From 1d6103c0c01dc4abb9f9a4473d5661d0640346bf Mon Sep 17 00:00:00 2001
From: Thibault Deckers <thibault.deckers@gmail.com>
Date: Tue, 28 Apr 2020 11:18:18 +0900
Subject: [PATCH] scoped storage: fixed opening files and reading metadata

---
 android/app/src/main/AndroidManifest.xml      |  3 ++
 .../aves/channelhandlers/MetadataHandler.java | 33 +++----------
 .../aves/decoder/VideoThumbnailFetcher.java   |  8 ++--
 .../thibault/aves/model/ImageEntry.java       | 38 +++++++--------
 .../thibault/aves/utils/FileUtils.java        |  4 +-
 .../thibault/aves/utils/StorageUtils.java     | 47 +++++++++++++++++++
 lib/main.dart                                 |  2 +-
 7 files changed, 79 insertions(+), 56 deletions(-)

diff --git a/android/app/src/main/AndroidManifest.xml b/android/app/src/main/AndroidManifest.xml
index 90f88c34a..799408295 100644
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -7,6 +7,9 @@
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <uses-permission android:name="android.permission.INTERNET" />
 
+    <!-- to access media with unredacted metadata with scoped storage (Android 10+) -->
+    <uses-permission android:name="android.permission.ACCESS_MEDIA_LOCATION" />
+
     <!-- TODO remove this permission once this issue is fixed:
     https://github.com/flutter/flutter/issues/42349
     https://github.com/flutter/flutter/issues/42451
diff --git a/android/app/src/main/java/deckers/thibault/aves/channelhandlers/MetadataHandler.java b/android/app/src/main/java/deckers/thibault/aves/channelhandlers/MetadataHandler.java
index 0b338f642..34322e595 100644
--- a/android/app/src/main/java/deckers/thibault/aves/channelhandlers/MetadataHandler.java
+++ b/android/app/src/main/java/deckers/thibault/aves/channelhandlers/MetadataHandler.java
@@ -26,7 +26,6 @@ import com.drew.metadata.gif.GifAnimationDirectory;
 import com.drew.metadata.webp.WebpDirectory;
 import com.drew.metadata.xmp.XmpDirectory;
 
-import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.InputStream;
 import java.util.HashMap;
@@ -38,6 +37,7 @@ import java.util.regex.Pattern;
 import deckers.thibault.aves.utils.Constants;
 import deckers.thibault.aves.utils.MetadataHelper;
 import deckers.thibault.aves.utils.MimeTypes;
+import deckers.thibault.aves.utils.StorageUtils;
 import io.flutter.plugin.common.MethodCall;
 import io.flutter.plugin.common.MethodChannel;
 
@@ -97,18 +97,13 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
         return mimeType != null && mimeType.startsWith(MimeTypes.VIDEO);
     }
 
-    private InputStream getInputStream(String path, String uri) throws FileNotFoundException {
-        // FileInputStream is faster than input stream from ContentResolver
-        return path != null ? new FileInputStream(path) : context.getContentResolver().openInputStream(Uri.parse(uri));
-    }
-
     private void getAllMetadata(MethodCall call, MethodChannel.Result result) {
         String path = call.argument("path");
         String uri = call.argument("uri");
 
         Map<String, Map<String, String>> metadataMap = new HashMap<>();
 
-        try (InputStream is = getInputStream(path, uri)) {
+        try (InputStream is = StorageUtils.openInputStream(context, Uri.parse(uri), path)) {
             Metadata metadata = ImageMetadataReader.readMetadata(is);
             for (Directory dir : metadata.getDirectories()) {
                 if (dir.getTagCount() > 0) {
@@ -158,13 +153,7 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
         // unnamed fallback directory
         metadataMap.put("", dirMap);
 
-        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
-        try {
-            if (path != null) {
-                retriever.setDataSource(path);
-            } else {
-                retriever.setDataSource(context, Uri.parse(uri));
-            }
+        try (MediaMetadataRetriever retriever = StorageUtils.openMetadataRetriever(context, Uri.parse(uri), path)) {
             for (Map.Entry<Integer, String> kv : Constants.MEDIA_METADATA_KEYS.entrySet()) {
                 Integer key = kv.getKey();
                 String value = retriever.extractMetadata(key);
@@ -183,8 +172,6 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
             result.success(metadataMap);
         } catch (Exception e) {
             result.error("getAllVideoMetadataFallback-exception", "failed to get metadata for uri=" + uri + ", path=" + path, e.getMessage());
-        } finally {
-            retriever.release();
         }
     }
 
@@ -195,7 +182,7 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
 
         Map<String, Object> metadataMap = new HashMap<>();
 
-        try (InputStream is = getInputStream(path, uri)) {
+        try (InputStream is = StorageUtils.openInputStream(context, Uri.parse(uri), path)) {
             if (!MimeTypes.MP2T.equals(mimeType)) {
                 Metadata metadata = ImageMetadataReader.readMetadata(is);
 
@@ -253,13 +240,7 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
             }
 
             if (isVideo(mimeType)) {
-                MediaMetadataRetriever retriever = new MediaMetadataRetriever();
-                try {
-                    if (path != null) {
-                        retriever.setDataSource(path);
-                    } else {
-                        retriever.setDataSource(context, Uri.parse(uri));
-                    }
+                try (MediaMetadataRetriever retriever = StorageUtils.openMetadataRetriever(context, Uri.parse(uri), path)) {
                     String dateString = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DATE);
                     String rotationString = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION);
                     String locationString = retriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_LOCATION);
@@ -295,8 +276,6 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
                     }
                 } catch (Exception e) {
                     result.error("getCatalogMetadata-exception", "failed to get video metadata for uri=" + uri + ", path=" + path, e.getMessage());
-                } finally {
-                    retriever.release();
                 }
             }
             result.success(metadataMap);
@@ -321,7 +300,7 @@ public class MetadataHandler implements MethodChannel.MethodCallHandler {
             return;
         }
 
-        try (InputStream is = getInputStream(path, uri)) {
+        try (InputStream is = StorageUtils.openInputStream(context, Uri.parse(uri), path)) {
             Metadata metadata = ImageMetadataReader.readMetadata(is);
             ExifSubIFDDirectory directory = metadata.getFirstDirectoryOfType(ExifSubIFDDirectory.class);
             if (directory != null) {
diff --git a/android/app/src/main/java/deckers/thibault/aves/decoder/VideoThumbnailFetcher.java b/android/app/src/main/java/deckers/thibault/aves/decoder/VideoThumbnailFetcher.java
index ff39a1bf0..9cea8aea2 100644
--- a/android/app/src/main/java/deckers/thibault/aves/decoder/VideoThumbnailFetcher.java
+++ b/android/app/src/main/java/deckers/thibault/aves/decoder/VideoThumbnailFetcher.java
@@ -13,6 +13,8 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 
+import deckers.thibault.aves.utils.StorageUtils;
+
 class VideoThumbnailFetcher implements DataFetcher<InputStream> {
     private final VideoThumbnail model;
 
@@ -22,9 +24,7 @@ class VideoThumbnailFetcher implements DataFetcher<InputStream> {
 
     @Override
     public void loadData(@NonNull Priority priority, @NonNull DataCallback<? super InputStream> callback) {
-        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
-        try {
-            retriever.setDataSource(model.getContext(), model.getUri());
+        try (MediaMetadataRetriever retriever = StorageUtils.openMetadataRetriever(model.getContext(), model.getUri(), null)) {
             byte[] picture = retriever.getEmbeddedPicture();
             if (picture != null) {
                 callback.onDataReady(new ByteArrayInputStream(picture));
@@ -40,8 +40,6 @@ class VideoThumbnailFetcher implements DataFetcher<InputStream> {
             }
         } catch (Exception ex) {
             callback.onLoadFailed(ex);
-        } finally {
-            retriever.release();
         }
     }
 
diff --git a/android/app/src/main/java/deckers/thibault/aves/model/ImageEntry.java b/android/app/src/main/java/deckers/thibault/aves/model/ImageEntry.java
index 5b27b979d..4368bbdb1 100644
--- a/android/app/src/main/java/deckers/thibault/aves/model/ImageEntry.java
+++ b/android/app/src/main/java/deckers/thibault/aves/model/ImageEntry.java
@@ -20,9 +20,6 @@ import com.drew.metadata.jpeg.JpegDirectory;
 import com.drew.metadata.mp4.Mp4Directory;
 import com.drew.metadata.mp4.media.Mp4VideoDirectory;
 
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.HashMap;
@@ -31,6 +28,7 @@ import java.util.TimeZone;
 
 import deckers.thibault.aves.utils.MetadataHelper;
 import deckers.thibault.aves.utils.MimeTypes;
+import deckers.thibault.aves.utils.StorageUtils;
 
 import static deckers.thibault.aves.utils.MetadataHelper.getOrientationDegreesForExifCode;
 
@@ -38,11 +36,21 @@ public class ImageEntry {
     public Uri uri; // content or file URI
     public String path; // best effort to get local path
 
-    public String mimeType, title, bucketDisplayName;
+    public String mimeType;
+    @Nullable
+    public String title;
+    @Nullable
+    private String bucketDisplayName;
     @Nullable
     public Integer width, height, orientationDegrees;
     @Nullable
-    public Long sizeBytes, dateModifiedSecs, sourceDateTakenMillis, durationMillis;
+    public Long sizeBytes;
+    @Nullable
+    public Long dateModifiedSecs;
+    @Nullable
+    private Long sourceDateTakenMillis;
+    @Nullable
+    private Long durationMillis;
 
     public ImageEntry() {
     }
@@ -101,10 +109,6 @@ public class ImageEntry {
         return durationMillis != null && durationMillis > 0;
     }
 
-    public String getFilename() {
-        return path == null ? null : new File(path).getName();
-    }
-
     private boolean isImage() {
         return mimeType.startsWith(MimeTypes.IMAGE);
     }
@@ -119,11 +123,6 @@ public class ImageEntry {
 
     // metadata retrieval
 
-    private InputStream getInputStream(Context context) throws FileNotFoundException {
-        // FileInputStream is faster than input stream from ContentResolver
-        return path != null ? new FileInputStream(path) : context.getContentResolver().openInputStream(uri);
-    }
-
     // expects entry with: uri/path, mimeType
     // finds: width, height, orientation/rotation, date, title, duration
     public ImageEntry fillPreCatalogMetadata(Context context) {
@@ -138,10 +137,7 @@ public class ImageEntry {
     // expects entry with: uri/path, mimeType
     // finds: width, height, orientation/rotation, date, title, duration
     private void fillByMediaMetadataRetriever(Context context) {
-        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
-        try {
-            retriever.setDataSource(context, uri);
-
+        try (MediaMetadataRetriever retriever = StorageUtils.openMetadataRetriever(context, uri, path)) {
             String width = null, height = null, rotation = null, durationMillis = null;
             if (isImage()) {
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
@@ -181,8 +177,6 @@ public class ImageEntry {
             }
         } catch (Exception e) {
             // ignore
-        } finally {
-            retriever.release();
         }
     }
 
@@ -191,7 +185,7 @@ public class ImageEntry {
     private void fillByMetadataExtractor(Context context) {
         if (MimeTypes.SVG.equals(mimeType)) return;
 
-        try (InputStream is = getInputStream(context)) {
+        try (InputStream is = StorageUtils.openInputStream(context, uri, path)) {
             Metadata metadata = ImageMetadataReader.readMetadata(is);
 
             if (MimeTypes.JPEG.equals(mimeType)) {
@@ -253,7 +247,7 @@ public class ImageEntry {
     private void fillByBitmapDecode(Context context) {
         if (MimeTypes.SVG.equals(mimeType)) return;
 
-        try (InputStream is = getInputStream(context)) {
+        try (InputStream is = StorageUtils.openInputStream(context, uri, path)) {
             BitmapFactory.Options options = new BitmapFactory.Options();
             options.inJustDecodeBounds = true;
             BitmapFactory.decodeStream(is, null, options);
diff --git a/android/app/src/main/java/deckers/thibault/aves/utils/FileUtils.java b/android/app/src/main/java/deckers/thibault/aves/utils/FileUtils.java
index a1a1ab178..174f88624 100644
--- a/android/app/src/main/java/deckers/thibault/aves/utils/FileUtils.java
+++ b/android/app/src/main/java/deckers/thibault/aves/utils/FileUtils.java
@@ -17,7 +17,9 @@
  * https://raw.githubusercontent.com/iPaulPro/aFileChooser/master/aFileChooser/src/com/ipaulpro/afilechooser/utils/FileUtils.java
  */
 
-// TLAD: copied from https://raw.githubusercontent.com/flutter/plugins/master/packages/image_picker/android/src/main/java/io/flutter/plugins/imagepicker/FileUtils.java
+// TLAD: formatted code copied from:
+// https://raw.githubusercontent.com/flutter/plugins/master/packages/image_picker/android/src/main/java/io/flutter/plugins/imagepicker/FileUtils.java
+// do not add code to this file!
 
 package deckers.thibault.aves.utils;
 
diff --git a/android/app/src/main/java/deckers/thibault/aves/utils/StorageUtils.java b/android/app/src/main/java/deckers/thibault/aves/utils/StorageUtils.java
index c650a194d..e795a1fb3 100644
--- a/android/app/src/main/java/deckers/thibault/aves/utils/StorageUtils.java
+++ b/android/app/src/main/java/deckers/thibault/aves/utils/StorageUtils.java
@@ -1,11 +1,14 @@
 package deckers.thibault.aves.utils;
 
 import android.annotation.SuppressLint;
+import android.content.ContentResolver;
 import android.content.Context;
+import android.media.MediaMetadataRetriever;
 import android.net.Uri;
 import android.os.Build;
 import android.os.Environment;
 import android.os.ParcelFileDescriptor;
+import android.provider.MediaStore;
 import android.text.TextUtils;
 import android.util.Log;
 import android.webkit.MimeTypeMap;
@@ -16,7 +19,10 @@ import com.google.common.base.Splitter;
 import com.google.common.collect.Lists;
 
 import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -28,6 +34,47 @@ import java.util.Set;
 public class StorageUtils {
     private static final String LOG_TAG = Utils.createLogTag(StorageUtils.class);
 
+    private static boolean isMediaStoreContentUri(Uri uri) {
+        // a URI's authority is [userinfo@]host[:port]
+        // but we only want the host when comparing to Media Store's "authority"
+        return uri != null && ContentResolver.SCHEME_CONTENT.equalsIgnoreCase(uri.getScheme()) && MediaStore.AUTHORITY.equalsIgnoreCase(uri.getHost());
+    }
+
+    public static InputStream openInputStream(Context context, Uri uri, String path) throws FileNotFoundException {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            // we get a permission denial if we require original from a provider other than the media store
+            if (isMediaStoreContentUri(uri)) {
+                uri = MediaStore.setRequireOriginal(uri);
+            }
+            return context.getContentResolver().openInputStream(uri);
+        }
+
+        // on Android <Q, we directly work with file paths if possible,
+        // as `FileInputStream` is faster than input stream from `ContentResolver`
+        return path != null ? new FileInputStream(path) : context.getContentResolver().openInputStream(uri);
+    }
+
+    public static MediaMetadataRetriever openMetadataRetriever(Context context, Uri uri, String path) {
+        MediaMetadataRetriever retriever = new MediaMetadataRetriever();
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            // we get a permission denial if we require original from a provider other than the media store
+            if (isMediaStoreContentUri(uri)) {
+                uri = MediaStore.setRequireOriginal(uri);
+            }
+            retriever.setDataSource(context, uri);
+            return retriever;
+        }
+
+        // on Android <Q, we directly work with file paths if possible
+        if (path != null) {
+            retriever.setDataSource(path);
+        } else {
+            retriever.setDataSource(context, uri);
+        }
+        return retriever;
+    }
+
     /**
      * Returns all available SD-Cards in the system (include emulated)
      * <p/>
diff --git a/lib/main.dart b/lib/main.dart
index dd5148689..0b473fc78 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -68,7 +68,7 @@ class _HomePageState extends State<HomePage> {
     // TODO reduce permission check time
     final permissions = await [
       Permission.storage,
-      // unredacted EXIF with scoped storage (Android 10+)
+      // to access media with unredacted metadata with scoped storage (Android 10+)
       Permission.accessMediaLocation,
     ].request(); // 350ms
     if (permissions[Permission.storage] != PermissionStatus.granted) {