🚀 Abstract viewAsset in AssetPickerBuilderDelegate (#391)

* 🚀 Abstract `viewAsset` in `AssetPickerBuilderDelegate`

* 🚀 Adopt in the example

* 🔖 8.2.0

Author: AlexV525

CHANGELOG.md

@@ -4,6 +4,12 @@ that can be found in the LICENSE file. -->
 
 # Changelog
 
+## 8.2.0
+
+### New features
+
+- Allow overrides `viewAsset` in the `AssetPickerBuilderDelegate`. (#391)
+
 ## 8.1.4
 
 ### Fixes

example/lib/customs/pickers/directory_file_asset_picker.dart

@@ -388,6 +388,37 @@ class FileAssetPickerBuilder
   @override
   bool get isSingleAssetMode => provider.maxAssets == 1;
 
+  @override
+  Future<void> viewAsset(
+    BuildContext context,
+    int index,
+    AssetEntity currentAsset,
+  ) async {
+    final List<File>? result = await Navigator.of(context).push<List<File>?>(
+      PageRouteBuilder<List<File>>(
+        pageBuilder: (
+          BuildContext context,
+          Animation<double> animation,
+          Animation<double> secondaryAnimation,
+        ) {
+          return AssetPickerViewer<File, Directory>(
+            builder: FileAssetPickerViewerBuilderDelegate(
+              currentIndex: index,
+              previewAssets: provider.selectedAssets,
+              provider: FileAssetPickerViewerProvider(provider.selectedAssets),
+              themeData: AssetPicker.themeData(themeColor),
+              selectedAssets: provider.selectedAssets,
+              selectorProvider: provider,
+            ),
+          );
+        },
+      ),
+    );
+    if (result != null) {
+      Navigator.of(context).maybePop(result);
+    }
+  }
+
   Future<List<File>?> pushToPicker(
     BuildContext context, {
     required int index,

example/pubspec.yaml

@@ -1,6 +1,6 @@
 name: wechat_assets_picker_demo
 description: The demo project for the wechat_assets_picker package.
-version: 8.1.4+29
+version: 8.2.0+30
 publish_to: none
 
 environment:

guides/migration_guide.md

@@ -8,11 +8,34 @@ This document gathered all breaking changes and migrations requirement between m
 
 ## Major versions
 
+- [8.2.0](#820)
 - [8.0.0](#800)
 - [7.0.0](#700)
 - [6.0.0](#600)
 - [5.0.0](#500)
 
+## 8.2.0
+
+### Summary
+
+Delegates that extend `AssetPickerBuilderDelegate` should now implement `viewAsset`.
+Delegates that extend `DefaultAssetPickerBuilderDelegate` are not required to do so.
+
+### Details
+
+`viewAsset` is abstracted in the `AssetPickerBuilderDelegate`:
+
+```dart
+Future<void> viewAsset(
+  BuildContext context,
+  int index,
+  AssetEntity currentAsset,
+);
+```
+
+The new method is implemented in the `DefaultAssetPickerBuilderDelegate`.
+It's a private method previously which not allow to modify.
+
 ## 8.0.0
 
 ### Summary

lib/src/delegates/asset_picker_builder_delegate.dart

@@ -232,6 +232,14 @@ abstract class AssetPickerBuilderDelegate<Asset, Path> {
   /// 系统发出资源变更的通知时调用的方法
   Future<void> onAssetsChanged(MethodCall call, StateSetter setState) async {}
 
+  /// Determine how to browse assets in the viewer.
+  /// 定义如何在查看器中浏览资源
+  Future<void> viewAsset(
+    BuildContext context,
+    int index,
+    AssetEntity currentAsset,
+  );
+
   /// Yes, the build method.
   /// 没错，是它是它就是它，我们亲爱的 build 方法~
   Widget build(BuildContext context);
@@ -824,19 +832,20 @@ class DefaultAssetPickerBuilderDelegate
     }
   }
 
-  Future<void> _pushAssetToViewer(
+  @override
+  Future<void> viewAsset(
     BuildContext context,
     int index,
-    AssetEntity asset,
+    AssetEntity currentAsset,
   ) async {
     final DefaultAssetPickerProvider provider =
         context.read<DefaultAssetPickerProvider>();
     bool selectedAllAndNotSelected() =>
-        !provider.selectedAssets.contains(asset) &&
+        !provider.selectedAssets.contains(currentAsset) &&
         provider.selectedMaximumAssets;
     bool selectedPhotosAndIsVideo() =>
         isWeChatMoment &&
-        asset.type == AssetType.video &&
+        currentAsset.type == AssetType.video &&
         provider.selectedAssets.isNotEmpty;
     // When we reached the maximum select count and the asset
     // is not selected, do nothing.
@@ -850,16 +859,16 @@ class DefaultAssetPickerBuilderDelegate
     final List<AssetEntity>? selected;
     final int effectiveIndex;
     if (isWeChatMoment) {
-      if (asset.type == AssetType.video) {
-        current = <AssetEntity>[asset];
+      if (currentAsset.type == AssetType.video) {
+        current = <AssetEntity>[currentAsset];
         selected = null;
         effectiveIndex = 0;
       } else {
         current = provider.currentAssets
             .where((AssetEntity e) => e.type == AssetType.image)
             .toList();
         selected = provider.selectedAssets;
-        effectiveIndex = current.indexOf(asset);
+        effectiveIndex = current.indexOf(currentAsset);
       }
     } else {
       current = provider.currentAssets;
@@ -1323,7 +1332,7 @@ class DefaultAssetPickerBuilderDelegate
               onTap: () => selectAsset(context, asset, isSelected),
               onTapHint: semanticsTextDelegate.sActionSelectHint,
               onLongPress: isPreviewEnabled
-                  ? () => _pushAssetToViewer(context, index, asset)
+                  ? () => viewAsset(context, index, asset)
                   : null,
               onLongPressHint: semanticsTextDelegate.sActionPreviewHint,
               selected: isSelected,
@@ -1336,7 +1345,7 @@ class DefaultAssetPickerBuilderDelegate
                 // Regression https://github.com/flutter/flutter/issues/35112.
                 onLongPress:
                     isPreviewEnabled && context.mediaQuery.accessibleNavigation
-                        ? () => _pushAssetToViewer(context, index, asset)
+                        ? () => viewAsset(context, index, asset)
                         : null,
                 child: IndexedSemantics(
                   index: semanticIndex(index),
@@ -2041,9 +2050,7 @@ class DefaultAssetPickerBuilderDelegate
     final double indicatorSize = context.mediaQuery.size.width / gridCount / 3;
     return Positioned.fill(
       child: GestureDetector(
-        onTap: isPreviewEnabled
-            ? () => _pushAssetToViewer(context, index, asset)
-            : null,
+        onTap: isPreviewEnabled ? () => viewAsset(context, index, asset) : null,
         child: Consumer<DefaultAssetPickerProvider>(
           builder: (_, DefaultAssetPickerProvider p, __) {
             final int index = p.selectedAssets.indexOf(asset);

pubspec.yaml

@@ -3,7 +3,7 @@ description: |
   An audio/video/image picker in pure Dart which is the same with WeChat,
   support multi picking, custom item and delegates override.
 repository: https://github.com/fluttercandies/flutter_wechat_assets_picker
-version: 8.1.4
+version: 8.2.0
 
 environment:
   sdk: '>=2.17.0 <3.0.0'