🐛 Fix selected assets not sync between thumbnail preview mode and grid view

Author: AlexV525

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 5.1.2
+
+- Fix selected assets unsynced between thumb preview mode and grid view.
+
 ## 5.1.1
 
 - Integrate `lastModified` to sort path entities by default.

lib/src/delegates/asset_picker_builder_delegate.dart

@@ -1139,9 +1139,13 @@ class DefaultAssetPickerBuilderDelegate
 
   @override
   Widget selectIndicator(BuildContext context, AssetEntity asset) {
-    return Selector<DefaultAssetPickerProvider, List<AssetEntity>>(
-      selector: (_, DefaultAssetPickerProvider p) => p.selectedAssets,
-      builder: (_, List<AssetEntity> selectedAssets, __) {
+    return Selector<DefaultAssetPickerProvider, int>(
+      selector: (_, DefaultAssetPickerProvider p) => p.selectedAssetsCount,
+      builder: (BuildContext context, int count, __) {
+        final List<AssetEntity> selectedAssets =
+            context.select<DefaultAssetPickerProvider, List<AssetEntity>>(
+          (DefaultAssetPickerProvider p) => p.selectedAssets,
+        );
         final bool selected = selectedAssets.contains(asset);
         final double indicatorSize = Screens.width / gridCount / 3;
         return Positioned(

lib/src/provider/asset_picker_provider.dart

@@ -178,6 +178,14 @@ abstract class AssetPickerProvider<A, P> extends ChangeNotifier {
     notifyListeners();
   }
 
+  /// How many assets have been selected.
+  /// 当前有资源已经被选择
+  ///
+  /// This getter provides a "Should Rebuild" condition judgement to [Selector]
+  /// with the preview widget's selective part.
+  /// 它为预览部件的选中部分的 [Selector] 提供了是否重建的条件。
+  int get selectedAssetsCount => _selectedAssets.length;
+
   /// 选中资源是否为空
   bool get isSelectedNotEmpty => selectedAssets.isNotEmpty;