fullscreen: decode image from URI instead of path

android/app/src/main/java/deckers/thibault/aves/channelhandlers/ImageFileHandler.java

@@ -7,6 +7,9 @@ import android.os.Looper;
 
 import androidx.annotation.NonNull;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
 import java.util.Map;
 
 import deckers.thibault.aves.model.ImageEntry;
@@ -38,6 +41,9 @@ public class ImageFileHandler implements MethodChannel.MethodCallHandler {
             case "getImageEntry":
                 getImageEntry(call, result);
                 break;
+            case "readAsBytes":
+                readAsBytes(call, result);
+                break;
             case "getImageBytes":
                 getImageBytes(call, result);
                 break;
@@ -59,6 +65,25 @@ public class ImageFileHandler implements MethodChannel.MethodCallHandler {
         }
     }
 
+    private void readAsBytes(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {
+        String uri = call.argument("uri");
+
+        byte[] data = null;
+        try (InputStream is = activity.getContentResolver().openInputStream(Uri.parse(uri))) {
+            if (is != null) {
+                data = getBytes(is);
+            }
+        } catch (IOException ex) {
+            // ignore
+        }
+
+        if (data != null) {
+            result.success(data);
+        } else {
+            result.error("readAsBytes-null", "failed to read bytes from uri=" + uri, null);
+        }
+    }
+
     private void getImageBytes(@NonNull MethodCall call, @NonNull MethodChannel.Result result) {
         Map entryMap = call.argument("entry");
         Integer width = call.argument("width");
@@ -189,4 +214,18 @@ public class ImageFileHandler implements MethodChannel.MethodCallHandler {
             }
         });
     }
+
+    // convenience methods
+
+    private byte[] getBytes(InputStream inputStream) throws IOException {
+        ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
+        int bufferSize = 1024;
+        byte[] buffer = new byte[bufferSize];
+
+        int len = 0;
+        while ((len = inputStream.read(buffer)) != -1) {
+            byteBuffer.write(buffer, 0, len);
+        }
+        return byteBuffer.toByteArray();
+    }
 }

lib/model/image_file_service.dart

@@ -29,6 +29,18 @@ class ImageFileService {
     return null;
   }
 
+  static Future<Uint8List> readAsBytes(String uri) async {
+    try {
+      final result = await platform.invokeMethod('readAsBytes', <String, dynamic>{
+        'uri': uri,
+      });
+      return result as Uint8List;
+    } on PlatformException catch (e) {
+      debugPrint('readAsBytes failed with exception=${e.message}');
+    }
+    return Uint8List(0);
+  }
+
   static Future<Uint8List> getImageBytes(ImageEntry entry, int width, int height) async {
     if (width > 0 && height > 0) {
 //      debugPrint('getImageBytes width=$width path=${entry.path}');

lib/widgets/fullscreen/image_uri.dart

@@ -0,0 +1,55 @@
+import 'dart:typed_data';
+import 'dart:ui' as ui show Codec;
+
+import 'package:aves/model/image_file_service.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+
+class UriImage extends ImageProvider<UriImage> {
+  const UriImage(this.uri, {this.scale = 1.0})
+      : assert(uri != null),
+        assert(scale != null);
+
+  final String uri;
+
+  final double scale;
+
+  @override
+  Future<UriImage> obtainKey(ImageConfiguration configuration) {
+    return SynchronousFuture<UriImage>(this);
+  }
+
+  @override
+  ImageStreamCompleter load(UriImage key, DecoderCallback decode) {
+    return MultiFrameImageStreamCompleter(
+      codec: _loadAsync(key, decode),
+      scale: key.scale,
+      informationCollector: () sync* {
+        yield ErrorDescription('Uri: $uri');
+      },
+    );
+  }
+
+  Future<ui.Codec> _loadAsync(UriImage key, DecoderCallback decode) async {
+    assert(key == this);
+
+    final Uint8List bytes = await ImageFileService.readAsBytes(uri);
+    if (bytes.lengthInBytes == 0) {
+      return null;
+    }
+
+    return await decode(bytes);
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (other.runtimeType != runtimeType) return false;
+    return other is UriImage && other.uri == uri && other.scale == scale;
+  }
+
+  @override
+  int get hashCode => hashValues(uri, scale);
+
+  @override
+  String toString() => '${objectRuntimeType(this, 'UriImage')}("$uri", scale: $scale)';
+}

lib/widgets/fullscreen/image_view.dart

@@ -1,10 +1,8 @@
-import 'dart:io';
-
 import 'package:aves/model/image_entry.dart';
+import 'package:aves/widgets/fullscreen/image_uri.dart';
 import 'package:aves/widgets/fullscreen/video.dart';
 import 'package:flutter/material.dart';
 import 'package:photo_view/photo_view.dart';
-import 'package:transparent_image/transparent_image.dart';
 import 'package:tuple/tuple.dart';
 import 'package:video_player/video_player.dart';
 
@@ -48,7 +46,7 @@ class ImageView extends StatelessWidget {
     return PhotoView(
       // key includes size and orientation to refresh when the image is rotated
       key: ValueKey('${entry.orientationDegrees}_${entry.width}_${entry.height}_${entry.path}'),
-      imageProvider: entry.path != null ? FileImage(File(entry.path)) : MemoryImage(kTransparentImage),
+      imageProvider: UriImage(entry.uri),
       loadingBuilder: (context, event) => const Center(
         child: SizedBox(
           width: 64,