support Android KitKat API 19-20

CHANGELOG.md

@@ -3,7 +3,7 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 ### Added
-- support Android Lollipop & Marshmallow (API 21 ~ 23)
+- support Android KitKat, Lollipop & Marshmallow (API 19 ~ 23)
 
 ## [v1.3.4] - 2021-02-10
 ### Added

README.md

@@ -21,7 +21,7 @@ Aves is a gallery and metadata explorer app. It is built for Android, with Flutt
 - search and filter by country, place, XMP tag, type (animated, raster, vector…)
 - favorites
 - statistics
-- support Android API 21 ~ 30 (Lollipop ~ R)
+- support Android API 19 ~ 30 (KitKat ~ R)
 - Android integration (app shortcuts, handle view/pick intents)
 
 ## Known Issues

android/app/build.gradle

@@ -53,7 +53,7 @@ android {
 
     defaultConfig {
         applicationId "deckers.thibault.aves"
-        minSdkVersion 21
+        minSdkVersion 19
         targetSdkVersion 30 // same as compileSdkVersion
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName

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

@@ -51,13 +51,21 @@ class DebugHandler(private val context: Context) : MethodCallHandler {
 
     private fun getContextDirs() = hashMapOf(
         "cacheDir" to context.cacheDir,
-        "codeCacheDir" to context.codeCacheDir,
         "filesDir" to context.filesDir,
-        "noBackupFilesDir" to context.noBackupFilesDir,
         "obbDir" to context.obbDir,
         "externalCacheDir" to context.externalCacheDir,
     ).apply {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) put("dataDir", context.dataDir)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            putAll(
+                hashMapOf(
+                    "codeCacheDir" to context.codeCacheDir,
+                    "noBackupFilesDir" to context.noBackupFilesDir,
+                )
+            )
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            put("dataDir", context.dataDir)
+        }
     }.mapValues { it.value?.path }
 
     private fun getBitmapFactoryInfo(call: MethodCall, result: MethodChannel.Result) {

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

@@ -125,7 +125,8 @@ class ImageFileHandler(private val activity: Activity) : MethodCallHandler {
                 pageId = pageId,
                 sampleSize = sampleSize,
                 regionRect = regionRect,
-                imageSize = Size(imageWidth, imageHeight),
+                imageWidth = imageWidth,
+                imageHeight = imageHeight,
                 result = result,
             )
         }

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

@@ -6,6 +6,7 @@ import android.net.Uri
 import android.os.Build
 import android.os.Environment
 import android.os.storage.StorageManager
+import androidx.core.os.EnvironmentCompat
 import deckers.thibault.aves.channel.calls.Coresult.Companion.safe
 import deckers.thibault.aves.utils.PermissionManager
 import deckers.thibault.aves.utils.StorageUtils.getPrimaryVolumePath
@@ -61,12 +62,19 @@ class StorageHandler(private val context: Context) : MethodCallHandler {
             for (volumePath in getVolumePaths(context)) {
                 val volumeFile = File(volumePath)
                 try {
+                    val isPrimary = volumePath == primaryVolumePath
+                    val isRemovable = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                        Environment.isExternalStorageRemovable(volumeFile)
+                    } else {
+                        // random guess
+                        !isPrimary
+                    }
                     volumes.add(
                         hashMapOf(
                             "path" to volumePath,
-                            "isPrimary" to (volumePath == primaryVolumePath),
-                            "isRemovable" to Environment.isExternalStorageRemovable(volumeFile),
-                            "state" to Environment.getExternalStorageState(volumeFile)
+                            "isPrimary" to isPrimary,
+                            "isRemovable" to isRemovable,
+                            "state" to EnvironmentCompat.getStorageState(volumeFile)
                         )
                     )
                 } catch (e: IllegalArgumentException) {
@@ -119,6 +127,11 @@ class StorageHandler(private val context: Context) : MethodCallHandler {
             return
         }
 
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            result.error("revokeDirectoryAccess-unsupported", "volume access is not allowed before Android Lollipop", null)
+            return
+        }
+
         val success = PermissionManager.revokeDirectoryAccess(context, path)
         result.success(success)
     }

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

@@ -5,7 +5,7 @@ import io.flutter.plugin.common.MethodChannel
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler
 import java.util.*
 
-class TimeHandler() : MethodCallHandler {
+class TimeHandler : MethodCallHandler {
     override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
         when (call.method) {
             "getDefaultTimeZone" -> result.success(TimeZone.getDefault().id)

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

@@ -6,7 +6,6 @@ import android.graphics.BitmapFactory
 import android.graphics.BitmapRegionDecoder
 import android.graphics.Rect
 import android.net.Uri
-import android.util.Size
 import com.bumptech.glide.Glide
 import com.bumptech.glide.load.DecodeFormat
 import com.bumptech.glide.load.engine.DiskCacheStrategy
@@ -37,7 +36,8 @@ class RegionFetcher internal constructor(
         pageId: Int?,
         sampleSize: Int,
         regionRect: Rect,
-        imageSize: Size,
+        imageWidth: Int,
+        imageHeight: Int,
         result: MethodChannel.Result,
     ) {
         if (MimeTypes.isHeifLike(mimeType) && pageId != null) {
@@ -48,7 +48,8 @@ class RegionFetcher internal constructor(
                 pageId = null,
                 sampleSize = sampleSize,
                 regionRect = regionRect,
-                imageSize = imageSize,
+                imageWidth = imageWidth,
+                imageHeight = imageHeight,
                 result = result,
             )
             return
@@ -79,9 +80,9 @@ class RegionFetcher internal constructor(
 
             // 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
+            val effectiveRect = if (imageWidth != decoder.width || imageHeight != decoder.height) {
+                val xf = decoder.width.toDouble() / imageWidth
+                val yf = decoder.height.toDouble() / imageHeight
                 Rect(
                     (regionRect.left * xf).roundToInt(),
                     (regionRect.top * yf).roundToInt(),

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

@@ -1,6 +1,7 @@
 package deckers.thibault.aves.channel.streams
 
 import android.app.Activity
+import android.os.Build
 import android.os.Handler
 import android.os.Looper
 import android.util.Log
@@ -26,6 +27,16 @@ class StorageAccessStreamHandler(private val activity: Activity, arguments: Any?
         this.eventSink = eventSink
         handler = Handler(Looper.getMainLooper())
 
+        if (path == null) {
+            error("requestVolumeAccess-args", "failed because of missing arguments", null)
+            return
+        }
+
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            error("requestVolumeAccess-unsupported", "volume access is not allowed before Android Lollipop", null)
+            return
+        }
+
         requestVolumeAccess(activity, path!!, { success(true) }, { success(false) })
     }
 
@@ -42,6 +53,17 @@ class StorageAccessStreamHandler(private val activity: Activity, arguments: Any?
         endOfStream()
     }
 
+    @Suppress("SameParameterValue")
+    private fun error(errorCode: String, errorMessage: String, errorDetails: Any?) {
+        handler.post {
+            try {
+                eventSink.error(errorCode, errorMessage, errorDetails)
+            } catch (e: Exception) {
+                Log.w(LOG_TAG, "failed to use event sink", e)
+            }
+        }
+    }
+
     private fun endOfStream() {
         handler.post {
             try {

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

@@ -8,6 +8,7 @@ import android.os.Build
 import android.os.Environment
 import android.os.storage.StorageManager
 import android.util.Log
+import androidx.annotation.RequiresApi
 import deckers.thibault.aves.utils.StorageUtils.PathSegments
 import java.io.File
 import java.util.*
@@ -22,6 +23,7 @@ object PermissionManager {
     // permission request code to pending runnable
     private val pendingPermissionMap = ConcurrentHashMap<Int, PendingPermissionHandler>()
 
+    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
     fun requestVolumeAccess(activity: Activity, path: String, onGranted: () -> Unit, onDenied: () -> Unit) {
         Log.i(LOG_TAG, "request user to select and grant access permission to volume=$path")
 
@@ -106,29 +108,39 @@ object PermissionManager {
     }
 
     fun getRestrictedDirectories(context: Context): List<Map<String, String>> {
-        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+        val dirs = ArrayList<Map<String, String>>()
+        val sdkInt = Build.VERSION.SDK_INT
+
+        if (sdkInt >= Build.VERSION_CODES.R) {
             // cf https://developer.android.com/about/versions/11/privacy/storage#directory-access
             val volumePaths = StorageUtils.getVolumePaths(context)
-            ArrayList<Map<String, String>>().apply {
-                addAll(volumePaths.map {
-                    hashMapOf(
-                        "volumePath" to it,
-                        "relativeDir" to "",
-                    )
-                })
-                addAll(volumePaths.map {
-                    hashMapOf(
-                        "volumePath" to it,
-                        "relativeDir" to Environment.DIRECTORY_DOWNLOADS,
-                    )
-                })
-            }
-        } else {
-            // TODO TLAD add KitKat restriction (no SD card root access) if min version goes to API 19-20
-            ArrayList()
+            dirs.addAll(volumePaths.map {
+                hashMapOf(
+                    "volumePath" to it,
+                    "relativeDir" to "",
+                )
+            })
+            dirs.addAll(volumePaths.map {
+                hashMapOf(
+                    "volumePath" to it,
+                    "relativeDir" to Environment.DIRECTORY_DOWNLOADS,
+                )
+            })
+        } else if (sdkInt == Build.VERSION_CODES.KITKAT || sdkInt == Build.VERSION_CODES.KITKAT_WATCH) {
+            // no SD card volume access on KitKat
+            val primaryVolume = StorageUtils.getPrimaryVolumePath(context)
+            val nonPrimaryVolumes = StorageUtils.getVolumePaths(context).filter { it != primaryVolume }
+            dirs.addAll(nonPrimaryVolumes.map {
+                hashMapOf(
+                    "volumePath" to it,
+                    "relativeDir" to "",
+                )
+            })
         }
+        return dirs
     }
 
+    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
     fun revokeDirectoryAccess(context: Context, path: String): Boolean {
         return StorageUtils.convertDirPathToTreeUri(context, path)?.let {
             val flags = Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION

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

@@ -12,6 +12,7 @@ import android.provider.MediaStore
 import android.text.TextUtils
 import android.util.Log
 import android.webkit.MimeTypeMap
+import androidx.annotation.RequiresApi
 import com.commonsware.cwac.document.DocumentFileCompat
 import deckers.thibault.aves.utils.PermissionManager.getGrantedDirForPath
 import java.io.File
@@ -246,6 +247,7 @@ object StorageUtils {
     // e.g.
     // /storage/emulated/0/         -> content://com.android.externalstorage.documents/tree/primary%3A
     // /storage/10F9-3F13/Pictures/ -> content://com.android.externalstorage.documents/tree/10F9-3F13%3APictures
+    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
     fun convertDirPathToTreeUri(context: Context, dirPath: String): Uri? {
         val uuid = getVolumeUuidForTreeUri(context, dirPath)
         if (uuid != null) {
@@ -287,7 +289,7 @@ object StorageUtils {
 
     fun getDocumentFile(context: Context, anyPath: String, mediaUri: Uri): DocumentFileCompat? {
         try {
-            if (requireAccessPermission(context, anyPath)) {
+            if (requireAccessPermission(context, anyPath) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                 // need a document URI (not a media content URI) to open a `DocumentFile` output stream
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && isMediaStoreContentUri(mediaUri)) {
                     // cleanest API to get it
@@ -311,7 +313,7 @@ object StorageUtils {
     // returns null if directory does not exist and could not be created
     fun createDirectoryIfAbsent(context: Context, dirPath: String): DocumentFileCompat? {
         val cleanDirPath = ensureTrailingSeparator(dirPath)
-        return if (requireAccessPermission(context, cleanDirPath)) {
+        return if (requireAccessPermission(context, cleanDirPath) && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             val grantedDir = getGrantedDirForPath(context, cleanDirPath) ?: return null
             val rootTreeUri = convertDirPathToTreeUri(context, grantedDir) ?: return null
             var parentFile: DocumentFileCompat? = DocumentFileCompat.fromTreeUri(context, rootTreeUri) ?: return null