e.g. "12345/100" to Rational(12345, 100)
         val parts = s.split("/")
         if (parts.size == 2) {
             val numerator = parts[0].toLongOrNull() ?: return null
@@ -287,9 +290,20 @@ object ExifInterfaceHelper {
             return Rational(numerator, denominator)
         }
 
-        // convert "123.45"
         var d = s.toDoubleOrNull() ?: return null
         if (d == 0.0) return Rational(0, 1)
+
+        // e.g. "0.02564102564102564" to Rational(1, 39)
+        if (d < 1) {
+            val numerator = 1L
+            val f = numerator / d
+            val denominator = f.roundToLong()
+            if (abs(f - denominator) < precisionErrorTolerance) {
+                return Rational(numerator, denominator)
+            }
+        }
+
+        // e.g. "123.45" to Rational(12345, 100)
         var denominator: Long = 1
         while (d != floor(d)) {
             denominator *= 10
@@ -321,6 +335,24 @@ object ExifInterfaceHelper {
         }
     }
 
+    fun ExifInterface.getSafeDouble(tag: String, save: (value: Double) -> Unit) {
+        if (this.hasAttribute(tag)) {
+            val value = this.getAttributeDouble(tag, Double.NaN)
+            if (!value.isNaN()) {
+                save(value)
+            }
+        }
+    }
+
+    fun ExifInterface.getSafeRational(tag: String, save: (value: Rational) -> Unit) {
+        if (this.hasAttribute(tag)) {
+            val value = toRational(this.getAttribute(tag))
+            if (value != null) {
+                save(value)
+            }
+        }
+    }
+
     fun ExifInterface.getSafeDateMillis(tag: String, save: (value: Long) -> Unit) {
         if (this.hasAttribute(tag)) {
             // TODO TLAD parse date with "yyyy:MM:dd HH:mm:ss" or find the original long

android/app/src/main/kotlin/deckers/thibault/aves/model/SourceImageEntry.kt

@@ -123,7 +123,8 @@ class SourceImageEntry {
             fillVideoByMediaMetadataRetriever(context)
             if (isSized && hasDuration) return this
         }
-        if (MimeTypes.isSupportedByMetadataExtractor(sourceMimeType)) {
+        // skip metadata-extractor for raw images because it reports the decoded dimensions instead of the raw dimensions
+        if (!MimeTypes.isRaw(sourceMimeType) && MimeTypes.isSupportedByMetadataExtractor(sourceMimeType)) {
             fillByMetadataExtractor(context)
             if (isSized && foundExif) return this
         }
@@ -176,7 +177,6 @@ class SourceImageEntry {
                         dir.getSafeLong(Mp4Directory.TAG_DURATION) { durationMillis = it }
                     }
                 } else {
-                    // EXIF, if defined, should override metadata found in other directories
                     for (dir in metadata.getDirectoriesOfType(ExifIFD0Directory::class.java)) {
                         foundExif = true
                         dir.getSafeInt(ExifIFD0Directory.TAG_IMAGE_WIDTH) { width = it }
@@ -185,15 +185,15 @@ class SourceImageEntry {
                         dir.getSafeDateMillis(ExifIFD0Directory.TAG_DATETIME) { sourceDateTakenMillis = it }
                     }
 
-                    if (!foundExif) {
+                    // dimensions reported in EXIF do not always match the image
-                        for (dir in metadata.getDirectoriesOfType(JpegDirectory::class.java)) {
+                    // so we fetch them from the format directory if available
-                            dir.getSafeInt(JpegDirectory.TAG_IMAGE_WIDTH) { width = it }
+                    for (dir in metadata.getDirectoriesOfType(JpegDirectory::class.java)) {
-                            dir.getSafeInt(JpegDirectory.TAG_IMAGE_HEIGHT) { height = it }
+                        dir.getSafeInt(JpegDirectory.TAG_IMAGE_WIDTH) { width = it }
-                        }
+                        dir.getSafeInt(JpegDirectory.TAG_IMAGE_HEIGHT) { height = it }
-                        for (dir in metadata.getDirectoriesOfType(PsdHeaderDirectory::class.java)) {
+                    }
-                            dir.getSafeInt(PsdHeaderDirectory.TAG_IMAGE_WIDTH) { width = it }
+                    for (dir in metadata.getDirectoriesOfType(PsdHeaderDirectory::class.java)) {
-                            dir.getSafeInt(PsdHeaderDirectory.TAG_IMAGE_HEIGHT) { height = it }
+                        dir.getSafeInt(PsdHeaderDirectory.TAG_IMAGE_WIDTH) { width = it }
-                        }
+                        dir.getSafeInt(PsdHeaderDirectory.TAG_IMAGE_HEIGHT) { height = it }
                     }
                 }
             }
@@ -225,8 +225,9 @@ class SourceImageEntry {
     private fun fillByBitmapDecode(context: Context) {
         try {
             StorageUtils.openInputStream(context, uri)?.use { input ->
-                val options = BitmapFactory.Options()
+                val options = BitmapFactory.Options().apply {
-                options.inJustDecodeBounds = true
+                    inJustDecodeBounds = true
+                }
                 BitmapFactory.decodeStream(input, null, options)
                 width = options.outWidth
                 height = options.outHeight

android/app/src/main/kotlin/deckers/thibault/aves/model/provider/MediaStoreImageProvider.kt

@@ -144,11 +144,14 @@ class MediaStoreImageProvider : ImageProvider() {
                             "contentId" to contentId,
                         )
 
-                        if ((width <= 0 || height <= 0) && needSize(mimeType)
+                        if (MimeTypes.isRaw(mimeType)
+                            || (width <= 0 || height <= 0) && needSize(mimeType)
                             || durationMillis == 0L && needDuration
                         ) {
-                            // some images are incorrectly registered in the Media Store,
+                            // Some images are incorrectly registered in the Media Store,
-                            // they are valid but miss some attributes, such as width, height, orientation
+                            // missing some attributes such as width, height, orientation.
+                            // Also, the reported size of raw images is inconsistent across devices
+                            // and Android versions (sometimes the raw size, sometimes the decoded size).
                             val entry = SourceImageEntry(entryMap).fillPreCatalogMetadata(context)
                             entryMap = entry.toMap()
                         }

android/app/src/main/kotlin/deckers/thibault/aves/utils/BitmapUtils.kt

@@ -5,8 +5,22 @@ import android.graphics.Bitmap
 import com.bumptech.glide.Glide
 import com.bumptech.glide.load.resource.bitmap.TransformationUtils
 import deckers.thibault.aves.metadata.Metadata.getExifCode
+import java.io.ByteArrayOutputStream
 
 object BitmapUtils {
+    fun Bitmap.getBytes(canHaveAlpha: Boolean = false, quality: Int = 100, recycle: Boolean = true): ByteArray {
+        val stream = ByteArrayOutputStream()
+        // we compress the bitmap because Flutter cannot decode the raw bytes
+        // `Bitmap.CompressFormat.PNG` is slower than `JPEG`, but it allows transparency
+        if (canHaveAlpha) {
+            this.compress(Bitmap.CompressFormat.PNG, quality, stream)
+        } else {
+            this.compress(Bitmap.CompressFormat.JPEG, quality, stream)
+        }
+        if (recycle) this.recycle()
+        return stream.toByteArray()
+    }
+
     fun applyExifOrientation(context: Context, bitmap: Bitmap?, rotationDegrees: Int?, isFlipped: Boolean?): Bitmap? {
         if (bitmap == null || rotationDegrees == null || isFlipped == null) return bitmap
         if (rotationDegrees == 0 && !isFlipped) return bitmap

android/app/src/main/kotlin/deckers/thibault/aves/utils/MimeTypes.kt

@@ -16,7 +16,16 @@ object MimeTypes {
     const val WEBP = "image/webp"
 
     // raw raster
+    private const val ARW = "image/x-sony-arw"
+    private const val CR2 = "image/x-canon-cr2"
     private const val DNG = "image/x-adobe-dng"
+    private const val NEF = "image/x-nikon-nef"
+    private const val NRW = "image/x-nikon-nrw"
+    private const val ORF = "image/x-olympus-orf"
+    private const val PEF = "image/x-pentax-pef"
+    private const val RAF = "image/x-fuji-raf"
+    private const val RW2 = "image/x-panasonic-rw2"
+    private const val SRW = "image/x-samsung-srw"
 
     // vector
     const val SVG = "image/svg+xml"
@@ -35,6 +44,13 @@ object MimeTypes {
         else -> isVideo(mimeType)
     }
 
+    fun isRaw(mimeType: String?): Boolean {
+        return when (mimeType) {
+            ARW, CR2, DNG, NEF, NRW, ORF, PEF, RAF, RW2, SRW -> true
+            else -> false
+        }
+    }
+
     // returns whether the specified MIME type represents
     // a raster image format that allows an alpha channel
     fun canHaveAlpha(mimeType: String?) = when (mimeType) {
@@ -42,7 +58,7 @@ object MimeTypes {
         else -> false
     }
 
-    // as of Flutter v1.22.0
+    // as of Flutter v1.22.0, with additional custom handling for SVG
     fun isSupportedByFlutter(mimeType: String, rotationDegrees: Int?, isFlipped: Boolean?) = when (mimeType) {
         JPEG, GIF, WEBP, BMP, WBMP, ICO, SVG -> true
         PNG -> rotationDegrees ?: 0 == 0 && !(isFlipped ?: false)
@@ -71,4 +87,8 @@ object MimeTypes {
         DNG, PNG -> true
         else -> false
     }
+
+    // extensions
+
+    val tiffExtensionPattern = Regex(".*\\.tiff?", RegexOption.IGNORE_CASE)
 }

android/app/src/main/res/values-v28/styles.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <style name="AppTheme" parent="@android:style/Theme.Black.NoTitleBar">
+    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
         <item name="android:windowTranslucentNavigation">@bool/translucentNavBar</item> <!-- API19+, tinted background & request the SYSTEM_UI_FLAG_LAYOUT_STABLE and SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN flags -->
         <item name="android:windowLayoutInDisplayCutoutMode">shortEdges</item> <!-- API28+, draws next to the notch in fullscreen -->
     </style>

android/app/src/main/res/values/styles.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <style name="AppTheme" parent="@android:style/Theme.Black.NoTitleBar">
+    <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
         <item name="android:windowTranslucentNavigation">@bool/translucentNavBar</item> <!-- API19+, tinted background & request the SYSTEM_UI_FLAG_LAYOUT_STABLE and SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN flags -->
     </style>
 </resources>

lib/model/filters/location.dart

@@ -43,7 +43,7 @@ class LocationFilter extends CollectionFilter {
   @override
   Widget iconBuilder(BuildContext context, double size, {bool showGenericIcon = true, bool embossed = false}) {
     final flag = countryCodeToFlag(_countryCode);
-    // as of Flutter v1.22.0-12.1.pre emoji shadows are rendered as colorful duplicates,
+    // as of Flutter v1.22.3, emoji shadows are rendered as colorful duplicates,
     // not filled with the shadow color as expected, so we remove them
     if (flag != null) return Text(flag, style: TextStyle(fontSize: size, shadows: []));
     return Icon(_location.isEmpty ? AIcons.locationOff : AIcons.location, size: size);

lib/model/filters/mime.dart

@@ -1,5 +1,6 @@
 import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/model/mime_types.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
@@ -34,7 +35,7 @@ class MimeFilter extends CollectionFilter {
       _label ??= lowMime.split('/')[0].toUpperCase();
     } else {
       _filter = (entry) => entry.mimeType == lowMime;
-      _label = displayType(lowMime);
+      _label = MimeTypes.displayType(lowMime);
     }
     _icon ??= AIcons.vector;
   }
@@ -50,18 +51,6 @@ class MimeFilter extends CollectionFilter {
         'mime': mime,
       };
 
-  static String displayType(String mime) {
-    final patterns = [
-      RegExp('.*/'), // remove type, keep subtype
-      RegExp('(X-|VND.(WAP.)?)'), // noisy prefixes
-      '+XML', // noisy suffix
-      RegExp('ADOBE\\\.'), // for PSD
-    ];
-    mime = mime.toUpperCase();
-    patterns.forEach((pattern) => mime = mime.replaceFirst(pattern, ''));
-    return mime;
-  }
-
   @override
   bool filter(ImageEntry entry) => _filter(entry);
 

lib/model/image_entry.dart

@@ -169,6 +169,27 @@ class ImageEntry {
   // guess whether this is a photo, according to file type (used as a hint to e.g. display megapixels)
   bool get isPhoto => [MimeTypes.heic, MimeTypes.heif, MimeTypes.jpeg].contains(mimeType) || isRaw;
 
+  // Android's `BitmapRegionDecoder` documentation states that "only the JPEG and PNG formats are supported"
+  // but in practice (tested on API 25, 27, 29), it successfully decodes the formats listed below,
+  // and it actually fails to decode GIF, DNG and animated WEBP. Other formats were not tested.
+  bool get canTile =>
+      [
+        MimeTypes.heic,
+        MimeTypes.heif,
+        MimeTypes.jpeg,
+        MimeTypes.webp,
+        MimeTypes.arw,
+        MimeTypes.cr2,
+        MimeTypes.nef,
+        MimeTypes.nrw,
+        MimeTypes.orf,
+        MimeTypes.pef,
+        MimeTypes.raf,
+        MimeTypes.rw2,
+        MimeTypes.srw,
+      ].contains(mimeType) &&
+      !isAnimated;
+
   bool get isRaw => MimeTypes.rawImages.contains(mimeType);
 
   bool get isVideo => mimeType.startsWith('video');

lib/model/image_metadata.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/widgets.dart';
 import 'package:geocoder/model.dart';
+import 'package:intl/intl.dart';
 
 class DateMetadata {
   final int contentId, dateMillis;
@@ -109,23 +110,29 @@ class CatalogMetadata {
 class OverlayMetadata {
   final String aperture, exposureTime, focalLength, iso;
 
+  static final apertureFormat = NumberFormat('0.0', 'en_US');
+  static final focalLengthFormat = NumberFormat('0.#', 'en_US');
+
   OverlayMetadata({
-    String aperture,
+    double aperture,
-    this.exposureTime,
+    String exposureTime,
-    this.focalLength,
+    double focalLength,
-    this.iso,
+    int iso,
-  }) : aperture = aperture.replaceFirst('f', 'ƒ');
+  })  : aperture = aperture != null ? 'ƒ/${apertureFormat.format(aperture)}' : null,
+        exposureTime = exposureTime,
+        focalLength = focalLength != null ? '${focalLengthFormat.format(focalLength)} mm' : null,
+        iso = iso != null ? 'ISO$iso' : null;
 
   factory OverlayMetadata.fromMap(Map map) {
     return OverlayMetadata(
-      aperture: map['aperture'] ?? '',
+      aperture: map['aperture'] as double,
-      exposureTime: map['exposureTime'] ?? '',
+      exposureTime: map['exposureTime'] as String,
-      focalLength: map['focalLength'] ?? '',
+      focalLength: map['focalLength'] as double,
-      iso: map['iso'] ?? '',
+      iso: map['iso'] as int,
     );
   }
 
-  bool get isEmpty => aperture.isEmpty && exposureTime.isEmpty && focalLength.isEmpty && iso.isEmpty;
+  bool get isEmpty => aperture == null && exposureTime == null && focalLength == null && iso == null;
 
   @override
   String toString() {

lib/model/mime_types.dart

@@ -41,5 +41,17 @@ class MimeTypes {
 
   // groups
   static const List<String> rawImages = [arw, cr2, crw, dcr, dng, erf, k25, kdc, mrw, nef, nrw, orf, pef, raf, raw, rw2, sr2, srf, srw, x3f];
-  static const List<String> undecodable = [crw, psd, tiff]; // TODO TLAD make it dynamic if it depends on OS/lib versions
+  static const List<String> undecodable = [crw, psd]; // TODO TLAD make it dynamic if it depends on OS/lib versions
+
+  static String displayType(String mime) {
+    final patterns = [
+      RegExp('.*/'), // remove type, keep subtype
+      RegExp('(X-|VND.(WAP.)?)'), // noisy prefixes
+      '+XML', // noisy suffix
+      RegExp('ADOBE\\\.'), // for PSD
+    ];
+    mime = mime.toUpperCase();
+    patterns.forEach((pattern) => mime = mime.replaceFirst(pattern, ''));
+    return mime;
+  }
 }

lib/model/settings/settings.dart

@@ -45,6 +45,7 @@ class Settings extends ChangeNotifier {
   static const pinnedFiltersKey = 'pinned_filters';
 
   // viewer
+  static const showOverlayMinimapKey = 'show_overlay_minimap';
   static const showOverlayShootingDetailsKey = 'show_overlay_shooting_details';
 
   // info
@@ -159,6 +160,10 @@ class Settings extends ChangeNotifier {
 
   // viewer
 
+  bool get showOverlayMinimap => getBoolOrDefault(showOverlayMinimapKey, false);
+
+  set showOverlayMinimap(bool newValue) => setAndNotify(showOverlayMinimapKey, newValue);
+
   bool get showOverlayShootingDetails => getBoolOrDefault(showOverlayShootingDetailsKey, true);
 
   set showOverlayShootingDetails(bool newValue) => setAndNotify(showOverlayShootingDetailsKey, newValue);

lib/services/image_file_service.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 import 'dart:convert';
+import 'dart:math';
 import 'dart:typed_data';
 
 import 'package:aves/model/image_entry.dart';
@@ -113,6 +114,43 @@ class ImageFileService {
     return Future.sync(() => null);
   }
 
+  // `rect`: region to decode, with coordinates in reference to `imageSize`
+  static Future<Uint8List> getRegion(
+    String uri,
+    String mimeType,
+    int rotationDegrees,
+    bool isFlipped,
+    int sampleSize,
+    Rectangle<int> regionRect,
+    Size imageSize, {
+    Object taskKey,
+    int priority,
+  }) {
+    return servicePolicy.call(
+      () async {
+        try {
+          final result = await platform.invokeMethod('getRegion', <String, dynamic>{
+            'uri': uri,
+            'mimeType': mimeType,
+            'sampleSize': sampleSize,
+            'regionX': regionRect.left,
+            'regionY': regionRect.top,
+            'regionWidth': regionRect.width,
+            'regionHeight': regionRect.height,
+            'imageWidth': imageSize.width.toInt(),
+            'imageHeight': imageSize.height.toInt(),
+          });
+          return result as Uint8List;
+        } on PlatformException catch (e) {
+          debugPrint('getRegion failed with code=${e.code}, exception=${e.message}, details=${e.details}');
+        }
+        return null;
+      },
+      priority: priority ?? ServiceCallPriority.getRegion,
+      key: taskKey,
+    );
+  }
+
   static Future<Uint8List> getThumbnail(
     String uri,
     String mimeType,
@@ -160,9 +198,11 @@ class ImageFileService {
     }
   }
 
+  static bool cancelRegion(Object taskKey) => servicePolicy.pause(taskKey, [ServiceCallPriority.getRegion]);
+
   static bool cancelThumbnail(Object taskKey) => servicePolicy.pause(taskKey, [ServiceCallPriority.getFastThumbnail, ServiceCallPriority.getSizedThumbnail]);
 
-  static Future<T> resumeThumbnail<T>(Object taskKey) => servicePolicy.resume<T>(taskKey);
+  static Future<T> resumeLoading<T>(Object taskKey) => servicePolicy.resume<T>(taskKey);
 
   static Stream<ImageOpEvent> delete(Iterable<ImageEntry> entries) {
     try {

lib/services/metadata_service.dart

@@ -43,6 +43,7 @@ class MetadataService {
         final result = await platform.invokeMethod('getCatalogMetadata', <String, dynamic>{
           'mimeType': entry.mimeType,
           'uri': entry.uri,
+          'path': entry.path,
         }) as Map;
         result['contentId'] = entry.contentId;
         return CatalogMetadata.fromMap(result);
@@ -64,7 +65,7 @@ class MetadataService {
     if (entry.isSvg) return null;
 
     try {
-      // return map with string descriptions for: 'aperture' 'exposureTime' 'focalLength' 'iso'
+      // return map with values for: 'aperture' (double), 'exposureTime' (description), 'focalLength' (double), 'iso' (int)
       final result = await platform.invokeMethod('getOverlayMetadata', <String, dynamic>{
         'mimeType': entry.mimeType,
         'uri': entry.uri,
@@ -76,6 +77,19 @@ class MetadataService {
     return null;
   }
 
+  static Future<Map> getBitmapFactoryInfo(ImageEntry entry) async {
+    try {
+      // return map with all data available when decoding image bounds with `BitmapFactory`
+      final result = await platform.invokeMethod('getBitmapFactoryInfo', <String, dynamic>{
+        'uri': entry.uri,
+      }) as Map;
+      return result;
+    } on PlatformException catch (e) {
+      debugPrint('getBitmapFactoryInfo failed with code=${e.code}, exception=${e.message}, details=${e.details}');
+    }
+    return {};
+  }
+
   static Future<Map> getContentResolverMetadata(ImageEntry entry) async {
     try {
       // return map with all data available from the content resolver
@@ -92,7 +106,7 @@ class MetadataService {
 
   static Future<Map> getExifInterfaceMetadata(ImageEntry entry) async {
     try {
-      // return map with all data available from the ExifInterface library
+      // return map with all data available from the `ExifInterface` library
       final result = await platform.invokeMethod('getExifInterfaceMetadata', <String, dynamic>{
         'uri': entry.uri,
       }) as Map;
@@ -105,7 +119,7 @@ class MetadataService {
 
   static Future<Map> getMediaMetadataRetrieverMetadata(ImageEntry entry) async {
     try {
-      // return map with all data available from the MediaMetadataRetriever
+      // return map with all data available from `MediaMetadataRetriever`
       final result = await platform.invokeMethod('getMediaMetadataRetrieverMetadata', <String, dynamic>{
         'uri': entry.uri,
       }) as Map;
@@ -116,6 +130,19 @@ class MetadataService {
     return {};
   }
 
+  static Future<Map> getMetadataExtractorSummary(ImageEntry entry) async {
+    try {
+      // return map with the mime type and tag count for each directory found by `metadata-extractor`
+      final result = await platform.invokeMethod('getMetadataExtractorSummary', <String, dynamic>{
+        'uri': entry.uri,
+      }) as Map;
+      return result;
+    } on PlatformException catch (e) {
+      debugPrint('getMetadataExtractorSummary failed with code=${e.code}, exception=${e.message}, details=${e.details}');
+    }
+    return {};
+  }
+
   static Future<List<Uint8List>> getEmbeddedPictures(String uri) async {
     try {
       final result = await platform.invokeMethod('getEmbeddedPictures', <String, dynamic>{

lib/services/service_policy.dart

@@ -7,10 +7,13 @@ import 'package:tuple/tuple.dart';
 final ServicePolicy servicePolicy = ServicePolicy._private();
 
 class ServicePolicy {
+  final StreamController<QueueState> _queueStreamController = StreamController<QueueState>.broadcast();
   final Map<Object, Tuple2<int, _Task>> _paused = {};
   final SplayTreeMap<int, Queue<_Task>> _queues = SplayTreeMap();
   _Task _running;
 
+  Stream<QueueState> get queueStream => _queueStreamController.stream;
+
   ServicePolicy._private();
 
   Future<T> call<T>(
@@ -60,6 +63,7 @@ class ServicePolicy {
   Queue<_Task> _getQueue(int priority) => _queues.putIfAbsent(priority, () => Queue<_Task>());
 
   void _pickNext() {
+    _notifyQueueState();
     if (_running != null) return;
     final queue = _queues.entries.firstWhere((kv) => kv.value.isNotEmpty, orElse: () => null)?.value;
     _running = queue?.removeFirst();
@@ -90,6 +94,13 @@ class ServicePolicy {
   }
 
   bool isPaused(Object key) => _paused.containsKey(key);
+
+  void _notifyQueueState() {
+    if (!_queueStreamController.hasListener) return;
+
+    final queueByPriority = Map.fromEntries(_queues.entries.map((kv) => MapEntry(kv.key, kv.value.length)));
+    _queueStreamController.add(QueueState(queueByPriority));
+  }
 }
 
 class _Task {
@@ -104,8 +115,15 @@ class CancelledException {}
 
 class ServiceCallPriority {
   static const int getFastThumbnail = 100;
+  static const int getRegion = 150;
   static const int getSizedThumbnail = 200;
   static const int normal = 500;
   static const int getMetadata = 1000;
   static const int getLocation = 1000;
 }
+
+class QueueState {
+  final Map<int, int> queueByPriority;
+
+  const QueueState(this.queueByPriority);
+}

lib/utils/constants.dart

@@ -3,7 +3,7 @@ import 'package:flutter/painting.dart';
 import 'package:tuple/tuple.dart';
 
 class Constants {
-  // as of Flutter v1.11.0, overflowing `Text` miscalculates height and some text (e.g. 'Å') is clipped
+  // as of Flutter v1.22.3, overflowing `Text` miscalculates height and some text (e.g. 'Å') is clipped
   // so we give it a `strutStyle` with a slightly larger height
   static const overflowStrutStyle = StrutStyle(height: 1.3);
 
@@ -18,13 +18,20 @@ class Constants {
     offset: Offset(0.5, 1.0),
   );
 
-  static const String unknown = 'unknown';
+  static const String overlayUnknown = '—'; // em dash
+  static const String infoUnknown = 'unknown';
 
   static const pointNemo = Tuple2(-48.876667, -123.393333);
 
   static const int infoGroupMaxValueLength = 140;
 
   static const List<Dependency> androidDependencies = [
+    Dependency(
+      name: 'Android-TiffBitmapFactory',
+      license: 'MIT',
+      licenseUrl: 'https://github.com/Beyka/Android-TiffBitmapFactory/blob/master/license.txt',
+      sourceUrl: 'https://github.com/Beyka/Android-TiffBitmapFactory',
+    ),
     Dependency(
       name: 'CWAC-Document',
       license: 'Apache 2.0',

lib/utils/durations.dart

@@ -27,6 +27,7 @@ class Durations {
   // fullscreen animations
   static const fullscreenPageAnimation = Duration(milliseconds: 300);
   static const fullscreenOverlayAnimation = Duration(milliseconds: 200);
+  static const fullscreenOverlayChangeAnimation = Duration(milliseconds: 150);
 
   // info
   static const mapStyleSwitchAnimation = Duration(milliseconds: 300);

lib/utils/geo_utils.dart

@@ -1,10 +1,10 @@
-import 'dart:math' as math;
+import 'dart:math';
 
 import 'package:intl/intl.dart';
 import 'package:tuple/tuple.dart';
 
 String _decimal2sexagesimal(final double degDecimal) {
-  double _round(final double value, {final int decimals = 6}) => (value * math.pow(10, decimals)).round() / math.pow(10, decimals);
+  double _round(final double value, {final int decimals = 6}) => (value * pow(10, decimals)).round() / pow(10, decimals);
 
   List<int> _split(final double value) {
     // NumberFormat is necessary to create digit after comma if the value

lib/utils/math_utils.dart

@@ -0,0 +1,11 @@
+import 'dart:math';
+
+const double _piOver180 = pi / 180.0;
+
+final double log2 = log(2);
+
+double toDegrees(num radians) => radians / _piOver180;
+
+double toRadians(num degrees) => degrees * _piOver180;
+
+int highestPowerOf2(num x) => x < 1 ? 0 : pow(2, (log(x) / log2).floor());

lib/utils/time_utils.dart

@@ -12,11 +12,11 @@ String formatDuration(Duration d) {
 }
 
 extension ExtraDateTime on DateTime {
-  bool isAtSameYearAs(DateTime other) => this != null && other != null && year == other.year;
+  bool isAtSameYearAs(DateTime other) => this?.year == other?.year;
 
-  bool isAtSameMonthAs(DateTime other) => isAtSameYearAs(other) && month == other.month;
+  bool isAtSameMonthAs(DateTime other) => isAtSameYearAs(other) && this?.month == other?.month;
 
-  bool isAtSameDayAs(DateTime other) => isAtSameMonthAs(other) && day == other.day;
+  bool isAtSameDayAs(DateTime other) => isAtSameMonthAs(other) && this?.day == other?.day;
 
   bool get isToday => isAtSameDayAs(DateTime.now());
 

lib/widgets/app_debug_page.dart

@@ -1,370 +0,0 @@
-import 'dart:collection';
-
-import 'package:aves/model/favourite_repo.dart';
-import 'package:aves/model/image_entry.dart';
-import 'package:aves/model/image_metadata.dart';
-import 'package:aves/model/metadata_db.dart';
-import 'package:aves/model/settings/settings.dart';
-import 'package:aves/model/source/collection_source.dart';
-import 'package:aves/services/android_app_service.dart';
-import 'package:aves/services/image_file_service.dart';
-import 'package:aves/utils/android_file_utils.dart';
-import 'package:aves/utils/file_utils.dart';
-import 'package:aves/widgets/common/data_providers/media_query_data_provider.dart';
-import 'package:aves/widgets/common/icons.dart';
-import 'package:aves/widgets/fullscreen/info/common.dart';
-import 'package:firebase_analytics/firebase_analytics.dart';
-import 'package:firebase_core/firebase_core.dart';
-import 'package:firebase_crashlytics/firebase_crashlytics.dart';
-import 'package:flutter/material.dart';
-import 'package:flutter/scheduler.dart';
-import 'package:flutter_svg/flutter_svg.dart';
-
-class AppDebugPage extends StatefulWidget {
-  static const routeName = '/debug';
-
-  final CollectionSource source;
-
-  const AppDebugPage({this.source});
-
-  @override
-  State<StatefulWidget> createState() => AppDebugPageState();
-}
-
-class AppDebugPageState extends State<AppDebugPage> {
-  Future<int> _dbFileSizeLoader;
-  Future<List<ImageEntry>> _dbEntryLoader;
-  Future<List<DateMetadata>> _dbDateLoader;
-  Future<List<CatalogMetadata>> _dbMetadataLoader;
-  Future<List<AddressDetails>> _dbAddressLoader;
-  Future<List<FavouriteRow>> _dbFavouritesLoader;
-  Future<Map> _envLoader;
-
-  List<ImageEntry> get entries => widget.source.rawEntries;
-
-  @override
-  void initState() {
-    super.initState();
-    _startDbReport();
-    _envLoader = AndroidAppService.getEnv();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return MediaQueryDataProvider(
-      child: DefaultTabController(
-        length: 4,
-        child: Scaffold(
-          appBar: AppBar(
-            title: Text('Debug'),
-            bottom: TabBar(
-              tabs: [
-                Tab(icon: Icon(AIcons.debug)),
-                Tab(icon: Icon(AIcons.settings)),
-                Tab(icon: Icon(AIcons.removableStorage)),
-                Tab(icon: Icon(AIcons.android)),
-              ],
-            ),
-          ),
-          body: SafeArea(
-            child: TabBarView(
-              children: [
-                _buildGeneralTabView(),
-                _buildSettingsTabView(),
-                _buildStorageTabView(),
-                _buildEnvTabView(),
-              ],
-            ),
-          ),
-        ),
-      ),
-    );
-  }
-
-  Widget _buildGeneralTabView() {
-    final catalogued = entries.where((entry) => entry.isCatalogued);
-    final withGps = catalogued.where((entry) => entry.hasGps);
-    final located = withGps.where((entry) => entry.isLocated);
-    return ListView(
-      padding: EdgeInsets.all(16),
-      children: [
-        Text('Time dilation'),
-        Slider(
-          value: timeDilation,
-          onChanged: (v) => setState(() => timeDilation = v),
-          min: 1.0,
-          max: 10.0,
-          divisions: 9,
-          label: '$timeDilation',
-        ),
-        Divider(),
-        Row(
-          children: [
-            Expanded(
-              child: Text('Crashlytics'),
-            ),
-            SizedBox(width: 8),
-            ElevatedButton(
-              onPressed: FirebaseCrashlytics.instance.crash,
-              child: Text('Crash'),
-            ),
-          ],
-        ),
-        Row(
-          children: [
-            Expanded(
-              child: Text('Analytics'),
-            ),
-            SizedBox(width: 8),
-            ElevatedButton(
-              onPressed: () => FirebaseAnalytics().logEvent(
-                name: 'debug_test',
-                parameters: {'time': DateTime.now().toIso8601String()},
-              ),
-              child: Text('Send event'),
-            ),
-          ],
-        ),
-        Text('Firebase data collection: ${Firebase.app().isAutomaticDataCollectionEnabled ? 'enabled' : 'disabled'}'),
-        Text('Crashlytics collection: ${FirebaseCrashlytics.instance.isCrashlyticsCollectionEnabled ? 'enabled' : 'disabled'}'),
-        Divider(),
-        Text('Entries: ${entries.length}'),
-        Text('Catalogued: ${catalogued.length}'),
-        Text('With GPS: ${withGps.length}'),
-        Text('With address: ${located.length}'),
-        Divider(),
-        Row(
-          children: [
-            Expanded(
-              child: Text('Image cache:\n\t${imageCache.currentSize}/${imageCache.maximumSize} items\n\t${formatFilesize(imageCache.currentSizeBytes)}/${formatFilesize(imageCache.maximumSizeBytes)}'),
-            ),
-            SizedBox(width: 8),
-            ElevatedButton(
-              onPressed: () {
-                imageCache.clear();
-                setState(() {});
-              },
-              child: Text('Clear'),
-            ),
-          ],
-        ),
-        Row(
-          children: [
-            Expanded(
-              child: Text('SVG cache: ${PictureProvider.cacheCount} items'),
-            ),
-            SizedBox(width: 8),
-            ElevatedButton(
-              onPressed: () {
-                PictureProvider.clearCache();
-                setState(() {});
-              },
-              child: Text('Clear'),
-            ),
-          ],
-        ),
-        Row(
-          children: [
-            Expanded(
-              child: Text('Glide disk cache: ?'),
-            ),
-            SizedBox(width: 8),
-            ElevatedButton(
-              onPressed: ImageFileService.clearSizedThumbnailDiskCache,
-              child: Text('Clear'),
-            ),
-          ],
-        ),
-        Divider(),
-        FutureBuilder<int>(
-          future: _dbFileSizeLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            return Row(
-              children: [
-                Expanded(
-                  child: Text('DB file size: ${formatFilesize(snapshot.data)}'),
-                ),
-                SizedBox(width: 8),
-                ElevatedButton(
-                  onPressed: () => metadataDb.reset().then((_) => _startDbReport()),
-                  child: Text('Reset'),
-                ),
-              ],
-            );
-          },
-        ),
-        FutureBuilder<List>(
-          future: _dbEntryLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            return Row(
-              children: [
-                Expanded(
-                  child: Text('DB entry rows: ${snapshot.data.length}'),
-                ),
-                SizedBox(width: 8),
-                ElevatedButton(
-                  onPressed: () => metadataDb.clearEntries().then((_) => _startDbReport()),
-                  child: Text('Clear'),
-                ),
-              ],
-            );
-          },
-        ),
-        FutureBuilder<List>(
-          future: _dbDateLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            return Row(
-              children: [
-                Expanded(
-                  child: Text('DB date rows: ${snapshot.data.length}'),
-                ),
-                SizedBox(width: 8),
-                ElevatedButton(
-                  onPressed: () => metadataDb.clearDates().then((_) => _startDbReport()),
-                  child: Text('Clear'),
-                ),
-              ],
-            );
-          },
-        ),
-        FutureBuilder<List>(
-          future: _dbMetadataLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            return Row(
-              children: [
-                Expanded(
-                  child: Text('DB metadata rows: ${snapshot.data.length}'),
-                ),
-                SizedBox(width: 8),
-                ElevatedButton(
-                  onPressed: () => metadataDb.clearMetadataEntries().then((_) => _startDbReport()),
-                  child: Text('Clear'),
-                ),
-              ],
-            );
-          },
-        ),
-        FutureBuilder<List>(
-          future: _dbAddressLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            return Row(
-              children: [
-                Expanded(
-                  child: Text('DB address rows: ${snapshot.data.length}'),
-                ),
-                SizedBox(width: 8),
-                ElevatedButton(
-                  onPressed: () => metadataDb.clearAddresses().then((_) => _startDbReport()),
-                  child: Text('Clear'),
-                ),
-              ],
-            );
-          },
-        ),
-        FutureBuilder<List>(
-          future: _dbFavouritesLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            return Row(
-              children: [
-                Expanded(
-                  child: Text('DB favourite rows: ${snapshot.data.length} (${favourites.count} in memory)'),
-                ),
-                SizedBox(width: 8),
-                ElevatedButton(
-                  onPressed: () => favourites.clear().then((_) => _startDbReport()),
-                  child: Text('Clear'),
-                ),
-              ],
-            );
-          },
-        ),
-      ],
-    );
-  }
-
-  Widget _buildSettingsTabView() {
-    return ListView(
-      padding: EdgeInsets.all(16),
-      children: [
-        Row(
-          children: [
-            Expanded(
-              child: Text('Settings'),
-            ),
-            SizedBox(width: 8),
-            ElevatedButton(
-              onPressed: () => settings.reset().then((_) => setState(() {})),
-              child: Text('Reset'),
-            ),
-          ],
-        ),
-        InfoRowGroup({
-          'collectionGroupFactor': '${settings.collectionGroupFactor}',
-          'collectionSortFactor': '${settings.collectionSortFactor}',
-          'collectionTileExtent': '${settings.collectionTileExtent}',
-          'infoMapZoom': '${settings.infoMapZoom}',
-          'pinnedFilters': '${settings.pinnedFilters}',
-          'searchHistory': '${settings.searchHistory}',
-        }),
-      ],
-    );
-  }
-
-  Widget _buildStorageTabView() {
-    return ListView(
-      padding: EdgeInsets.all(16),
-      children: [
-        ...androidFileUtils.storageVolumes.expand((v) => [
-              Text(v.path),
-              InfoRowGroup({
-                'description': '${v.description}',
-                'isEmulated': '${v.isEmulated}',
-                'isPrimary': '${v.isPrimary}',
-                'isRemovable': '${v.isRemovable}',
-                'state': '${v.state}',
-              }),
-              Divider(),
-            ])
-      ],
-    );
-  }
-
-  Widget _buildEnvTabView() {
-    return ListView(
-      padding: EdgeInsets.all(16),
-      children: [
-        FutureBuilder<Map>(
-          future: _envLoader,
-          builder: (context, snapshot) {
-            if (snapshot.hasError) return Text(snapshot.error.toString());
-            if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
-            final data = SplayTreeMap.of(snapshot.data.map((k, v) => MapEntry(k.toString(), v?.toString() ?? 'null')));
-            return InfoRowGroup(data);
-          },
-        ),
-      ],
-    );
-  }
-
-  void _startDbReport() {
-    _dbFileSizeLoader = metadataDb.dbFileSize();
-    _dbEntryLoader = metadataDb.loadEntries();
-    _dbDateLoader = metadataDb.loadDates();
-    _dbMetadataLoader = metadataDb.loadMetadataEntries();
-    _dbAddressLoader = metadataDb.loadAddresses();
-    _dbFavouritesLoader = metadataDb.loadFavourites();
-    setState(() {});
-  }
-}

lib/widgets/collection/grid/header_date.dart

@@ -56,6 +56,7 @@ class MonthSectionHeader extends StatelessWidget {
   static DateFormat ym = DateFormat.yMMMM();
 
   static String _formatDate(DateTime date) {
+    if (date == null) return 'Unknown';
     if (date.isThisMonth) return 'This month';
     if (date.isThisYear) return m.format(date);
     return ym.format(date);

lib/widgets/collection/grid/header_generic.dart

@@ -80,7 +80,7 @@ class SectionHeader extends StatelessWidget {
       final para = RenderParagraph(
         TextSpan(
           children: [
-            // `RenderParagraph` fails to lay out `WidgetSpan` offscreen as of Flutter v1.17.0
+            // as of Flutter v1.22.3, `RenderParagraph` fails to lay out `WidgetSpan` offscreen
             // so we use a hair space times a magic number to match width
             TextSpan(
               text: '\u200A' * (hasLeading ? 23 : 1),
@@ -214,7 +214,7 @@ class SectionSelectableLeading extends StatelessWidget {
                     child: IconButton(
                       iconSize: 26,
                       padding: EdgeInsets.only(top: 1),
-                      alignment: Alignment.topLeft,
+                      alignment: AlignmentDirectional.topStart,
                       icon: Icon(selected ? AIcons.selected : AIcons.unselected),
                       onPressed: onPressed,
                       tooltip: selected ? 'Deselect section' : 'Select section',

lib/widgets/collection/grid/list_sliver.dart

@@ -10,9 +10,9 @@ import 'package:aves/widgets/fullscreen/fullscreen_page.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
-// use a `SliverList` instead of multiple `SliverGrid` because having one `SliverGrid` per section does not scale up
+// Use a `SliverList` instead of multiple `SliverGrid` because having one `SliverGrid` per section does not scale up.
-// with the multiple `SliverGrid` solution, thumbnails at the beginning of each sections are built even though they are offscreen
+// With the multiple `SliverGrid` solution, thumbnails at the beginning of each sections are built even though they are offscreen
-// because of `RenderSliverMultiBoxAdaptor.addInitialChild` called by `RenderSliverGrid.performLayout` (line 547), as of Flutter v1.17.0
+// because of `RenderSliverMultiBoxAdaptor.addInitialChild` called by `RenderSliverGrid.performLayout` (line 547), as of Flutter v1.17.0.
 class CollectionListSliver extends StatelessWidget {
   const CollectionListSliver();
 

lib/widgets/collection/grid/scaling.dart

@@ -226,10 +226,13 @@ class _ScaleOverlayState extends State<ScaleOverlay> {
                     Positioned(
                       left: clampedCenter.dx - extent / 2,
                       top: clampedCenter.dy - extent / 2,
-                      child: DecoratedThumbnail(
+                      child: DefaultTextStyle(
-                        entry: widget.imageEntry,
+                        style: TextStyle(),
-                        extent: extent,
+                        child: DecoratedThumbnail(
-                        showOverlay: false,
+                          entry: widget.imageEntry,
+                          extent: extent,
+                          showOverlay: false,
+                        ),
                       ),
                     ),
                   ],

lib/widgets/collection/thumbnail/decorated.dart

@@ -64,7 +64,7 @@ class DecoratedThumbnail extends StatelessWidget {
       );
     }
     return Container(
-      decoration: BoxDecoration(
+      foregroundDecoration: BoxDecoration(
         border: Border.all(
           color: borderColor,
           width: borderWidth,

lib/widgets/collection/thumbnail/error.dart

@@ -1,11 +1,17 @@
-import 'package:aves/widgets/common/icons.dart';
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/model/mime_types.dart';
 import 'package:flutter/material.dart';
 
 class ErrorThumbnail extends StatelessWidget {
+  final ImageEntry entry;
   final double extent;
   final String tooltip;
 
-  const ErrorThumbnail({@required this.extent, @required this.tooltip});
+  const ErrorThumbnail({
+    @required this.entry,
+    @required this.extent,
+    @required this.tooltip,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -13,10 +19,13 @@ class ErrorThumbnail extends StatelessWidget {
       child: Tooltip(
         message: tooltip,
         preferBelow: false,
-        child: Icon(
+        child: Text(
-          AIcons.error,
+          MimeTypes.displayType(entry.mimeType),
-          size: extent / 2,
+          style: TextStyle(
-          color: Colors.blueGrey,
+            color: Colors.blueGrey,
+            fontSize: extent / 5,
+          ),
+          textAlign: TextAlign.center,
         ),
       ),
     );

lib/widgets/collection/thumbnail/overlay.dart

@@ -97,7 +97,7 @@ class ThumbnailSelectionOverlay extends StatelessWidget {
                   );
                   child = AnimatedContainer(
                     duration: duration,
-                    alignment: Alignment.topRight,
+                    alignment: AlignmentDirectional.topEnd,
                     color: selected ? Colors.black54 : Colors.transparent,
                     child: child,
                   );

lib/widgets/collection/thumbnail/raster.dart

@@ -71,8 +71,6 @@ class _ThumbnailRasterImageState extends State<ThumbnailRasterImage> {
     _pauseProvider();
   }
 
-  bool get isSupported => entry.canDecode;
-
   void _initProvider() {
     if (!entry.canDecode) return;
 
@@ -101,6 +99,7 @@ class _ThumbnailRasterImageState extends State<ThumbnailRasterImage> {
   Widget build(BuildContext context) {
     if (!entry.canDecode) {
       return ErrorThumbnail(
+        entry: entry,
         extent: extent,
         tooltip: '${entry.mimeType} not supported',
       );
@@ -139,6 +138,7 @@ class _ThumbnailRasterImageState extends State<ThumbnailRasterImage> {
               );
             },
             errorBuilder: (context, error, stackTrace) => ErrorThumbnail(
+              entry: entry,
               extent: extent,
               tooltip: error.toString(),
             ),

lib/widgets/common/aves_expansion_tile.dart

@@ -9,12 +9,13 @@ class AvesExpansionTile extends StatelessWidget {
 
   const AvesExpansionTile({
     @required this.title,
-    @required this.children,
     this.expandedNotifier,
+    @required this.children,
   });
 
   @override
   Widget build(BuildContext context) {
+    final enabled = children?.isNotEmpty == true;
     return Theme(
       data: Theme.of(context).copyWith(
         // color used by the `ExpansionTileCard` for selected text and icons
@@ -27,12 +28,17 @@ class AvesExpansionTile extends StatelessWidget {
         title: HighlightTitle(
           title,
           fontSize: 18,
+          enabled: enabled,
+        ),
+        expandable: enabled,
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Divider(thickness: 1, height: 1),
+            SizedBox(height: 4),
+            if (enabled) ...children,
+          ],
         ),
-        children: [
-          Divider(thickness: 1, height: 1),
-          SizedBox(height: 4),
-          ...children,
-        ],
         baseColor: Colors.grey[900],
         expandedColor: Colors.grey[850],
       ),

lib/widgets/common/aves_filter_chip.dart

@@ -201,7 +201,10 @@ class _AvesFilterChipState extends State<AvesFilterChip> {
     if (widget.heroType == HeroType.always || widget.heroType == HeroType.onTap && _tapped) {
       chip = Hero(
         tag: filter,
-        child: chip,
+        child: DefaultTextStyle(
+          style: TextStyle(),
+          child: chip,
+        ),
       );
     }
     return chip;

lib/widgets/common/highlight_title.dart

@@ -5,11 +5,15 @@ import 'package:flutter/material.dart';
 class HighlightTitle extends StatelessWidget {
   final String name;
   final double fontSize;
+  final bool enabled;
 
   const HighlightTitle(
     this.name, {
     this.fontSize = 20,
-  });
+    this.enabled = true,
+  }) : assert(name != null);
+
+  static const disabledColor = Colors.grey;
 
   @override
   Widget build(BuildContext context) {
@@ -17,7 +21,7 @@ class HighlightTitle extends StatelessWidget {
       alignment: AlignmentDirectional.centerStart,
       child: Container(
         decoration: HighlightDecoration(
-          color: stringToColor(name),
+          color: enabled ? stringToColor(name) : disabledColor,
         ),
         margin: EdgeInsets.symmetric(vertical: 4.0),
         child: Text(

lib/widgets/common/image_providers/region_provider.dart

@@ -0,0 +1,131 @@
+import 'dart:async';
+import 'dart:math';
+import 'dart:ui' as ui show Codec;
+
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/services/image_file_service.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+class RegionProvider extends ImageProvider<RegionProviderKey> {
+  final RegionProviderKey key;
+
+  RegionProvider(this.key) : assert(key != null);
+
+  @override
+  Future<RegionProviderKey> obtainKey(ImageConfiguration configuration) {
+    return SynchronousFuture<RegionProviderKey>(key);
+  }
+
+  @override
+  ImageStreamCompleter load(RegionProviderKey key, DecoderCallback decode) {
+    return MultiFrameImageStreamCompleter(
+      codec: _loadAsync(key, decode),
+      scale: key.scale,
+      informationCollector: () sync* {
+        yield ErrorDescription('uri=${key.uri}, regionRect=${key.regionRect}');
+      },
+    );
+  }
+
+  Future<ui.Codec> _loadAsync(RegionProviderKey key, DecoderCallback decode) async {
+    final uri = key.uri;
+    final mimeType = key.mimeType;
+    try {
+      final bytes = await ImageFileService.getRegion(
+        uri,
+        mimeType,
+        key.rotationDegrees,
+        key.isFlipped,
+        key.sampleSize,
+        key.regionRect,
+        key.imageSize,
+        taskKey: key,
+      );
+      if (bytes == null) {
+        throw StateError('$uri ($mimeType) region loading failed');
+      }
+      return await decode(bytes);
+    } catch (error) {
+      debugPrint('$runtimeType _loadAsync failed with mimeType=$mimeType, uri=$uri, error=$error');
+      throw StateError('$mimeType region decoding failed');
+    }
+  }
+
+  @override
+  void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, RegionProviderKey key, ImageErrorListener handleError) {
+    ImageFileService.resumeLoading(key);
+    super.resolveStreamForKey(configuration, stream, key, handleError);
+  }
+
+  void pause() => ImageFileService.cancelRegion(key);
+}
+
+class RegionProviderKey {
+  final String uri, mimeType;
+  final int rotationDegrees, sampleSize;
+  final bool isFlipped;
+  final Rectangle<int> regionRect;
+  final Size imageSize;
+  final double scale;
+
+  const RegionProviderKey({
+    @required this.uri,
+    @required this.mimeType,
+    @required this.rotationDegrees,
+    @required this.isFlipped,
+    @required this.sampleSize,
+    @required this.regionRect,
+    @required this.imageSize,
+    this.scale = 1.0,
+  })  : assert(uri != null),
+        assert(mimeType != null),
+        assert(rotationDegrees != null),
+        assert(isFlipped != null),
+        assert(sampleSize != null),
+        assert(regionRect != null),
+        assert(imageSize != null),
+        assert(scale != null);
+
+  // do not store the entry as it is, because the key should be constant
+  // but the entry attributes may change over time
+  factory RegionProviderKey.fromEntry(
+    ImageEntry entry, {
+    @required int sampleSize,
+    @required Rectangle<int> rect,
+  }) {
+    return RegionProviderKey(
+      uri: entry.uri,
+      mimeType: entry.mimeType,
+      rotationDegrees: entry.rotationDegrees,
+      isFlipped: entry.isFlipped,
+      sampleSize: sampleSize,
+      regionRect: rect,
+      imageSize: Size(entry.width.toDouble(), entry.height.toDouble()),
+    );
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is RegionProviderKey && other.uri == uri && other.mimeType == mimeType && other.rotationDegrees == rotationDegrees && other.isFlipped == isFlipped && other.sampleSize == sampleSize && other.regionRect == regionRect && other.imageSize == imageSize && other.scale == scale;
+  }
+
+  @override
+  int get hashCode => hashValues(
+        uri,
+        mimeType,
+        rotationDegrees,
+        isFlipped,
+        mimeType,
+        sampleSize,
+        regionRect,
+        imageSize,
+        scale,
+      );
+
+  @override
+  String toString() {
+    return 'RegionProviderKey(uri=$uri, mimeType=$mimeType, rotationDegrees=$rotationDegrees, isFlipped=$isFlipped, sampleSize=$sampleSize, regionRect=$regionRect, imageSize=$imageSize, scale=$scale)';
+  }
+}

lib/widgets/common/image_providers/thumbnail_provider.dart

@@ -30,8 +30,8 @@ class ThumbnailProvider extends ImageProvider<ThumbnailProviderKey> {
   }
 
   Future<ui.Codec> _loadAsync(ThumbnailProviderKey key, DecoderCallback decode) async {
-    var uri = key.uri;
+    final uri = key.uri;
-    var mimeType = key.mimeType;
+    final mimeType = key.mimeType;
     try {
       final bytes = await ImageFileService.getThumbnail(
         uri,
@@ -55,7 +55,7 @@ class ThumbnailProvider extends ImageProvider<ThumbnailProviderKey> {
 
   @override
   void resolveStreamForKey(ImageConfiguration configuration, ImageStream stream, ThumbnailProviderKey key, ImageErrorListener handleError) {
-    ImageFileService.resumeThumbnail(key);
+    ImageFileService.resumeLoading(key);
     super.resolveStreamForKey(configuration, stream, key, handleError);
   }
 
@@ -105,7 +105,15 @@ class ThumbnailProviderKey {
   }
 
   @override
-  int get hashCode => hashValues(uri, mimeType, dateModifiedSecs, rotationDegrees, isFlipped, extent, scale);
+  int get hashCode => hashValues(
+        uri,
+        mimeType,
+        dateModifiedSecs,
+        rotationDegrees,
+        isFlipped,
+        extent,
+        scale,
+      );
 
   @override
   String toString() {

lib/widgets/common/image_providers/uri_image_provider.dart

@@ -73,7 +73,7 @@ class UriImage extends ImageProvider<UriImage> {
   @override
   bool operator ==(Object other) {
     if (other.runtimeType != runtimeType) return false;
-    return other is UriImage && other.uri == uri && other.mimeType == mimeType && other.scale == scale;
+    return other is UriImage && other.uri == uri && other.scale == scale;
   }
 
   @override

lib/widgets/debug/android_env.dart

@@ -0,0 +1,47 @@
+import 'dart:collection';
+
+import 'package:aves/services/android_app_service.dart';
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:aves/widgets/fullscreen/info/common.dart';
+import 'package:flutter/material.dart';
+
+class DebugAndroidEnvironmentSection extends StatefulWidget {
+  @override
+  _DebugAndroidEnvironmentSectionState createState() => _DebugAndroidEnvironmentSectionState();
+}
+
+class _DebugAndroidEnvironmentSectionState extends State<DebugAndroidEnvironmentSection> with AutomaticKeepAliveClientMixin {
+  Future<Map> _loader;
+
+  @override
+  void initState() {
+    super.initState();
+    _loader = AndroidAppService.getEnv();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    super.build(context);
+
+    return AvesExpansionTile(
+      title: 'Android Environment',
+      children: [
+        Padding(
+          padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+          child: FutureBuilder<Map>(
+            future: _loader,
+            builder: (context, snapshot) {
+              if (snapshot.hasError) return Text(snapshot.error.toString());
+              if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+              final data = SplayTreeMap.of(snapshot.data.map((k, v) => MapEntry(k.toString(), v?.toString() ?? 'null')));
+              return InfoRowGroup(data);
+            },
+          ),
+        ),
+      ],
+    );
+  }
+
+  @override
+  bool get wantKeepAlive => true;
+}

lib/widgets/debug/app_debug_page.dart

@@ -0,0 +1,107 @@
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/model/source/collection_source.dart';
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:aves/widgets/common/data_providers/media_query_data_provider.dart';
+import 'package:aves/widgets/debug/android_env.dart';
+import 'package:aves/widgets/debug/cache.dart';
+import 'package:aves/widgets/debug/database.dart';
+import 'package:aves/widgets/debug/firebase.dart';
+import 'package:aves/widgets/debug/overlay.dart';
+import 'package:aves/widgets/debug/settings.dart';
+import 'package:aves/widgets/debug/storage.dart';
+import 'package:aves/widgets/fullscreen/info/common.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
+
+class AppDebugPage extends StatefulWidget {
+  static const routeName = '/debug';
+
+  final CollectionSource source;
+
+  const AppDebugPage({this.source});
+
+  @override
+  State<StatefulWidget> createState() => AppDebugPageState();
+}
+
+class AppDebugPageState extends State<AppDebugPage> {
+  List<ImageEntry> get entries => widget.source.rawEntries;
+
+  static OverlayEntry _taskQueueOverlayEntry;
+
+  @override
+  Widget build(BuildContext context) {
+    return MediaQueryDataProvider(
+      child: Scaffold(
+        appBar: AppBar(
+          title: Text('Debug'),
+        ),
+        body: SafeArea(
+          child: ListView(
+            padding: EdgeInsets.all(8),
+            children: [
+              _buildGeneralTabView(),
+              DebugAndroidEnvironmentSection(),
+              DebugCacheSection(),
+              DebugAppDatabaseSection(),
+              DebugFirebaseSection(),
+              DebugSettingsSection(),
+              DebugStorageSection(),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+
+  Widget _buildGeneralTabView() {
+    final catalogued = entries.where((entry) => entry.isCatalogued);
+    final withGps = catalogued.where((entry) => entry.hasGps);
+    final located = withGps.where((entry) => entry.isLocated);
+    return AvesExpansionTile(
+      title: 'General',
+      children: [
+        Padding(
+          padding: EdgeInsets.all(8),
+          child: Text('Time dilation'),
+        ),
+        Slider(
+          value: timeDilation,
+          onChanged: (v) => setState(() => timeDilation = v),
+          min: 1.0,
+          max: 10.0,
+          divisions: 9,
+          label: '$timeDilation',
+        ),
+        SwitchListTile(
+          value: _taskQueueOverlayEntry != null,
+          onChanged: (v) {
+            _taskQueueOverlayEntry?.remove();
+            if (v) {
+              _taskQueueOverlayEntry = OverlayEntry(
+                builder: (context) => DebugTaskQueueOverlay(),
+              );
+              Overlay.of(context).insert(_taskQueueOverlayEntry);
+            } else {
+              _taskQueueOverlayEntry = null;
+            }
+            setState(() {});
+          },
+          title: Text('Show tasks overlay'),
+        ),
+        Divider(),
+        Padding(
+          padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+          child: InfoRowGroup(
+            {
+              'Entries': '${entries.length}',
+              'Catalogued': '${catalogued.length}',
+              'With GPS': '${withGps.length}',
+              'With address': '${located.length}',
+            },
+          ),
+        ),
+      ],
+    );
+  }
+}

lib/widgets/debug/cache.dart

@@ -0,0 +1,77 @@
+import 'package:aves/services/image_file_service.dart';
+import 'package:aves/utils/file_utils.dart';
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_svg/flutter_svg.dart';
+
+class DebugCacheSection extends StatefulWidget {
+  @override
+  _DebugCacheSectionState createState() => _DebugCacheSectionState();
+}
+
+class _DebugCacheSectionState extends State<DebugCacheSection> with AutomaticKeepAliveClientMixin {
+  @override
+  Widget build(BuildContext context) {
+    super.build(context);
+
+    return AvesExpansionTile(
+      title: 'Cache',
+      children: [
+        Padding(
+          padding: EdgeInsets.symmetric(horizontal: 8),
+          child: Column(
+            children: [
+              Row(
+                children: [
+                  Expanded(
+                    child: Text('Image cache:\n\t${imageCache.currentSize}/${imageCache.maximumSize} items\n\t${formatFilesize(imageCache.currentSizeBytes)}/${formatFilesize(imageCache.maximumSizeBytes)}'),
+                  ),
+                  SizedBox(width: 8),
+                  ElevatedButton(
+                    onPressed: () {
+                      imageCache.clear();
+
+                      setState(() {});
+                    },
+                    child: Text('Clear'),
+                  ),
+                ],
+              ),
+              Row(
+                children: [
+                  Expanded(
+                    child: Text('SVG cache: ${PictureProvider.cacheCount} items'),
+                  ),
+                  SizedBox(width: 8),
+                  ElevatedButton(
+                    onPressed: () {
+                      PictureProvider.clearCache();
+
+                      setState(() {});
+                    },
+                    child: Text('Clear'),
+                  ),
+                ],
+              ),
+              Row(
+                children: [
+                  Expanded(
+                    child: Text('Glide disk cache: ?'),
+                  ),
+                  SizedBox(width: 8),
+                  ElevatedButton(
+                    onPressed: ImageFileService.clearSizedThumbnailDiskCache,
+                    child: Text('Clear'),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+
+  @override
+  bool get wantKeepAlive => true;
+}

lib/widgets/debug/database.dart

@@ -0,0 +1,184 @@
+import 'package:aves/model/favourite_repo.dart';
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/model/image_metadata.dart';
+import 'package:aves/model/metadata_db.dart';
+import 'package:aves/utils/file_utils.dart';
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:flutter/material.dart';
+
+class DebugAppDatabaseSection extends StatefulWidget {
+  @override
+  _DebugAppDatabaseSectionState createState() => _DebugAppDatabaseSectionState();
+}
+
+class _DebugAppDatabaseSectionState extends State<DebugAppDatabaseSection> with AutomaticKeepAliveClientMixin {
+  Future<int> _dbFileSizeLoader;
+  Future<List<ImageEntry>> _dbEntryLoader;
+  Future<List<DateMetadata>> _dbDateLoader;
+  Future<List<CatalogMetadata>> _dbMetadataLoader;
+  Future<List<AddressDetails>> _dbAddressLoader;
+  Future<List<FavouriteRow>> _dbFavouritesLoader;
+
+  @override
+  void initState() {
+    super.initState();
+    _startDbReport();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    super.build(context);
+
+    return AvesExpansionTile(
+      title: 'Database',
+      children: [
+        Padding(
+          padding: EdgeInsets.symmetric(horizontal: 8),
+          child: Column(
+            children: [
+              FutureBuilder<int>(
+                future: _dbFileSizeLoader,
+                builder: (context, snapshot) {
+                  if (snapshot.hasError) return Text(snapshot.error.toString());
+
+                  if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+
+                  return Row(
+                    children: [
+                      Expanded(
+                        child: Text('DB file size: ${formatFilesize(snapshot.data)}'),
+                      ),
+                      SizedBox(width: 8),
+                      ElevatedButton(
+                        onPressed: () => metadataDb.reset().then((_) => _startDbReport()),
+                        child: Text('Reset'),
+                      ),
+                    ],
+                  );
+                },
+              ),
+              FutureBuilder<List>(
+                future: _dbEntryLoader,
+                builder: (context, snapshot) {
+                  if (snapshot.hasError) return Text(snapshot.error.toString());
+
+                  if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+
+                  return Row(
+                    children: [
+                      Expanded(
+                        child: Text('entry rows: ${snapshot.data.length}'),
+                      ),
+                      SizedBox(width: 8),
+                      ElevatedButton(
+                        onPressed: () => metadataDb.clearEntries().then((_) => _startDbReport()),
+                        child: Text('Clear'),
+                      ),
+                    ],
+                  );
+                },
+              ),
+              FutureBuilder<List>(
+                future: _dbDateLoader,
+                builder: (context, snapshot) {
+                  if (snapshot.hasError) return Text(snapshot.error.toString());
+
+                  if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+
+                  return Row(
+                    children: [
+                      Expanded(
+                        child: Text('date rows: ${snapshot.data.length}'),
+                      ),
+                      SizedBox(width: 8),
+                      ElevatedButton(
+                        onPressed: () => metadataDb.clearDates().then((_) => _startDbReport()),
+                        child: Text('Clear'),
+                      ),
+                    ],
+                  );
+                },
+              ),
+              FutureBuilder<List>(
+                future: _dbMetadataLoader,
+                builder: (context, snapshot) {
+                  if (snapshot.hasError) return Text(snapshot.error.toString());
+
+                  if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+
+                  return Row(
+                    children: [
+                      Expanded(
+                        child: Text('metadata rows: ${snapshot.data.length}'),
+                      ),
+                      SizedBox(width: 8),
+                      ElevatedButton(
+                        onPressed: () => metadataDb.clearMetadataEntries().then((_) => _startDbReport()),
+                        child: Text('Clear'),
+                      ),
+                    ],
+                  );
+                },
+              ),
+              FutureBuilder<List>(
+                future: _dbAddressLoader,
+                builder: (context, snapshot) {
+                  if (snapshot.hasError) return Text(snapshot.error.toString());
+
+                  if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+
+                  return Row(
+                    children: [
+                      Expanded(
+                        child: Text('address rows: ${snapshot.data.length}'),
+                      ),
+                      SizedBox(width: 8),
+                      ElevatedButton(
+                        onPressed: () => metadataDb.clearAddresses().then((_) => _startDbReport()),
+                        child: Text('Clear'),
+                      ),
+                    ],
+                  );
+                },
+              ),
+              FutureBuilder<List>(
+                future: _dbFavouritesLoader,
+                builder: (context, snapshot) {
+                  if (snapshot.hasError) return Text(snapshot.error.toString());
+
+                  if (snapshot.connectionState != ConnectionState.done) return SizedBox.shrink();
+
+                  return Row(
+                    children: [
+                      Expanded(
+                        child: Text('favourite rows: ${snapshot.data.length} (${favourites.count} in memory)'),
+                      ),
+                      SizedBox(width: 8),
+                      ElevatedButton(
+                        onPressed: () => favourites.clear().then((_) => _startDbReport()),
+                        child: Text('Clear'),
+                      ),
+                    ],
+                  );
+                },
+              ),
+            ],
+          ),
+        ),
+      ],
+    );
+  }
+
+  void _startDbReport() {
+    _dbFileSizeLoader = metadataDb.dbFileSize();
+    _dbEntryLoader = metadataDb.loadEntries();
+    _dbDateLoader = metadataDb.loadDates();
+    _dbMetadataLoader = metadataDb.loadMetadataEntries();
+    _dbAddressLoader = metadataDb.loadAddresses();
+    _dbFavouritesLoader = metadataDb.loadFavourites();
+    setState(() {});
+  }
+
+  @override
+  bool get wantKeepAlive => true;
+}

lib/widgets/debug/firebase.dart

@@ -0,0 +1,43 @@
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:aves/widgets/fullscreen/info/common.dart';
+import 'package:firebase_analytics/firebase_analytics.dart';
+import 'package:firebase_core/firebase_core.dart';
+import 'package:firebase_crashlytics/firebase_crashlytics.dart';
+import 'package:flutter/material.dart';
+
+class DebugFirebaseSection extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return AvesExpansionTile(
+      title: 'Firebase',
+      children: [
+        Padding(
+          padding: EdgeInsets.symmetric(horizontal: 8),
+          child: Row(
+            children: [
+              ElevatedButton(
+                onPressed: FirebaseCrashlytics.instance.crash,
+                child: Text('Crash'),
+              ),
+              SizedBox(width: 8),
+              ElevatedButton(
+                onPressed: () => FirebaseAnalytics().logEvent(
+                  name: 'debug_test',
+                  parameters: {'time': DateTime.now().toIso8601String()},
+                ),
+                child: Text('Send event'),
+              ),
+            ],
+          ),
+        ),
+        Padding(
+          padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+          child: InfoRowGroup({
+            'Firebase data collection enabled': '${Firebase.app().isAutomaticDataCollectionEnabled}',
+            'Crashlytics collection enabled': '${FirebaseCrashlytics.instance.isCrashlyticsCollectionEnabled}',
+          }),
+        )
+      ],
+    );
+  }
+}

lib/widgets/debug/overlay.dart

@@ -0,0 +1,39 @@
+import 'package:aves/services/service_policy.dart';
+import 'package:flutter/material.dart';
+
+class DebugTaskQueueOverlay extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return IgnorePointer(
+      child: DefaultTextStyle(
+        style: TextStyle(),
+        child: Align(
+          alignment: AlignmentDirectional.bottomStart,
+          child: SafeArea(
+            child: Container(
+              color: Colors.indigo[900].withAlpha(0xCC),
+              margin: EdgeInsets.only(
+                bottom: MediaQuery.of(context).viewInsets.bottom,
+              ),
+              padding: EdgeInsets.all(8),
+              child: StreamBuilder<QueueState>(
+                  stream: servicePolicy.queueStream,
+                  builder: (context, snapshot) {
+                    if (snapshot.hasError) return SizedBox.shrink();
+                    final queuedEntries = (snapshot.hasData ? snapshot.data.queueByPriority.entries.toList() : []);
+                    queuedEntries.sort((a, b) => a.key.compareTo(b.key));
+                    return Column(
+                      mainAxisSize: MainAxisSize.min,
+                      crossAxisAlignment: CrossAxisAlignment.stretch,
+                      children: [
+                        Text(queuedEntries.map((kv) => '${kv.key}: ${kv.value}').join(', ')),
+                      ],
+                    );
+                  }),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/widgets/debug/settings.dart

@@ -0,0 +1,40 @@
+import 'package:aves/model/settings/settings.dart';
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:aves/widgets/fullscreen/info/common.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+class DebugSettingsSection extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Consumer<Settings>(builder: (context, settings, child) {
+      String toMultiline(Iterable l) => l.isNotEmpty ? '\n${l.join('\n')}' : '$l';
+      return AvesExpansionTile(
+        title: 'Settings',
+        children: [
+          Padding(
+            padding: EdgeInsets.symmetric(horizontal: 8),
+            child: ElevatedButton(
+              onPressed: () => settings.reset(),
+              child: Text('Reset'),
+            ),
+          ),
+          SwitchListTile(
+            value: settings.hasAcceptedTerms,
+            onChanged: (v) => settings.hasAcceptedTerms = v,
+            title: Text('hasAcceptedTerms'),
+          ),
+          Padding(
+            padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+            child: InfoRowGroup({
+              'collectionTileExtent': '${settings.collectionTileExtent}',
+              'infoMapZoom': '${settings.infoMapZoom}',
+              'pinnedFilters': toMultiline(settings.pinnedFilters),
+              'searchHistory': toMultiline(settings.searchHistory),
+            }),
+          ),
+        ],
+      );
+    });
+  }
+}

lib/widgets/debug/storage.dart

@@ -0,0 +1,32 @@
+import 'package:aves/utils/android_file_utils.dart';
+import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:aves/widgets/fullscreen/info/common.dart';
+import 'package:flutter/material.dart';
+
+class DebugStorageSection extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return AvesExpansionTile(
+      title: 'Storage Volumes',
+      children: [
+        ...androidFileUtils.storageVolumes.expand((v) => [
+              Padding(
+                padding: EdgeInsets.all(8),
+                child: Text(v.path),
+              ),
+              Padding(
+                padding: EdgeInsets.symmetric(horizontal: 8),
+                child: InfoRowGroup({
+                  'description': '${v.description}',
+                  'isEmulated': '${v.isEmulated}',
+                  'isPrimary': '${v.isPrimary}',
+                  'isRemovable': '${v.isRemovable}',
+                  'state': '${v.state}',
+                }),
+              ),
+              Divider(),
+            ])
+      ],
+    );
+  }
+}

lib/widgets/drawer/app_drawer.dart

@@ -10,9 +10,9 @@ import 'package:aves/model/source/location.dart';
 import 'package:aves/model/source/tag.dart';
 import 'package:aves/utils/android_file_utils.dart';
 import 'package:aves/widgets/about/about_page.dart';
-import 'package:aves/widgets/app_debug_page.dart';
 import 'package:aves/widgets/common/aves_logo.dart';
 import 'package:aves/widgets/common/icons.dart';
+import 'package:aves/widgets/debug/app_debug_page.dart';
 import 'package:aves/widgets/drawer/collection_tile.dart';
 import 'package:aves/widgets/drawer/tile.dart';
 import 'package:aves/widgets/filter_grids/albums_page.dart';

lib/widgets/fullscreen/debug/metadata.dart

@@ -18,7 +18,7 @@ class MetadataTab extends StatefulWidget {
 }
 
 class _MetadataTabState extends State<MetadataTab> {
-  Future<Map> _contentResolverMetadataLoader, _exifInterfaceMetadataLoader, _mediaMetadataLoader;
+  Future<Map> _bitmapFactoryLoader, _contentResolverMetadataLoader, _exifInterfaceMetadataLoader, _mediaMetadataLoader, _metadataExtractorLoader;
 
   // MediaStore timestamp keys
   static const secondTimestampKeys = ['date_added', 'date_modified', 'date_expires', 'isPlayed'];
@@ -33,9 +33,11 @@ class _MetadataTabState extends State<MetadataTab> {
   }
 
   void _loadMetadata() {
+    _bitmapFactoryLoader = MetadataService.getBitmapFactoryInfo(entry);
     _contentResolverMetadataLoader = MetadataService.getContentResolverMetadata(entry);
     _exifInterfaceMetadataLoader = MetadataService.getExifInterfaceMetadata(entry);
     _mediaMetadataLoader = MetadataService.getMediaMetadataRetrieverMetadata(entry);
+    _metadataExtractorLoader = MetadataService.getMetadataExtractorSummary(entry);
     setState(() {});
   }
 
@@ -60,22 +62,27 @@ class _MetadataTabState extends State<MetadataTab> {
       }));
       return AvesExpansionTile(
         title: title,
-        children: [
+        children: data.isNotEmpty
-          Container(
+            ? [
-            alignment: AlignmentDirectional.topStart,
+                Padding(
-            padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+                  padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
-            child: InfoRowGroup(
+                  child: InfoRowGroup(
-              data,
+                    data,
-              maxValueLength: Constants.infoGroupMaxValueLength,
+                    maxValueLength: Constants.infoGroupMaxValueLength,
-            ),
+                  ),
-          )
+                )
-        ],
+              ]
+            : null,
       );
     }
 
     return ListView(
       padding: EdgeInsets.all(8),
       children: [
+        FutureBuilder<Map>(
+          future: _bitmapFactoryLoader,
+          builder: (context, snapshot) => builder(context, snapshot, 'Bitmap Factory'),
+        ),
         FutureBuilder<Map>(
           future: _contentResolverMetadataLoader,
           builder: (context, snapshot) => builder(context, snapshot, 'Content Resolver'),
@@ -88,6 +95,10 @@ class _MetadataTabState extends State<MetadataTab> {
           future: _mediaMetadataLoader,
           builder: (context, snapshot) => builder(context, snapshot, 'Media Metadata Retriever'),
         ),
+        FutureBuilder<Map>(
+          future: _metadataExtractorLoader,
+          builder: (context, snapshot) => builder(context, snapshot, 'Metadata Extractor'),
+        ),
       ],
     );
   }

lib/widgets/fullscreen/fullscreen_body.dart

@@ -10,6 +10,7 @@ import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/collection/collection_page.dart';
 import 'package:aves/widgets/common/action_delegates/entry_action_delegate.dart';
 import 'package:aves/widgets/fullscreen/image_page.dart';
+import 'package:aves/widgets/fullscreen/image_view.dart';
 import 'package:aves/widgets/fullscreen/info/info_page.dart';
 import 'package:aves/widgets/fullscreen/info/notifications.dart';
 import 'package:aves/widgets/fullscreen/overlay/bottom.dart';
@@ -52,6 +53,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
   EdgeInsets _frozenViewInsets, _frozenViewPadding;
   EntryActionDelegate _actionDelegate;
   final List<Tuple2<String, IjkMediaController>> _videoControllers = [];
+  final List<Tuple2<String, ValueNotifier<ViewState>>> _viewStateNotifiers = [];
 
   CollectionLens get collection => widget.collection;
 
@@ -97,7 +99,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
       collection: collection,
       showInfo: () => _goToVerticalPage(infoPage),
     );
-    _initVideoController();
+    _initViewStateControllers();
     _registerWidget(widget);
     WidgetsBinding.instance.addObserver(this);
     WidgetsBinding.instance.addPostFrameCallback((_) => _initOverlay());
@@ -154,7 +156,11 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
       },
       child: NotificationListener(
         onNotification: (notification) {
-          if (notification is FilterNotification) _goToCollection(notification.filter);
+          if (notification is FilterNotification) {
+            _goToCollection(notification.filter);
+          } else if (notification is ViewStateNotification) {
+            _updateViewState(notification.uri, notification.viewState);
+          }
           return false;
         },
         child: Stack(
@@ -169,6 +175,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
               onHorizontalPageChanged: _onHorizontalPageChanged,
               onImageTap: () => _overlayVisible.value = !_overlayVisible.value,
               onImagePageRequested: () => _goToVerticalPage(imagePage),
+              onViewDisposed: (uri) => _updateViewState(uri, null),
             ),
             _buildTopOverlay(),
             _buildBottomOverlay(),
@@ -178,11 +185,17 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
     );
   }
 
+  void _updateViewState(String uri, ViewState viewState) {
+    final viewStateNotifier = _viewStateNotifiers.firstWhere((kv) => kv.item1 == uri, orElse: () => null)?.item2;
+    viewStateNotifier?.value = viewState ?? ViewState.zero;
+  }
+
   Widget _buildTopOverlay() {
     final child = ValueListenableBuilder<ImageEntry>(
       valueListenable: _entryNotifier,
       builder: (context, entry, child) {
         if (entry == null) return SizedBox.shrink();
+        final viewStateNotifier = _viewStateNotifiers.firstWhere((kv) => kv.item1 == entry.uri, orElse: () => null)?.item2;
         return FullscreenTopOverlay(
           entry: entry,
           scale: _topOverlayScale,
@@ -190,6 +203,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
           viewInsets: _frozenViewInsets,
           viewPadding: _frozenViewPadding,
           onActionSelected: (action) => _actionDelegate.onActionSelected(context, entry, action),
+          viewStateNotifier: viewStateNotifier,
         );
       },
     );
@@ -324,7 +338,7 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
     if (_entryNotifier.value == newEntry) return;
     _entryNotifier.value = newEntry;
     _pauseVideoControllers();
-    _initVideoController();
+    _initViewStateControllers();
   }
 
   void _onLeave() {
@@ -381,28 +395,45 @@ class FullscreenBodyState extends State<FullscreenBody> with SingleTickerProvide
     }
   }
 
-  // video controller
+  // state controllers/monitors
 
-  void _pauseVideoControllers() => _videoControllers.forEach((e) => e.item2.pause());
+  void _initViewStateControllers() {
-
-  Future<void> _initVideoController() async {
     final entry = _entryNotifier.value;
-    if (entry == null || !entry.isVideo) return;
+    if (entry == null) return;
 
     final uri = entry.uri;
-    var controllerEntry = _videoControllers.firstWhere((kv) => kv.item1 == uri, orElse: () => null);
+    _initViewSpecificController<ValueNotifier<ViewState>>(
-    if (controllerEntry != null) {
+      uri,
-      _videoControllers.remove(controllerEntry);
+      _viewStateNotifiers,
-    } else {
+      () => ValueNotifier<ViewState>(ViewState.zero),
-      // do not set data source of IjkMediaController here
+      (_) => _.dispose(),
-      controllerEntry = Tuple2(uri, IjkMediaController());
+    );
-    }
+    if (entry.isVideo) {
-    _videoControllers.insert(0, controllerEntry);
+      _initViewSpecificController<IjkMediaController>(
-    while (_videoControllers.length > 3) {
+        uri,
-      _videoControllers.removeLast().item2.dispose();
+        _videoControllers,
+        () => IjkMediaController(),
+        (_) => _.dispose(),
+      );
     }
+
     setState(() {});
   }
+
+  void _initViewSpecificController<T>(String uri, List<Tuple2<String, T>> controllers, T Function() builder, void Function(T controller) disposer) {
+    var controller = controllers.firstWhere((kv) => kv.item1 == uri, orElse: () => null);
+    if (controller != null) {
+      controllers.remove(controller);
+    } else {
+      controller = Tuple2(uri, builder());
+    }
+    controllers.insert(0, controller);
+    while (controllers.length > 3) {
+      disposer?.call(controllers.removeLast().item2);
+    }
+  }
+
+  void _pauseVideoControllers() => _videoControllers.forEach((e) => e.item2.pause());
 }
 
 class FullscreenVerticalPageView extends StatefulWidget {
@@ -412,6 +443,7 @@ class FullscreenVerticalPageView extends StatefulWidget {
   final PageController horizontalPager, verticalPager;
   final void Function(int page) onVerticalPageChanged, onHorizontalPageChanged;
   final VoidCallback onImageTap, onImagePageRequested;
+  final void Function(String uri) onViewDisposed;
 
   const FullscreenVerticalPageView({
     @required this.collection,
@@ -423,6 +455,7 @@ class FullscreenVerticalPageView extends StatefulWidget {
     @required this.onHorizontalPageChanged,
     @required this.onImageTap,
     @required this.onImagePageRequested,
+    @required this.onViewDisposed,
   });
 
   @override
@@ -483,6 +516,7 @@ class _FullscreenVerticalPageViewState extends State<FullscreenVerticalPageView>
               onTap: widget.onImageTap,
               onPageChanged: widget.onHorizontalPageChanged,
               videoControllers: widget.videoControllers,
+              onViewDisposed: widget.onViewDisposed,
             )
           : SingleImagePage(
               entry: entry,

lib/widgets/fullscreen/image_page.dart

@@ -10,17 +10,17 @@ class MultiImagePage extends StatefulWidget {
   final CollectionLens collection;
   final PageController pageController;
   final ValueChanged<int> onPageChanged;
-  final ValueChanged<PhotoViewScaleState> onScaleChanged;
   final VoidCallback onTap;
   final List<Tuple2<String, IjkMediaController>> videoControllers;
+  final void Function(String uri) onViewDisposed;
 
   const MultiImagePage({
     this.collection,
     this.pageController,
     this.onPageChanged,
-    this.onScaleChanged,
     this.onTap,
     this.videoControllers,
+    this.onViewDisposed,
   });
 
   @override
@@ -49,9 +49,9 @@ class MultiImagePageState extends State<MultiImagePage> with AutomaticKeepAliveC
               key: Key('imageview'),
               entry: entry,
               heroTag: widget.collection.heroTag(entry),
-              onScaleChanged: widget.onScaleChanged,
               onTap: widget.onTap,
               videoControllers: widget.videoControllers,
+              onDisposed: () => widget.onViewDisposed?.call(entry.uri),
             ),
           );
         },
@@ -66,13 +66,11 @@ class MultiImagePageState extends State<MultiImagePage> with AutomaticKeepAliveC
 
 class SingleImagePage extends StatefulWidget {
   final ImageEntry entry;
-  final ValueChanged<PhotoViewScaleState> onScaleChanged;
   final VoidCallback onTap;
   final List<Tuple2<String, IjkMediaController>> videoControllers;
 
   const SingleImagePage({
     this.entry,
-    this.onScaleChanged,
     this.onTap,
     this.videoControllers,
   });
@@ -90,7 +88,6 @@ class SingleImagePageState extends State<SingleImagePage> with AutomaticKeepAliv
       axis: [Axis.vertical],
       child: ImageView(
         entry: widget.entry,
-        onScaleChanged: widget.onScaleChanged,
         onTap: widget.onTap,
         videoControllers: widget.videoControllers,
       ),

lib/widgets/fullscreen/image_view.dart

@@ -1,3 +1,5 @@
+import 'dart:async';
+
 import 'package:aves/model/image_entry.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/widgets/collection/empty.dart';
@@ -5,133 +7,221 @@ import 'package:aves/widgets/common/icons.dart';
 import 'package:aves/widgets/common/image_providers/thumbnail_provider.dart';
 import 'package:aves/widgets/common/image_providers/uri_image_provider.dart';
 import 'package:aves/widgets/common/image_providers/uri_picture_provider.dart';
+import 'package:aves/widgets/fullscreen/tiled_view.dart';
 import 'package:aves/widgets/fullscreen/video_view.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_ijkplayer/flutter_ijkplayer.dart';
 import 'package:flutter_svg/flutter_svg.dart';
 import 'package:photo_view/photo_view.dart';
+import 'package:provider/provider.dart';
 import 'package:tuple/tuple.dart';
 
-class ImageView extends StatelessWidget {
+class ImageView extends StatefulWidget {
   final ImageEntry entry;
   final Object heroTag;
-  final ValueChanged<PhotoViewScaleState> onScaleChanged;
   final VoidCallback onTap;
   final List<Tuple2<String, IjkMediaController>> videoControllers;
+  final VoidCallback onDisposed;
 
   const ImageView({
     Key key,
-    this.entry,
+    @required this.entry,
     this.heroTag,
-    this.onScaleChanged,
+    @required this.onTap,
-    this.onTap,
+    @required this.videoControllers,
-    this.videoControllers,
+    this.onDisposed,
   }) : super(key: key);
 
+  @override
+  _ImageViewState createState() => _ImageViewState();
+}
+
+class _ImageViewState extends State<ImageView> {
+  final PhotoViewController _photoViewController = PhotoViewController();
+  final ValueNotifier<ViewState> _viewStateNotifier = ValueNotifier<ViewState>(ViewState.zero);
+  StreamSubscription<PhotoViewControllerValue> _subscription;
+  Size _photoViewChildSize;
+
+  static const backgroundDecoration = BoxDecoration(color: Colors.transparent);
+  static const maxScale = 2.0;
+
+  ImageEntry get entry => widget.entry;
+
+  VoidCallback get onTap => widget.onTap;
+
+  @override
+  void initState() {
+    super.initState();
+    _subscription = _photoViewController.outputStateStream.listen(_onViewChanged);
+    if (entry.isVideo || (!entry.isSvg && entry.canDecode && useTile)) {
+      _photoViewChildSize = entry.displaySize;
+    }
+  }
+
+  @override
+  void dispose() {
+    _subscription.cancel();
+    _subscription = null;
+    widget.onDisposed?.call();
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
-    const backgroundDecoration = BoxDecoration(color: Colors.transparent);
-
-    // no hero for videos, as a typical video first frame is different from its thumbnail
-
-    if (entry.isVideo) {
-      final videoController = videoControllers.firstWhere((kv) => kv.item1 == entry.uri, orElse: () => null)?.item2;
-      return PhotoView.customChild(
-        child: videoController != null
-            ? AvesVideo(
-                entry: entry,
-                controller: videoController,
-              )
-            : SizedBox(),
-        backgroundDecoration: backgroundDecoration,
-        scaleStateChangedCallback: onScaleChanged,
-        minScale: PhotoViewComputedScale.contained,
-        initialScale: PhotoViewComputedScale.contained,
-        onTapUp: (tapContext, details, value) => onTap?.call(),
-      );
-    }
-
-    // if the hero tag is defined in the `loadingBuilder` and also set by the `heroAttributes`,
-    // the route transition becomes visible if the final is loaded before the hero animation is done.
-
-    // if the hero tag wraps the whole `PhotoView` and the `loadingBuilder` is not provided,
-    // there's a black frame between the hero animation and the final image, even when it's cached.
-
-    final fastThumbnailProvider = ThumbnailProvider(ThumbnailProviderKey.fromEntry(entry));
-    // this loading builder shows a transition image until the final image is ready
-    // if the image is already in the cache it will show the final image, otherwise the thumbnail
-    // in any case, we should use `Center` + `AspectRatio` + `Fill` so that the transition image
-    // appears as the final image with `PhotoViewComputedScale.contained` for `initialScale`
-    Widget loadingBuilder(BuildContext context, ImageProvider imageProvider) {
-      return Center(
-        child: AspectRatio(
-          // enforce original aspect ratio, as some thumbnails aspect ratios slightly differ
-          aspectRatio: entry.displayAspectRatio,
-          child: Image(
-            image: imageProvider,
-            fit: BoxFit.fill,
-          ),
-        ),
-      );
-    }
-
     Widget child;
-    if (entry.isSvg) {
+    if (entry.isVideo) {
-      final colorFilter = ColorFilter.mode(Color(settings.svgBackground), BlendMode.dstOver);
+      child = _buildVideoView();
-      child = PhotoView.customChild(
+    } else if (entry.isSvg) {
-        child: SvgPicture(
+      child = _buildSvgView();
-          UriPicture(
-            uri: entry.uri,
-            mimeType: entry.mimeType,
-          ),
-          placeholderBuilder: (context) => loadingBuilder(context, fastThumbnailProvider),
-          colorFilter: colorFilter,
-        ),
-        backgroundDecoration: backgroundDecoration,
-        scaleStateChangedCallback: onScaleChanged,
-        minScale: PhotoViewComputedScale.contained,
-        initialScale: PhotoViewComputedScale.contained,
-        onTapUp: (tapContext, details, value) => onTap?.call(),
-      );
     } else if (entry.canDecode) {
-      final uriImage = UriImage(
+      if (useTile) {
-        uri: entry.uri,
+        child = _buildTiledImageView();
-        mimeType: entry.mimeType,
+      } else {
-        rotationDegrees: entry.rotationDegrees,
+        child = _buildImageView();
-        isFlipped: entry.isFlipped,
+      }
-        expectedContentLength: entry.sizeBytes,
-      );
-      child = PhotoView(
-        // key includes size and orientation to refresh when the image is rotated
-        key: ValueKey('${entry.rotationDegrees}_${entry.isFlipped}_${entry.width}_${entry.height}_${entry.path}'),
-        imageProvider: uriImage,
-        // when the full image is ready, we use it in the `loadingBuilder`
-        // we still provide a `loadingBuilder` in that case to avoid a black frame after hero animation
-        loadingBuilder: (context, event) => loadingBuilder(
-          context,
-          imageCache.statusForKey(uriImage).keepAlive ? uriImage : fastThumbnailProvider,
-        ),
-        loadFailedChild: _buildError(),
-        backgroundDecoration: backgroundDecoration,
-        scaleStateChangedCallback: onScaleChanged,
-        minScale: PhotoViewComputedScale.contained,
-        initialScale: PhotoViewComputedScale.contained,
-        onTapUp: (tapContext, details, value) => onTap?.call(),
-        filterQuality: FilterQuality.low,
-      );
     } else {
       child = _buildError();
     }
 
-    return heroTag != null
+    // if the hero tag is defined in the `loadingBuilder` and also set by the `heroAttributes`,
+    // the route transition becomes visible if the final image is loaded before the hero animation is done.
+
+    // if the hero tag wraps the whole `PhotoView` and the `loadingBuilder` is not provided,
+    // there's a black frame between the hero animation and the final image, even when it's cached.
+
+    // no hero for videos, as a typical video first frame is different from its thumbnail
+    return widget.heroTag != null && !entry.isVideo
         ? Hero(
-            tag: heroTag,
+            tag: widget.heroTag,
             transitionOnUserGestures: true,
             child: child,
           )
         : child;
   }
 
+  // the images loaded by `PhotoView` cannot have a width or height larger than 8192
+  // so the reported offset and scale does not match expected values derived from the original dimensions
+  // besides, large images should be tiled to be memory-friendly
+  bool get useTile => entry.canTile && (entry.width > 4096 || entry.height > 4096);
+
+  ImageProvider get fastThumbnailProvider => ThumbnailProvider(ThumbnailProviderKey.fromEntry(entry));
+
+  // this loading builder shows a transition image until the final image is ready
+  // if the image is already in the cache it will show the final image, otherwise the thumbnail
+  // in any case, we should use `Center` + `AspectRatio` + `BoxFit.fill` so that the transition image
+  // appears as the final image with `PhotoViewComputedScale.contained` for `initialScale`
+  Widget _loadingBuilder(BuildContext context, ImageProvider imageProvider) {
+    return Center(
+      child: AspectRatio(
+        // enforce original aspect ratio, as some thumbnails aspect ratios slightly differ
+        aspectRatio: entry.displayAspectRatio,
+        child: Image(
+          image: imageProvider,
+          fit: BoxFit.fill,
+        ),
+      ),
+    );
+  }
+
+  Widget _buildImageView() {
+    final uriImage = UriImage(
+      uri: entry.uri,
+      mimeType: entry.mimeType,
+      rotationDegrees: entry.rotationDegrees,
+      isFlipped: entry.isFlipped,
+      expectedContentLength: entry.sizeBytes,
+    );
+    return PhotoView(
+      // key includes size and orientation to refresh when the image is rotated
+      key: ValueKey('${entry.rotationDegrees}_${entry.isFlipped}_${entry.width}_${entry.height}_${entry.path}'),
+      imageProvider: uriImage,
+      // when the full image is ready, we use it in the `loadingBuilder`
+      // we still provide a `loadingBuilder` in that case to avoid a black frame after hero animation
+      loadingBuilder: (context, event) => _loadingBuilder(
+        context,
+        imageCache.statusForKey(uriImage).keepAlive ? uriImage : fastThumbnailProvider,
+      ),
+      loadFailedChild: _buildError(),
+      backgroundDecoration: backgroundDecoration,
+      imageSizedCallback: (size) {
+        // do not directly update the `ViewState` notifier as this callback is called during build
+        _photoViewChildSize = size;
+      },
+      controller: _photoViewController,
+      maxScale: maxScale,
+      minScale: PhotoViewComputedScale.contained,
+      initialScale: PhotoViewComputedScale.contained,
+      onTapUp: (tapContext, details, value) => onTap?.call(),
+      filterQuality: FilterQuality.low,
+    );
+  }
+
+  Widget _buildTiledImageView() {
+    return PhotoView.customChild(
+      // key includes size and orientation to refresh when the image is rotated
+      key: ValueKey('${entry.rotationDegrees}_${entry.isFlipped}_${entry.width}_${entry.height}_${entry.path}'),
+      child: Selector<MediaQueryData, Size>(
+        selector: (context, mq) => mq.size,
+        builder: (context, mqSize, child) {
+          return TiledImageView(
+            entry: entry,
+            viewportSize: mqSize,
+            viewStateNotifier: _viewStateNotifier,
+            baseChild: _loadingBuilder(context, fastThumbnailProvider),
+            errorBuilder: (context, error, stackTrace) => _buildError(),
+          );
+        },
+      ),
+      childSize: entry.displaySize,
+      backgroundDecoration: backgroundDecoration,
+      controller: _photoViewController,
+      maxScale: maxScale,
+      minScale: PhotoViewComputedScale.contained,
+      initialScale: PhotoViewComputedScale.contained,
+      onTapUp: (tapContext, details, value) => onTap?.call(),
+      filterQuality: FilterQuality.low,
+    );
+  }
+
+  Widget _buildSvgView() {
+    final colorFilter = ColorFilter.mode(Color(settings.svgBackground), BlendMode.dstOver);
+    return PhotoView.customChild(
+      child: SvgPicture(
+        UriPicture(
+          uri: entry.uri,
+          mimeType: entry.mimeType,
+        ),
+        placeholderBuilder: (context) => _loadingBuilder(context, fastThumbnailProvider),
+        colorFilter: colorFilter,
+      ),
+      backgroundDecoration: backgroundDecoration,
+      controller: _photoViewController,
+      minScale: PhotoViewComputedScale.contained,
+      initialScale: PhotoViewComputedScale.contained,
+      onTapUp: (tapContext, details, value) => onTap?.call(),
+    );
+  }
+
+  Widget _buildVideoView() {
+    final videoController = widget.videoControllers.firstWhere((kv) => kv.item1 == entry.uri, orElse: () => null)?.item2;
+    return PhotoView.customChild(
+      child: videoController != null
+          ? AvesVideo(
+              entry: entry,
+              controller: videoController,
+            )
+          : SizedBox(),
+      childSize: entry.displaySize,
+      backgroundDecoration: backgroundDecoration,
+      controller: _photoViewController,
+      maxScale: maxScale,
+      minScale: PhotoViewComputedScale.contained,
+      initialScale: PhotoViewComputedScale.contained,
+      onTapUp: (tapContext, details, value) => onTap?.call(),
+    );
+  }
+
   Widget _buildError() => GestureDetector(
         onTap: () => onTap?.call(),
         // use a `Container` with a dummy color to make it expand
@@ -145,4 +235,37 @@ class ImageView extends StatelessWidget {
           ),
         ),
       );
+
+  void _onViewChanged(PhotoViewControllerValue v) {
+    final viewState = ViewState(v.position, v.scale, _photoViewChildSize);
+    _viewStateNotifier.value = viewState;
+    ViewStateNotification(entry.uri, viewState).dispatch(context);
+  }
+}
+
+class ViewState {
+  final Offset position;
+  final double scale;
+  final Size size;
+
+  static const ViewState zero = ViewState(Offset(0.0, 0.0), 0, null);
+
+  const ViewState(this.position, this.scale, this.size);
+
+  @override
+  String toString() {
+    return '$runtimeType#${shortHash(this)}{position=$position, scale=$scale, size=$size}';
+  }
+}
+
+class ViewStateNotification extends Notification {
+  final String uri;
+  final ViewState viewState;
+
+  const ViewStateNotification(this.uri, this.viewState);
+
+  @override
+  String toString() {
+    return '$runtimeType#${shortHash(this)}{uri=$uri, viewState=$viewState}';
+  }
 }

lib/widgets/fullscreen/info/basic_section.dart

@@ -29,7 +29,7 @@ class BasicSection extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final date = entry.bestDate;
-    final dateText = date != null ? '${DateFormat.yMMMd().format(date)} • ${DateFormat.Hm().format(date)}' : Constants.unknown;
+    final dateText = date != null ? '${DateFormat.yMMMd().format(date)} • ${DateFormat.Hm().format(date)}' : Constants.infoUnknown;
     final showMegaPixels = entry.isPhoto && entry.megaPixels != null && entry.megaPixels > 0;
     final resolutionText = '${entry.resolutionText}${showMegaPixels ? ' (${entry.megaPixels} MP)' : ''}';
 
@@ -37,12 +37,12 @@ class BasicSection extends StatelessWidget {
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
         InfoRowGroup({
-          'Title': entry.bestTitle ?? Constants.unknown,
+          'Title': entry.bestTitle ?? Constants.infoUnknown,
           'Date': dateText,
           if (entry.isVideo) ..._buildVideoRows(),
           if (!entry.isSvg) 'Resolution': resolutionText,
-          'Size': entry.sizeBytes != null ? formatFilesize(entry.sizeBytes) : Constants.unknown,
+          'Size': entry.sizeBytes != null ? formatFilesize(entry.sizeBytes) : Constants.infoUnknown,
-          'URI': entry.uri ?? Constants.unknown,
+          'URI': entry.uri ?? Constants.infoUnknown,
           if (entry.path != null) 'Path': entry.path,
         }),
         _buildChips(),

lib/widgets/fullscreen/info/maps/scalebar_utils.dart

@@ -1,17 +1,8 @@
 import 'dart:math';
 
+import 'package:aves/utils/math_utils.dart';
 import 'package:latlong/latlong.dart';
 
-const double piOver180 = PI / 180.0;
-
-double toDegrees(double radians) {
-  return radians / piOver180;
-}
-
-double toRadians(double degrees) {
-  return degrees * piOver180;
-}
-
 LatLng calculateEndingGlobalCoordinates(LatLng start, double startBearing, double distance) {
   var mSemiMajorAxis = 6378137.0; //WGS84 major axis
   var mSemiMinorAxis = (1.0 - 1.0 / 298.257223563) * 6378137.0;

lib/widgets/fullscreen/info/metadata_section.dart

@@ -5,6 +5,7 @@ import 'package:aves/services/metadata_service.dart';
 import 'package:aves/utils/constants.dart';
 import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_expansion_tile.dart';
+import 'package:aves/widgets/common/highlight_title.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:aves/widgets/fullscreen/info/common.dart';
 import 'package:aves/widgets/fullscreen/info/metadata_thumbnail.dart';
@@ -122,15 +123,15 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
   }
 
   Widget _buildDirTileWithTitle(_MetadataDirectory dir) {
+    if (dir.name == xmpDirectory) {
+      return _buildXmpDirTile(dir);
+    }
     Widget thumbnail;
     final prefixChildren = <Widget>[];
     switch (dir.name) {
       case exifThumbnailDirectory:
         thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.exif, entry: entry);
         break;
-      case xmpDirectory:
-        thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.xmp, entry: entry);
-        break;
       case mediaDirectory:
         thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.embedded, entry: entry);
         Widget builder(IconData data) => Padding(
@@ -153,14 +154,9 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
       title: dir.name,
       expandedNotifier: _expandedDirectoryNotifier,
       children: [
-        if (prefixChildren.isNotEmpty)
+        if (prefixChildren.isNotEmpty) Wrap(children: prefixChildren),
-          Align(
-            alignment: AlignmentDirectional.topStart,
-            child: Wrap(children: prefixChildren),
-          ),
         if (thumbnail != null) thumbnail,
-        Container(
+        Padding(
-          alignment: Alignment.topLeft,
           padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
           child: InfoRowGroup(dir.tags, maxValueLength: Constants.infoGroupMaxValueLength),
         ),
@@ -168,6 +164,42 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
     );
   }
 
+  Widget _buildXmpDirTile(_MetadataDirectory dir) {
+    final thumbnail = MetadataThumbnails(source: MetadataThumbnailSource.xmp, entry: entry);
+    final byNamespace = SplayTreeMap.of(
+      groupBy<MapEntry<String, String>, String>(dir.tags.entries, (kv) {
+        final fullKey = kv.key;
+        final i = fullKey.indexOf(':');
+        if (i == -1) return '';
+        return fullKey.substring(0, i);
+      }),
+      compareAsciiLowerCase,
+    );
+    return AvesExpansionTile(
+      title: dir.name,
+      expandedNotifier: _expandedDirectoryNotifier,
+      children: [
+        if (thumbnail != null) thumbnail,
+        Padding(
+          padding: EdgeInsets.only(left: 8, right: 8, bottom: 8),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: byNamespace.entries.expand((kv) {
+              final ns = kv.key;
+              final hasNamespace = ns.isNotEmpty;
+              final i = hasNamespace ? ns.length + 1 : 0;
+              final tags = Map.fromEntries(kv.value.map((kv) => MapEntry(kv.key.substring(i), kv.value)));
+              return [
+                if (hasNamespace) HighlightTitle(ns),
+                InfoRowGroup(tags, maxValueLength: Constants.infoGroupMaxValueLength),
+              ];
+            }).toList(),
+          ),
+        ),
+      ],
+    );
+  }
+
   void _onMetadataChanged() {
     _loadedMetadataUri.value = null;
     _metadata = [];
@@ -196,6 +228,7 @@ class _MetadataSectionSliverState extends State<MetadataSectionSliver> with Auto
       _metadata = [];
       _loadedMetadataUri.value = null;
     }
+    _expandedDirectoryNotifier.value = null;
   }
 
   @override

lib/widgets/fullscreen/overlay/bottom.dart

@@ -6,6 +6,7 @@ import 'package:aves/model/settings/coordinate_format.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/services/metadata_service.dart';
 import 'package:aves/utils/constants.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/fx/blurred.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:aves/widgets/fullscreen/overlay/common.dart';
@@ -150,25 +151,21 @@ class _FullscreenBottomOverlayContent extends AnimatedWidget {
             final positionTitle = [
               if (position != null) position,
               if (entry.bestTitle != null) entry.bestTitle,
-            ].join(' – ');
+            ].join(' • ');
             final hasShootingDetails = details != null && !details.isEmpty && settings.showOverlayShootingDetails;
             return Column(
               mainAxisSize: MainAxisSize.min,
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
                 if (positionTitle.isNotEmpty) Text(positionTitle, strutStyle: Constants.overflowStrutStyle),
-                if (entry.hasGps)
+                _buildSoloLocationRow(),
-                  Container(
-                    padding: EdgeInsets.only(top: _interRowPadding),
-                    child: _LocationRow(entry: entry),
-                  ),
                 if (twoColumns)
                   Padding(
                     padding: EdgeInsets.only(top: _interRowPadding),
                     child: Row(
                       children: [
                         Container(width: subRowWidth, child: _DateRow(entry)),
-                        if (hasShootingDetails) Container(width: subRowWidth, child: _ShootingRow(details)),
+                        _buildDuoShootingRow(subRowWidth, hasShootingDetails),
                       ],
                     ),
                   )
@@ -178,12 +175,7 @@ class _FullscreenBottomOverlayContent extends AnimatedWidget {
                     width: subRowWidth,
                     child: _DateRow(entry),
                   ),
-                  if (hasShootingDetails)
+                  _buildSoloShootingRow(subRowWidth, hasShootingDetails),
-                    Container(
-                      padding: EdgeInsets.only(top: _interRowPadding),
-                      width: subRowWidth,
-                      child: _ShootingRow(details),
-                    ),
                 ],
               ],
             );
@@ -192,6 +184,58 @@ class _FullscreenBottomOverlayContent extends AnimatedWidget {
       ),
     );
   }
+
+  Widget _buildSoloLocationRow() => AnimatedSwitcher(
+        duration: Durations.fullscreenOverlayChangeAnimation,
+        switchInCurve: Curves.easeInOutCubic,
+        switchOutCurve: Curves.easeInOutCubic,
+        transitionBuilder: _soloTransition,
+        child: entry.hasGps
+            ? Container(
+                padding: EdgeInsets.only(top: _interRowPadding),
+                child: _LocationRow(entry: entry),
+              )
+            : SizedBox.shrink(),
+      );
+
+  Widget _buildSoloShootingRow(double subRowWidth, bool hasShootingDetails) => AnimatedSwitcher(
+        duration: Durations.fullscreenOverlayChangeAnimation,
+        switchInCurve: Curves.easeInOutCubic,
+        switchOutCurve: Curves.easeInOutCubic,
+        transitionBuilder: _soloTransition,
+        child: hasShootingDetails
+            ? Container(
+                padding: EdgeInsets.only(top: _interRowPadding),
+                width: subRowWidth,
+                child: _ShootingRow(details),
+              )
+            : SizedBox.shrink(),
+      );
+
+  Widget _buildDuoShootingRow(double subRowWidth, bool hasShootingDetails) => AnimatedSwitcher(
+        duration: Durations.fullscreenOverlayChangeAnimation,
+        switchInCurve: Curves.easeInOutCubic,
+        switchOutCurve: Curves.easeInOutCubic,
+        transitionBuilder: (child, animation) => FadeTransition(
+          opacity: animation,
+          child: child,
+        ),
+        child: hasShootingDetails
+            ? Container(
+                width: subRowWidth,
+                child: _ShootingRow(details),
+              )
+            : SizedBox.shrink(),
+      );
+
+  static Widget _soloTransition(Widget child, Animation<double> animation) => FadeTransition(
+        opacity: animation,
+        child: SizeTransition(
+          axisAlignment: 1,
+          sizeFactor: animation,
+          child: child,
+        ),
+      );
 }
 
 class _LocationRow extends AnimatedWidget {
@@ -228,7 +272,7 @@ class _DateRow extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final date = entry.bestDate;
-    final dateText = date != null ? '${DateFormat.yMMMd().format(date)} • ${DateFormat.Hm().format(date)}' : Constants.unknown;
+    final dateText = date != null ? '${DateFormat.yMMMd().format(date)} • ${DateFormat.Hm().format(date)}' : Constants.overlayUnknown;
     return Row(
       children: [
         DecoratedIcon(AIcons.date, shadows: [Constants.embossShadow], size: _iconSize),
@@ -251,10 +295,10 @@ class _ShootingRow extends StatelessWidget {
       children: [
         DecoratedIcon(AIcons.shooting, shadows: [Constants.embossShadow], size: _iconSize),
         SizedBox(width: _iconPadding),
-        Expanded(child: Text(details.aperture, strutStyle: Constants.overflowStrutStyle)),
+        Expanded(child: Text(details.aperture ?? Constants.overlayUnknown, strutStyle: Constants.overflowStrutStyle)),
-        Expanded(child: Text(details.exposureTime, strutStyle: Constants.overflowStrutStyle)),
+        Expanded(child: Text(details.exposureTime ?? Constants.overlayUnknown, strutStyle: Constants.overflowStrutStyle)),
-        Expanded(child: Text(details.focalLength, strutStyle: Constants.overflowStrutStyle)),
+        Expanded(child: Text(details.focalLength ?? Constants.overlayUnknown, strutStyle: Constants.overflowStrutStyle)),
-        Expanded(child: Text(details.iso, strutStyle: Constants.overflowStrutStyle)),
+        Expanded(child: Text(details.iso ?? Constants.overlayUnknown, strutStyle: Constants.overflowStrutStyle)),
       ],
     );
   }

lib/widgets/fullscreen/overlay/minimap.dart

@@ -0,0 +1,104 @@
+import 'dart:math';
+
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/widgets/fullscreen/image_view.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+class Minimap extends StatelessWidget {
+  final ImageEntry entry;
+  final ValueNotifier<ViewState> viewStateNotifier;
+  final Size size;
+
+  static const defaultSize = Size(96, 96);
+
+  const Minimap({
+    @required this.entry,
+    @required this.viewStateNotifier,
+    this.size = defaultSize,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Selector<MediaQueryData, Size>(
+        selector: (context, mq) => mq.size,
+        builder: (context, mqSize, child) {
+          return AnimatedBuilder(
+              animation: viewStateNotifier,
+              builder: (context, child) {
+                final viewState = viewStateNotifier.value;
+                return CustomPaint(
+                  painter: MinimapPainter(
+                    viewportSize: mqSize,
+                    entrySize: viewState.size ?? entry.displaySize,
+                    viewCenterOffset: viewState.position,
+                    viewScale: viewState.scale,
+                    minimapBorderColor: Colors.white30,
+                  ),
+                  size: size,
+                );
+              });
+        });
+  }
+}
+
+class MinimapPainter extends CustomPainter {
+  final Size entrySize, viewportSize;
+  final Offset viewCenterOffset;
+  final double viewScale;
+  final Color minimapBorderColor, viewportBorderColor;
+
+  const MinimapPainter({
+    @required this.viewportSize,
+    @required this.entrySize,
+    @required this.viewCenterOffset,
+    @required this.viewScale,
+    this.minimapBorderColor = Colors.white,
+    this.viewportBorderColor = Colors.white,
+  });
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final viewSize = entrySize * viewScale;
+    if (viewSize.isEmpty) return;
+
+    // hide minimap when image is in full view
+    if (viewportSize + Offset(precisionErrorTolerance, precisionErrorTolerance) >= viewSize) return;
+
+    final canvasScale = size.longestSide / viewSize.longestSide;
+    final scaledEntrySize = viewSize * canvasScale;
+    final scaledViewportSize = viewportSize * canvasScale;
+
+    final entryRect = Rect.fromCenter(
+      center: size.center(Offset.zero),
+      width: scaledEntrySize.width,
+      height: scaledEntrySize.height,
+    );
+    final viewportRect = Rect.fromCenter(
+      center: size.center(Offset.zero) - viewCenterOffset * canvasScale,
+      width: min(scaledEntrySize.width, scaledViewportSize.width),
+      height: min(scaledEntrySize.height, scaledViewportSize.height),
+    );
+
+    canvas.translate((entryRect.width - size.width) / 2, (entryRect.height - size.height) / 2);
+
+    final fill = Paint()
+      ..style = PaintingStyle.fill
+      ..color = Color(0x33000000);
+    final minimapStroke = Paint()
+      ..style = PaintingStyle.stroke
+      ..color = minimapBorderColor;
+    final viewportStroke = Paint()
+      ..style = PaintingStyle.stroke
+      ..color = viewportBorderColor;
+
+    canvas.drawRect(viewportRect, fill);
+    canvas.drawRect(entryRect, fill);
+    canvas.drawRect(entryRect, minimapStroke);
+    canvas.drawRect(viewportRect, viewportStroke);
+  }
+
+  @override
+  bool shouldRepaint(CustomPainter oldDelegate) => true;
+}

lib/widgets/fullscreen/overlay/top.dart

@@ -2,11 +2,14 @@ import 'dart:math';
 
 import 'package:aves/model/favourite_repo.dart';
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/model/settings/settings.dart';
 import 'package:aves/widgets/common/entry_actions.dart';
 import 'package:aves/widgets/common/fx/sweeper.dart';
 import 'package:aves/widgets/common/icons.dart';
 import 'package:aves/widgets/common/menu_row.dart';
+import 'package:aves/widgets/fullscreen/image_view.dart';
 import 'package:aves/widgets/fullscreen/overlay/common.dart';
+import 'package:aves/widgets/fullscreen/overlay/minimap.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
@@ -18,6 +21,7 @@ class FullscreenTopOverlay extends StatelessWidget {
   final EdgeInsets viewInsets, viewPadding;
   final Function(EntryAction value) onActionSelected;
   final bool canToggleFavourite;
+  final ValueNotifier<ViewState> viewStateNotifier;
 
   static const double padding = 8;
 
@@ -33,6 +37,7 @@ class FullscreenTopOverlay extends StatelessWidget {
     @required this.viewInsets,
     @required this.viewPadding,
     @required this.onActionSelected,
+    this.viewStateNotifier,
   }) : super(key: key);
 
   @override
@@ -58,8 +63,7 @@ class FullscreenTopOverlay extends StatelessWidget {
             ].where(_canDo).take(quickActionCount).toList();
             final inAppActions = EntryActions.inApp.where((action) => !quickActions.contains(action)).where(_canDo).toList();
             final externalAppActions = EntryActions.externalApp.where(_canDo).toList();
-
+            final buttonRow = _TopOverlayRow(
-            return _TopOverlayRow(
               quickActions: quickActions,
               inAppActions: inAppActions,
               externalAppActions: externalAppActions,
@@ -67,6 +71,23 @@ class FullscreenTopOverlay extends StatelessWidget {
               entry: entry,
               onActionSelected: onActionSelected,
             );
+
+            return settings.showOverlayMinimap && viewStateNotifier != null
+                ? Column(
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      buttonRow,
+                      SizedBox(height: 8),
+                      FadeTransition(
+                        opacity: scale,
+                        child: Minimap(
+                          entry: entry,
+                          viewStateNotifier: viewStateNotifier,
+                        ),
+                      )
+                    ],
+                  )
+                : buttonRow;
           },
         ),
       ),

lib/widgets/fullscreen/tiled_view.dart

@@ -0,0 +1,279 @@
+import 'dart:math';
+
+import 'package:aves/model/image_entry.dart';
+import 'package:aves/utils/math_utils.dart';
+import 'package:aves/widgets/common/image_providers/region_provider.dart';
+import 'package:aves/widgets/fullscreen/image_view.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+class TiledImageView extends StatefulWidget {
+  final ImageEntry entry;
+  final Size viewportSize;
+  final ValueNotifier<ViewState> viewStateNotifier;
+  final Widget baseChild;
+  final ImageErrorWidgetBuilder errorBuilder;
+
+  const TiledImageView({
+    @required this.entry,
+    @required this.viewportSize,
+    @required this.viewStateNotifier,
+    @required this.baseChild,
+    @required this.errorBuilder,
+  });
+
+  @override
+  _TiledImageViewState createState() => _TiledImageViewState();
+}
+
+class _TiledImageViewState extends State<TiledImageView> {
+  double _tileSide, _initialScale;
+  int _maxSampleSize;
+  Matrix4 _transform;
+
+  ImageEntry get entry => widget.entry;
+
+  Size get viewportSize => widget.viewportSize;
+
+  ValueNotifier<ViewState> get viewStateNotifier => widget.viewStateNotifier;
+
+  // magic number used to derive sample size from scale
+  static const scaleFactor = 2.0;
+
+  @override
+  void initState() {
+    super.initState();
+    _init();
+  }
+
+  @override
+  void didUpdateWidget(TiledImageView oldWidget) {
+    super.didUpdateWidget(oldWidget);
+
+    if (oldWidget.viewportSize != widget.viewportSize || oldWidget.entry.displaySize != widget.entry.displaySize) {
+      _init();
+    }
+  }
+
+  void _init() {
+    _tileSide = viewportSize.shortestSide * scaleFactor;
+    _initialScale = min(viewportSize.width / entry.displaySize.width, viewportSize.height / entry.displaySize.height);
+    _maxSampleSize = _sampleSizeForScale(_initialScale);
+
+    final rotationDegrees = entry.rotationDegrees;
+    final isFlipped = entry.isFlipped;
+    _transform = null;
+    if (rotationDegrees != 0 || isFlipped) {
+      _transform = Matrix4.identity()
+        ..translate(entry.width / 2.0, entry.height / 2.0)
+        ..scale(isFlipped ? -1.0 : 1.0, 1.0, 1.0)
+        ..rotateZ(-toRadians(rotationDegrees.toDouble()))
+        ..translate(-entry.displaySize.width / 2.0, -entry.displaySize.height / 2.0);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if (viewStateNotifier == null) return SizedBox.shrink();
+
+    final displayWidth = entry.displaySize.width.round();
+    final displayHeight = entry.displaySize.height.round();
+
+    return AnimatedBuilder(
+        animation: viewStateNotifier,
+        builder: (context, child) {
+          final viewState = viewStateNotifier.value;
+          var scale = viewState.scale;
+          if (scale == 0.0) {
+            // for initial scale as `PhotoViewComputedScale.contained`
+            scale = _initialScale;
+          }
+
+          final centerOffset = viewState.position;
+          final viewOrigin = Offset(
+            ((displayWidth * scale - viewportSize.width) / 2 - centerOffset.dx),
+            ((displayHeight * scale - viewportSize.height) / 2 - centerOffset.dy),
+          );
+          final viewRect = viewOrigin & viewportSize;
+
+          final tiles = <RegionTile>[];
+          var minSampleSize = min(_sampleSizeForScale(scale), _maxSampleSize);
+          for (var sampleSize = _maxSampleSize; sampleSize >= minSampleSize; sampleSize = (sampleSize / 2).floor()) {
+            // for the largest sample size (matching the initial scale), the whole image is in view
+            // so we subsample the whole image instead of splitting it in tiles
+            final useTiles = sampleSize != _maxSampleSize;
+            final regionSide = (_tileSide * sampleSize).round();
+            final layerRegionWidth = useTiles ? regionSide : displayWidth;
+            final layerRegionHeight = useTiles ? regionSide : displayHeight;
+            for (var x = 0; x < displayWidth; x += layerRegionWidth) {
+              for (var y = 0; y < displayHeight; y += layerRegionHeight) {
+                final nextX = x + layerRegionWidth;
+                final nextY = y + layerRegionHeight;
+                final thisRegionWidth = layerRegionWidth - (nextX >= displayWidth ? nextX - displayWidth : 0);
+                final thisRegionHeight = layerRegionHeight - (nextY >= displayHeight ? nextY - displayHeight : 0);
+                final tileRect = Rect.fromLTWH(x * scale, y * scale, thisRegionWidth * scale, thisRegionHeight * scale);
+
+                // only build visible tiles
+                if (viewRect.overlaps(tileRect)) {
+                  Rectangle<int> regionRect;
+
+                  if (_transform != null) {
+                    // apply EXIF orientation
+                    final regionRectDouble = Rect.fromLTWH(x.toDouble(), y.toDouble(), thisRegionWidth.toDouble(), thisRegionHeight.toDouble());
+                    final tl = MatrixUtils.transformPoint(_transform, regionRectDouble.topLeft);
+                    final br = MatrixUtils.transformPoint(_transform, regionRectDouble.bottomRight);
+                    regionRect = Rectangle<int>.fromPoints(
+                      Point<int>(tl.dx.round(), tl.dy.round()),
+                      Point<int>(br.dx.round(), br.dy.round()),
+                    );
+                  } else {
+                    regionRect = Rectangle<int>(x, y, thisRegionWidth, thisRegionHeight);
+                  }
+
+                  tiles.add(RegionTile(
+                    entry: entry,
+                    tileRect: tileRect,
+                    regionRect: regionRect,
+                    sampleSize: sampleSize,
+                  ));
+                }
+              }
+            }
+          }
+
+          return Stack(
+            alignment: Alignment.center,
+            children: [
+              SizedBox(
+                width: displayWidth * scale,
+                height: displayHeight * scale,
+                child: widget.baseChild,
+              ),
+              ...tiles,
+            ],
+          );
+        });
+  }
+
+  int _sampleSizeForScale(double scale) {
+    var sample = 0;
+    if (0 < scale && scale < 1) {
+      sample = highestPowerOf2((1 / scale) / scaleFactor);
+    }
+    return max<int>(1, sample);
+  }
+}
+
+class RegionTile extends StatefulWidget {
+  final ImageEntry entry;
+
+  // `tileRect` uses Flutter view coordinates
+  // `regionRect` uses the raw image pixel coordinates
+  final Rect tileRect;
+  final Rectangle<int> regionRect;
+  final int sampleSize;
+
+  const RegionTile({
+    @required this.entry,
+    @required this.tileRect,
+    @required this.regionRect,
+    @required this.sampleSize,
+  });
+
+  @override
+  _RegionTileState createState() => _RegionTileState();
+}
+
+class _RegionTileState extends State<RegionTile> {
+  RegionProvider _provider;
+
+  ImageEntry get entry => widget.entry;
+
+  @override
+  void initState() {
+    super.initState();
+    _registerWidget(widget);
+  }
+
+  @override
+  void didUpdateWidget(RegionTile oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (oldWidget.entry != widget.entry || oldWidget.tileRect != widget.tileRect || oldWidget.sampleSize != widget.sampleSize || oldWidget.sampleSize != widget.sampleSize) {
+      _unregisterWidget(oldWidget);
+      _registerWidget(widget);
+    }
+  }
+
+  @override
+  void dispose() {
+    _unregisterWidget(widget);
+    super.dispose();
+  }
+
+  void _registerWidget(RegionTile widget) {
+    _initProvider();
+  }
+
+  void _unregisterWidget(RegionTile widget) {
+    _pauseProvider();
+  }
+
+  void _initProvider() {
+    if (!entry.canDecode) return;
+
+    _provider = RegionProvider(RegionProviderKey.fromEntry(
+      entry,
+      sampleSize: widget.sampleSize,
+      rect: widget.regionRect,
+    ));
+  }
+
+  void _pauseProvider() => _provider?.pause();
+
+  @override
+  Widget build(BuildContext context) {
+    final tileRect = widget.tileRect;
+
+    Widget child = Image(
+      image: _provider,
+      width: tileRect.width,
+      height: tileRect.height,
+      fit: BoxFit.fill,
+    );
+
+    // apply EXIF orientation
+    final quarterTurns = entry.rotationDegrees ~/ 90;
+    if (entry.isFlipped) {
+      final rotated = quarterTurns % 2 != 0;
+      final w = (rotated ? tileRect.height : tileRect.width) / 2.0;
+      final h = (rotated ? tileRect.width : tileRect.height) / 2.0;
+      final flipper = Matrix4.identity()
+        ..translate(w, h)
+        ..scale(-1.0, 1.0, 1.0)
+        ..translate(-w, -h);
+      child = Transform(
+        transform: flipper,
+        child: child,
+      );
+    }
+    if (quarterTurns != 0) {
+      child = RotatedBox(
+        quarterTurns: quarterTurns,
+        child: child,
+      );
+    }
+
+    return Positioned.fromRect(
+      rect: tileRect,
+      child: child,
+    );
+  }
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    properties.add(IntProperty('contentId', widget.entry.contentId));
+    properties.add(IntProperty('sampleSize', widget.sampleSize));
+    properties.add(DiagnosticsProperty<Rectangle<int>>('regionRect', widget.regionRect));
+  }
+}

lib/widgets/settings/settings_page.dart

@@ -3,6 +3,7 @@ import 'package:aves/model/settings/home_page.dart';
 import 'package:aves/model/settings/screen_on.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/utils/constants.dart';
+import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_expansion_tile.dart';
 import 'package:aves/widgets/common/aves_selection_dialog.dart';
 import 'package:aves/widgets/common/data_providers/media_query_data_provider.dart';
@@ -10,6 +11,7 @@ import 'package:aves/widgets/common/highlight_title.dart';
 import 'package:aves/widgets/settings/access_grants.dart';
 import 'package:aves/widgets/settings/svg_background.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_staggered_animations/flutter_staggered_animations.dart';
 import 'package:provider/provider.dart';
 
 class SettingsPage extends StatefulWidget {
@@ -25,24 +27,33 @@ class _SettingsPageState extends State<SettingsPage> {
   @override
   Widget build(BuildContext context) {
     return MediaQueryDataProvider(
-      child: DefaultTabController(
+      child: Scaffold(
-        length: 4,
+        appBar: AppBar(
-        child: Scaffold(
+          title: Text('Settings'),
-          appBar: AppBar(
+        ),
-            title: Text('Settings'),
+        body: SafeArea(
-          ),
+          child: Consumer<Settings>(
-          body: SafeArea(
+            builder: (context, settings, child) => AnimationLimiter(
-            child: Consumer<Settings>(
+              child: ListView(
-              builder: (context, settings, child) => ListView(
                 padding: EdgeInsets.all(8),
-                children: [
+                children: AnimationConfiguration.toStaggeredList(
-                  _buildNavigationSection(context),
+                  duration: Durations.staggeredAnimation,
-                  _buildDisplaySection(context),
+                  delay: Durations.staggeredAnimationDelay,
-                  _buildThumbnailsSection(context),
+                  childAnimationBuilder: (child) => SlideAnimation(
-                  _buildViewerSection(context),
+                    verticalOffset: 50.0,
-                  _buildSearchSection(context),
+                    child: FadeInAnimation(
-                  _buildPrivacySection(context),
+                      child: child,
-                ],
+                    ),
+                  ),
+                  children: [
+                    _buildNavigationSection(context),
+                    _buildDisplaySection(context),
+                    _buildThumbnailsSection(context),
+                    _buildViewerSection(context),
+                    _buildSearchSection(context),
+                    _buildPrivacySection(context),
+                  ],
+                ),
               ),
             ),
           ),
@@ -163,6 +174,11 @@ class _SettingsPageState extends State<SettingsPage> {
       title: 'Viewer',
       expandedNotifier: _expandedNotifier,
       children: [
+        SwitchListTile(
+          value: settings.showOverlayMinimap,
+          onChanged: (v) => settings.showOverlayMinimap = v,
+          title: Text('Show minimap'),
+        ),
         SwitchListTile(
           value: settings.showOverlayShootingDetails,
           onChanged: (v) => settings.showOverlayShootingDetails = v,
@@ -201,9 +217,8 @@ class _SettingsPageState extends State<SettingsPage> {
           onChanged: (v) => settings.isCrashlyticsEnabled = v,
           title: Text('Allow anonymous analytics and crash reporting'),
         ),
-        Container(
+        Padding(
-          alignment: AlignmentDirectional.topStart,
+          padding: EdgeInsets.only(top: 8, bottom: 16),
-          padding: EdgeInsets.only(bottom: 16),
           child: GrantedDirectories(),
         ),
       ],

lib/widgets/stats/filter_table.dart

@@ -2,6 +2,7 @@ import 'package:aves/model/filters/filters.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/model/source/collection_lens.dart';
 import 'package:aves/utils/color_utils.dart';
+import 'package:aves/utils/constants.dart';
 import 'package:aves/widgets/collection/collection_page.dart';
 import 'package:aves/widgets/common/aves_filter_chip.dart';
 import 'package:collection/collection.dart';
@@ -50,7 +51,10 @@ class FilterTable extends StatelessWidget {
               return TableRow(
                 children: [
                   Container(
-                    padding: EdgeInsets.only(bottom: 8),
+                    // the `Table` `border` property paints on the cells and does not add margins,
+                    // so we define margins here instead, but they should be symmetric
+                    // to keep all cells vertically aligned on the center/middle
+                    margin: EdgeInsets.symmetric(vertical: 4),
                     alignment: AlignmentDirectional.centerStart,
                     child: AvesFilterChip(
                       filter: filter,
@@ -65,7 +69,10 @@ class FilterTable extends StatelessWidget {
                       progressColor: stringToColor(label),
                       animation: true,
                       padding: EdgeInsets.symmetric(horizontal: lineHeight),
-                      center: Text(NumberFormat.percentPattern().format(percent)),
+                      center: Text(
+                        NumberFormat.percentPattern().format(percent),
+                        style: TextStyle(shadows: [Constants.embossShadow]),
+                      ),
                     ),
                   Text(
                     '$count',

lib/widgets/stats/stats.dart

@@ -5,6 +5,7 @@ import 'package:aves/model/filters/location.dart';
 import 'package:aves/model/filters/mime.dart';
 import 'package:aves/model/filters/tag.dart';
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/model/mime_types.dart';
 import 'package:aves/model/settings/settings.dart';
 import 'package:aves/model/source/collection_lens.dart';
 import 'package:aves/utils/color_utils.dart';
@@ -90,7 +91,10 @@ class StatsPage extends StatelessWidget {
               leading: Icon(AIcons.location),
               // right padding to match leading, so that inside label is aligned with outside label below
               padding: EdgeInsets.symmetric(horizontal: lineHeight) + EdgeInsets.only(right: 24),
-              center: Text(NumberFormat.percentPattern().format(withGpsPercent)),
+              center: Text(
+                NumberFormat.percentPattern().format(withGpsPercent),
+                style: TextStyle(shadows: [Constants.embossShadow]),
+              ),
             ),
             SizedBox(height: 8),
             Text('${withGps.length} ${Intl.plural(withGps.length, one: 'item', other: 'items')} with location'),
@@ -257,7 +261,7 @@ class EntryByMimeDatum {
   EntryByMimeDatum({
     @required this.mimeType,
     @required this.entryCount,
-  }) : displayText = MimeFilter.displayType(mimeType);
+  }) : displayText = MimeTypes.displayType(mimeType);
 
   Color get color => stringToColor(displayText);
 

lib/widgets/welcome_page.dart

@@ -3,6 +3,7 @@ import 'package:aves/utils/durations.dart';
 import 'package:aves/widgets/common/aves_logo.dart';
 import 'package:aves/widgets/common/labeled_checkbox.dart';
 import 'package:aves/widgets/home_page.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_markdown/flutter_markdown.dart';
@@ -24,6 +25,9 @@ class _WelcomePageState extends State<WelcomePage> {
   void initState() {
     super.initState();
     _termsLoader = rootBundle.loadString('assets/terms.md');
+    if (!kReleaseMode) {
+      settings.isCrashlyticsEnabled = false;
+    }
   }
 
   @override
@@ -167,9 +171,8 @@ class _WelcomePageState extends State<WelcomePage> {
     );
   }
 
-  // workaround to handle `Flexible` widgets,
+  // as of flutter_staggered_animations v0.1.2, `AnimationConfiguration.toStaggeredList` does not handle `Flexible` widgets
-  // because `AnimationConfiguration.toStaggeredList` does not,
+  // so we use this workaround instead
-  // as of flutter_staggered_animations v0.1.2,
   static List<Widget> _toStaggeredList({
     Duration duration,
     Duration delay,

pubspec.lock

@@ -14,7 +14,7 @@ packages:
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.40.5"
+    version: "0.40.6"
   ansicolor:
     dependency: transitive
     description:
@@ -133,7 +133,7 @@ packages:
       name: coverage
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.14.1"
+    version: "0.14.2"
   crypto:
     dependency: transitive
     description:
@@ -169,7 +169,7 @@ packages:
     description:
       path: "."
       ref: HEAD
-      resolved-ref: edb6b11bb448fc2f30e566a20605b37093503176
+      resolved-ref: "51fe2b12588356fade82ce65daef5482beed54e7"
       url: "git://github.com/deckerst/expansion_tile_card.git"
     source: git
     version: "1.0.3"
@@ -207,7 +207,7 @@ packages:
       name: firebase_analytics
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.1.0"
+    version: "6.2.0"
   firebase_analytics_platform_interface:
     dependency: transitive
     description:
@@ -228,7 +228,7 @@ packages:
       name: firebase_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.5.1"
+    version: "0.5.2"
   firebase_core_platform_interface:
     dependency: transitive
     description:
@@ -242,21 +242,21 @@ packages:
       name: firebase_core_web
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.0"
+    version: "0.2.1"
   firebase_crashlytics:
     dependency: "direct main"
     description:
       name: firebase_crashlytics
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.2"
+    version: "0.2.3"
   firebase_crashlytics_platform_interface:
     dependency: transitive
     description:
       name: firebase_crashlytics_platform_interface
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
+    version: "1.1.3"
   flushbar:
     dependency: "direct main"
     description:
@@ -381,7 +381,7 @@ packages:
       name: google_maps_flutter
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.0.6"
   google_maps_flutter_platform_interface:
     dependency: transitive
     description:
@@ -416,7 +416,7 @@ packages:
       name: image
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.18"
+    version: "2.1.19"
   intl:
     dependency: "direct main"
     description:
@@ -563,7 +563,7 @@ packages:
       name: package_info
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.4.3"
+    version: "0.4.3+2"
   palette_generator:
     dependency: "direct main"
     description:
@@ -598,7 +598,7 @@ packages:
       name: path_provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.22"
+    version: "1.6.24"
   path_provider_linux:
     dependency: transitive
     description:
@@ -612,21 +612,21 @@ packages:
       name: path_provider_macos
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.4+4"
+    version: "0.0.4+6"
   path_provider_platform_interface:
     dependency: transitive
     description:
       name: path_provider_platform_interface
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.3"
+    version: "1.0.4"
   path_provider_windows:
     dependency: transitive
     description:
       name: path_provider_windows
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.4+1"
+    version: "0.0.4+3"
   pdf:
     dependency: "direct main"
     description:
@@ -674,7 +674,7 @@ packages:
     description:
       path: "."
       ref: HEAD
-      resolved-ref: "79a3c20ee7f01e6ffb71464000c2ca8f1e28ec44"
+      resolved-ref: aa6400bbc85bf6ce953c4609d126796cdb4ca3c2
       url: "git://github.com/deckerst/photo_view.git"
     source: git
     version: "0.9.2"
@@ -712,7 +712,7 @@ packages:
       name: printing
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.7.0"
+    version: "3.7.1"
   process:
     dependency: transitive
     description:
@@ -754,7 +754,7 @@ packages:
       name: quiver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.4+1"
+    version: "2.1.5"
   rxdart:
     dependency: transitive
     description:
@@ -775,21 +775,21 @@ packages:
       name: shared_preferences
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.5.12+2"
+    version: "0.5.12+4"
   shared_preferences_linux:
     dependency: transitive
     description:
       name: shared_preferences_linux
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.2+2"
+    version: "0.0.2+4"
   shared_preferences_macos:
     dependency: transitive
     description:
       name: shared_preferences_macos
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.1+10"
+    version: "0.0.1+11"
   shared_preferences_platform_interface:
     dependency: transitive
     description:
@@ -810,7 +810,7 @@ packages:
       name: shared_preferences_windows
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.1+1"
+    version: "0.0.1+3"
   shelf:
     dependency: transitive
     description:
@@ -990,21 +990,21 @@ packages:
       name: url_launcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.7.8"
+    version: "5.7.10"
   url_launcher_linux:
     dependency: transitive
     description:
       name: url_launcher_linux
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.1+3"
+    version: "0.0.1+4"
   url_launcher_macos:
     dependency: transitive
     description:
       name: url_launcher_macos
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.1+8"
+    version: "0.0.1+9"
   url_launcher_platform_interface:
     dependency: transitive
     description:
@@ -1018,14 +1018,14 @@ packages:
       name: url_launcher_web
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.5"
+    version: "0.1.5+1"
   url_launcher_windows:
     dependency: transitive
     description:
       name: url_launcher_windows
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.1+1"
+    version: "0.0.1+3"
   utf:
     dependency: transitive
     description:
@@ -1060,7 +1060,7 @@ packages:
       name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.4.0"
+    version: "5.5.0"
   vm_service_client:
     dependency: transitive
     description:
@@ -1095,7 +1095,7 @@ packages:
       name: webkit_inspection_protocol
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.7.3"
+    version: "0.7.4"
   win32:
     dependency: transitive
     description:

pubspec.yaml

@@ -15,7 +15,11 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
 # Read more about iOS versioning at
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
-version: 1.2.5+31
+version: 1.2.6+32
+
+# brendan-duncan/image (as of v2.1.19):
+# - does not support TIFF with JPEG compression (issue #184)
+# - TIFF tile decoding is not public (issue #258)
 
 # video_player (as of v0.10.8+2, backed by ExoPlayer):
 # - does not support content URIs (by default, but trivial by fork)
@@ -33,6 +37,9 @@ version: 1.2.5+31
 # - does not support AC3 (by default, but possible by custom build)
 # - can play if only the video or audio stream is supported
 
+environment:
+  sdk: ">=2.7.0 <3.0.0"
+
 dependencies:
   flutter:
     sdk: flutter

test/utils/time_utils_test.dart

@@ -0,0 +1,18 @@
+import 'package:test/test.dart';
+import 'package:aves/utils/time_utils.dart';
+
+void main() {
+  test('Comparison extension functions', () {
+    expect(DateTime(1593, 7, 8).isAtSameYearAs(null), false);
+    expect(DateTime(1903, 9, 25).isAtSameYearAs(DateTime(1970, 2, 25)), false);
+    expect(DateTime(1929, 3, 22).isAtSameYearAs(DateTime(1929, 3, 22)), true);
+
+    expect(DateTime(1593, 7, 8).isAtSameMonthAs(null), false);
+    expect(DateTime(1903, 9, 25).isAtSameMonthAs(DateTime(1970, 2, 25)), false);
+    expect(DateTime(1929, 3, 22).isAtSameMonthAs(DateTime(1929, 3, 22)), true);
+
+    expect(DateTime(1593, 7, 8).isAtSameDayAs(null), false);
+    expect(DateTime(1903, 9, 25).isAtSameDayAs(DateTime(1970, 2, 25)), false);
+    expect(DateTime(1929, 3, 22).isAtSameDayAs(DateTime(1929, 3, 22)), true);
+  });
+}

whatsnew/whatsnew-en-US

@@ -1 +1,6 @@
 Thanks for using Aves!
+v1.2.6:
+- subsampling and tiling of large images
+- support for TIFF images (single page only)
+- optional minimap in viewer overlay
+Full changelog available on Github