Update thumbnail generation mechanism

lib/db/db_helper.dart

@@ -11,6 +11,7 @@ class DatabaseHelper {
 
   static final table = 'photos';
 
+  static final columnLocalId = 'local_id';
   static final columnLocalPath = 'local_path';
   static final columnThumbnailPath = 'thumbnail_path';
   static final columnPath = 'path';
@@ -42,6 +43,7 @@ class DatabaseHelper {
   Future _onCreate(Database db, int version) async {
     await db.execute('''
           CREATE TABLE $table (
+            $columnLocalId TEXT,
             $columnLocalPath TEXT NOT NULL,
             $columnThumbnailPath TEXT NOT NULL,
             $columnPath TEXT,
@@ -123,6 +125,7 @@ class DatabaseHelper {
 
   Map<String, dynamic> _getRowForPhoto(Photo photo) {
     var row = new Map<String, dynamic>();
+    row[columnLocalId] = photo.localId;
     row[columnLocalPath] = photo.localPath;
     row[columnThumbnailPath] = photo.thumbnailPath;
     row[columnPath] = photo.path;

lib/models/photo.dart

@@ -1,12 +1,10 @@
 import 'dart:io';
 
 import 'package:crypto/crypto.dart';
-import 'package:flutter/foundation.dart';
-import 'package:image/image.dart';
-import 'package:path_provider/path_provider.dart';
 import 'package:photo_manager/photo_manager.dart';
 
 class Photo {
+  String localId;
   String path;
   String localPath;
   String thumbnailPath;
@@ -22,7 +20,8 @@ class Photo {
         syncTimestamp = json["syncTimestamp"];
 
   Photo.fromRow(Map<String, dynamic> row)
-      : localPath = row["local_path"],
+      : localId = row["local_id"],
+        localPath = row["local_path"],
         thumbnailPath = row["thumbnail_path"],
         path = row["path"],
         hash = row["hash"],
@@ -33,34 +32,14 @@ class Photo {
   static Future<Photo> fromAsset(AssetEntity asset) async {
     Photo photo = Photo();
     var file = (await asset.originFile);
+    photo.localId = asset.id;
     photo.localPath = file.path;
     photo.hash = getHash(file);
     photo.thumbnailPath = file.path;
     return photo;
   }
 
-  static Future<Photo> setThumbnail(Photo photo) async {
-    var externalPath = (await getApplicationDocumentsDirectory()).path;
-    var thumbnailPath =
-        externalPath + "/photos/thumbnails/" + photo.hash + ".thumbnail";
-    var args = Map<String, String>();
-    args["assetPath"] = photo.localPath;
-    args["thumbnailPath"] = thumbnailPath;
-    photo.thumbnailPath = thumbnailPath;
-    return compute(getThumbnailPath, args).then((value) => photo);
-  }
-
   static String getHash(File file) {
     return sha256.convert(file.readAsBytesSync()).toString();
   }
 }
-
-Future<void> getThumbnailPath(Map<String, String> args) async {
-  return File(args["thumbnailPath"])
-    ..writeAsBytes(_getThumbnail(args["assetPath"]));
-}
-
-List<int> _getThumbnail(String path) {
-  Image image = decodeImage(File(path).readAsBytesSync());
-  return encodePng(copyResize(image, width: 250));
-}

lib/ui/face_search_results_page.dart

@@ -71,7 +71,7 @@ class FaceSearchResultsPage extends StatelessWidget {
       future: DatabaseHelper.instance.getPhotoByPath(path),
       builder: (_, snapshot) {
         if (snapshot.hasData) {
-          return ImageWidget(path: snapshot.data.thumbnailPath);
+          return ImageWidget(snapshot.data);
         } else if (snapshot.hasError) {
           return Container(
             margin: EdgeInsets.all(2),

lib/ui/gallery.dart

@@ -68,7 +68,7 @@ class _GalleryState extends State<Gallery> {
       },
       child: Padding(
         padding: const EdgeInsets.all(1.0),
-        child: ImageWidget(path: photo.thumbnailPath),
+        child: ImageWidget(photo),
       ),
     );
   }

lib/ui/image_widget.dart

@@ -1,17 +1,19 @@
-import 'dart:io';
+import 'dart:typed_data';
 
 import 'package:flutter/material.dart';
 import 'package:myapp/core/lru_map.dart';
+import 'package:myapp/models/photo.dart';
 import 'package:myapp/photo_loader.dart';
 import 'package:myapp/ui/loading_widget.dart';
+import 'package:photo_manager/photo_manager.dart';
 import 'package:provider/provider.dart';
 
 class ImageWidget extends StatefulWidget {
-  final String path;
+  final Photo photo;
 
-  const ImageWidget({
+  const ImageWidget(
+    this.photo, {
     Key key,
-    this.path,
   }) : super(key: key);
   @override
   _ImageWidgetState createState() => _ImageWidgetState();
@@ -22,7 +24,7 @@ class _ImageWidgetState extends State<ImageWidget> {
 
   @override
   Widget build(BuildContext context) {
-    final path = widget.path;
+    final path = widget.photo.localPath;
     final size = 124;
     final cachedImage = ImageLruCache.getData(path, size);
 
@@ -31,12 +33,15 @@ class _ImageWidgetState extends State<ImageWidget> {
     if (cachedImage != null) {
       image = cachedImage;
     } else {
-      image = FutureBuilder<Image>(
-        future: _buildImageWidget(path, size),
+      image = FutureBuilder<Uint8List>(
+        future:
+            AssetEntity(id: widget.photo.localId).thumbDataWithSize(size, size),
         builder: (context, snapshot) {
           if (snapshot.hasData) {
-            ImageLruCache.setData(path, size, snapshot.data);
-            return snapshot.data;
+            Image image = Image.memory(snapshot.data,
+                width: 124, height: 124, fit: BoxFit.cover);
+            ImageLruCache.setData(path, size, image);
+            return image;
           } else {
             return loadWidget;
           }
@@ -47,15 +52,10 @@ class _ImageWidgetState extends State<ImageWidget> {
     return image;
   }
 
-  Future<Image> _buildImageWidget(String path, num size) async {
-    return Image.file(File(path),
-        width: size.toDouble(), height: size.toDouble(), fit: BoxFit.cover);
-  }
-
   @override
   void didUpdateWidget(ImageWidget oldWidget) {
     super.didUpdateWidget(oldWidget);
-    if (widget.path != oldWidget.path) {
+    if (widget.photo.localPath != oldWidget.photo.localPath) {
       setState(() {});
     }
   }