🥅 Add exception handling

lib/src/constants/config.dart

@@ -13,6 +13,7 @@ import 'enums.dart';
 
 class AssetPickerConfig {
   const AssetPickerConfig({
+    this.internalExceptionHandler,
     this.selectedAssets,
     this.maxAssets = defaultMaxAssetsCount,
     this.pageSize = defaultAssetsPerPage,
@@ -61,6 +62,9 @@ class AssetPickerConfig {
           'Custom item did not set properly.',
         );
 
+  /// {@macro wechat_assets_picker.ExceptionHandler}
+  final ExceptionHandler? internalExceptionHandler;
+
   /// Selected assets.
   /// 已选中的资源
   final List<AssetEntity>? selectedAssets;

lib/src/constants/typedefs.dart

@@ -7,6 +7,12 @@ import 'dart:async';
 import 'package:flutter/widgets.dart';
 import 'package:photo_manager/photo_manager.dart' show PermissionState;
 
+/// {@template wechat_assets_picker.ExceptionHandler}
+/// Handles exceptions during internal calls.
+/// 处理内部方法调用时的异常。
+/// {@endtemplate}
+typedef ExceptionHandler = void Function(Object e, StackTrace s);
+
 /// {@template wechat_assets_picker.LoadingIndicatorBuilder}
 /// Build the loading indicator with the given [isAssetsEmpty].
 /// 根据给定的 [isAssetsEmpty] 构建加载指示器。

lib/src/delegates/asset_picker_builder_delegate.dart

@@ -19,6 +19,7 @@ import '../constants/enums.dart';
 import '../constants/extensions.dart';
 import '../constants/typedefs.dart';
 import '../delegates/asset_picker_text_delegate.dart';
+import '../internal/methods.dart';
 import '../internal/singleton.dart';
 import '../models/path_wrapper.dart';
 import '../provider/asset_picker_provider.dart';
@@ -1264,7 +1265,7 @@ class DefaultAssetPickerBuilderDelegate
     if (p.hasMoreToLoad) {
       if ((p.pageSize <= gridCount * 3 && index == length - 1) ||
           index == length - gridCount * 3) {
-        p.loadMoreAssets();
+        p.loadMoreAssets().catchError(handleException);
       }
     }
 

lib/src/delegates/asset_picker_delegate.dart

@@ -8,6 +8,7 @@ import 'package:photo_manager/photo_manager.dart';
 
 import '../constants/config.dart';
 import '../constants/constants.dart';
+import '../constants/typedefs.dart';
 import '../internal/methods.dart';
 import '../provider/asset_picker_provider.dart';
 import '../widget/asset_picker.dart';
@@ -104,13 +105,17 @@ class AssetPickerDelegate {
         locale: Localizations.maybeLocaleOf(context),
       ),
     );
+    AssetPicker.setInternalExceptionHandler(
+      pickerConfig.internalExceptionHandler,
+    );
     final List<AssetEntity>? result = await Navigator.of(
       context,
       rootNavigator: useRootNavigator,
     ).push<List<AssetEntity>>(
       pageRouteBuilder?.call(picker) ??
           AssetPickerPageRoute<List<AssetEntity>>(builder: (_) => picker),
     );
+    AssetPicker.setInternalExceptionHandler(null);
     return result;
   }
 
@@ -138,19 +143,22 @@ class AssetPickerDelegate {
     Key? key,
     bool useRootNavigator = true,
     AssetPickerPageRouteBuilder<List<Asset>>? pageRouteBuilder,
+    ExceptionHandler? internalExceptionHandler,
   }) async {
     await permissionCheck();
     final Widget picker = AssetPicker<Asset, Path>(
       key: key,
       builder: delegate,
     );
+    AssetPicker.setInternalExceptionHandler(internalExceptionHandler);
     final List<Asset>? result = await Navigator.of(
       context,
       rootNavigator: useRootNavigator,
     ).push<List<Asset>>(
       pageRouteBuilder?.call(picker) ??
           AssetPickerPageRoute<List<Asset>>(builder: (_) => picker),
     );
+    AssetPicker.setInternalExceptionHandler(null);
     return result;
   }
 
@@ -165,8 +173,8 @@ class AssetPickerDelegate {
     try {
       PhotoManager.addChangeCallback(callback);
       PhotoManager.startChangeNotify();
-    } catch (e) {
-      realDebugPrint('Error when registering assets callback: $e');
+    } catch (e, s) {
+      handleException(e, s);
     }
   }
 
@@ -181,8 +189,8 @@ class AssetPickerDelegate {
     try {
       PhotoManager.removeChangeCallback(callback);
       PhotoManager.stopChangeNotify();
-    } catch (e) {
-      realDebugPrint('Error when unregistering assets callback: $e');
+    } catch (e, s) {
+      handleException(e, s);
     }
   }
 

lib/src/internal/methods.dart

@@ -6,10 +6,36 @@ import 'dart:developer';
 
 import 'package:flutter/foundation.dart';
 
+import '../constants/typedefs.dart';
+import 'singleton.dart';
+
 /// Log only when debugging.
 /// 只在调试模式打印
 void realDebugPrint(dynamic message) {
   if (!kReleaseMode) {
-    log('$message');
+    log('[wechat_assets_picker] $message');
+  }
+}
+
+/// @nodoc
+void handleException(Object e, StackTrace s) {
+  final ExceptionHandler? handler = Singleton.internalExceptionHandler;
+  if (handler == null) {
+    FlutterError.presentError(
+      FlutterErrorDetails(
+        exception: e,
+        stack: s,
+        library: 'wechat_assets_picker',
+        silent: true,
+        informationCollector: () => <DiagnosticsNode>[
+          ErrorHint(
+            'Note: Use `AssetPickerConfig.internalExceptionHandler` '
+            'to handle exceptions manually.',
+          ),
+        ],
+      ),
+    );
+  } else {
+    handler(e, s);
   }
 }

lib/src/internal/singleton.dart

@@ -4,19 +4,21 @@
 
 import 'package:flutter/widgets.dart';
 
+import '../constants/typedefs.dart';
 import '../delegates/asset_picker_text_delegate.dart';
 import '../delegates/sort_path_delegate.dart';
 
 /// Define an inner static singleton for picker libraries.
 class Singleton {
   const Singleton._();
 
+  static ExceptionHandler? internalExceptionHandler;
   static AssetPickerTextDelegate textDelegate = const AssetPickerTextDelegate();
   static SortPathDelegate<dynamic> sortPathDelegate = SortPathDelegate.common;
 
   /// The last scroll position where the picker scrolled.
   ///
   /// See also:
-  ///  * [AssetPickerBuilderDelegate.keepScrollOffset]
+  ///  * [DefaultAssetPickerBuilderDelegate.keepScrollOffset]
   static ScrollPosition? scrollPosition;
 }

lib/src/provider/asset_picker_provider.dart

@@ -12,6 +12,7 @@ import 'package:provider/provider.dart';
 
 import '../constants/constants.dart';
 import '../delegates/sort_path_delegate.dart';
+import '../internal/methods.dart';
 import '../internal/singleton.dart';
 import '../models/path_wrapper.dart';
 
@@ -245,7 +246,7 @@ class DefaultAssetPickerProvider
     Future<void>.delayed(initializeDelayDuration, () async {
       await getPaths();
       await getAssetsFromCurrentPath();
-    });
+    }).catchError(handleException);
   }
 
   @visibleForTesting
@@ -414,40 +415,50 @@ class DefaultAssetPickerProvider
   Future<Uint8List?> getThumbnailFromPath(
     PathWrapper<AssetPathEntity> path,
   ) async {
-    if (requestType == RequestType.audio) {
-      return null;
-    }
-    final int assetCount = path.assetCount ?? await path.path.assetCountAsync;
-    if (assetCount == 0) {
-      return null;
-    }
-    final List<AssetEntity> assets = await path.path.getAssetListRange(
-      start: 0,
-      end: 1,
-    );
-    if (assets.isEmpty) {
-      return null;
-    }
-    final AssetEntity asset = assets.single;
-    // Obtain the thumbnail only when the asset is image or video.
-    if (asset.type != AssetType.image && asset.type != AssetType.video) {
+    try {
+      if (requestType == RequestType.audio) {
+        return null;
+      }
+      final int assetCount = path.assetCount ?? await path.path.assetCountAsync;
+      if (assetCount == 0) {
+        return null;
+      }
+      final List<AssetEntity> assets = await path.path.getAssetListRange(
+        start: 0,
+        end: 1,
+      );
+      if (assets.isEmpty) {
+        return null;
+      }
+      final AssetEntity asset = assets.single;
+      // Obtain the thumbnail only when the asset is image or video.
+      if (asset.type != AssetType.image && asset.type != AssetType.video) {
+        return null;
+      }
+      final Uint8List? data = await asset.thumbnailDataWithSize(
+        pathThumbnailSize,
+      );
+      final int index = _paths.indexWhere(
+        (PathWrapper<AssetPathEntity> p) => p.path == path.path,
+      );
+      if (index != -1) {
+        _paths[index] = _paths[index].copyWith(thumbnailData: data);
+        notifyListeners();
+      }
+      return data;
+    } catch (e, s) {
+      handleException(e, s);
       return null;
     }
-    final Uint8List? data = await asset.thumbnailDataWithSize(
-      pathThumbnailSize,
-    );
-    final int index = _paths.indexWhere(
-      (PathWrapper<AssetPathEntity> p) => p.path == path.path,
-    );
-    if (index != -1) {
-      _paths[index] = _paths[index].copyWith(thumbnailData: data);
-      notifyListeners();
-    }
-    return data;
   }
 
   Future<void> getAssetCountFromPath(PathWrapper<AssetPathEntity> path) async {
-    final int assetCount = await path.path.assetCountAsync;
+    final int assetCount = await path.path.assetCountAsync.catchError(
+      (Object e, StackTrace s) {
+        handleException(e, s);
+        return 0;
+      },
+    );
     final int index = _paths.indexWhere(
       (PathWrapper<AssetPathEntity> p) => p == path,
     );

lib/src/widget/asset_picker.dart

@@ -7,8 +7,11 @@ import 'package:flutter/services.dart';
 import 'package:photo_manager/photo_manager.dart';
 
 import '../constants/config.dart';
+import '../constants/typedefs.dart';
 import '../delegates/asset_picker_builder_delegate.dart';
 import '../delegates/asset_picker_delegate.dart';
+import '../internal/methods.dart';
+import '../internal/singleton.dart';
 import '../provider/asset_picker_provider.dart';
 import 'asset_picker_page_route.dart';
 
@@ -19,6 +22,11 @@ class AssetPicker<Asset, Path> extends StatefulWidget {
 
   final AssetPickerBuilderDelegate<Asset, Path> builder;
 
+  /// Update the internal exception handler to the given [exceptionHandler].
+  static void setInternalExceptionHandler(ExceptionHandler? exceptionHandler) {
+    Singleton.internalExceptionHandler = exceptionHandler;
+  }
+
   /// Provide another [AssetPickerDelegate] which override with
   /// custom methods during handling the picking,
   /// e.g. to verify if arguments are properly set during picking calls.
@@ -124,7 +132,7 @@ class AssetPickerState<Asset, Path> extends State<AssetPicker<Asset, Path>>
       if (mounted) {
         setState(() {});
       }
-    });
+    }).catchError(handleException);
   }
 
   @override

lib/src/widget/builder/audio_page_builder.dart

@@ -53,7 +53,7 @@ class _AudioPageBuilderState extends State<AudioPageBuilder> {
   @override
   void initState() {
     super.initState();
-    openAudioFile();
+    openAudioFile().catchError(handleException);
   }
 
   @override
@@ -76,8 +76,6 @@ class _AudioPageBuilderState extends State<AudioPageBuilder> {
       _controller = VideoPlayerController.network(url!);
       await _controller.initialize();
       _controller.addListener(audioPlayerListener);
-    } catch (e) {
-      realDebugPrint('Error when opening audio file: $e');
     } finally {
       isLoaded = true;
       if (mounted) {

lib/src/widget/builder/image_page_builder.dart

@@ -11,6 +11,7 @@ import 'package:photo_manager/photo_manager.dart';
 import 'package:video_player/video_player.dart';
 
 import '../../delegates/asset_picker_viewer_builder_delegate.dart';
+import '../../internal/methods.dart';
 import 'locally_available_builder.dart';
 
 class ImagePageBuilder extends StatefulWidget {
@@ -57,12 +58,12 @@ class _ImagePageBuilderState extends State<ImagePageBuilder> {
     if (!mounted || file == null) {
       return;
     }
-    final VideoPlayerController c = VideoPlayerController.file(
+    final VideoPlayerController controller = VideoPlayerController.file(
       file,
       videoPlayerOptions: VideoPlayerOptions(mixWithOthers: true),
     );
-    setState(() => _controller = c);
-    c
+    setState(() => _controller = controller);
+    controller
       ..initialize()
       ..setVolume(0)
       ..addListener(() {
@@ -159,7 +160,7 @@ class _ImagePageBuilderState extends State<ImagePageBuilder> {
         // Initialize the video controller when the asset is a Live photo
         // and available for further use.
         if (!_isLocallyAvailable && _isLivePhoto) {
-          _initializeLivePhoto();
+          _initializeLivePhoto().catchError(handleException);
         }
         _isLocallyAvailable = true;
         // TODO(Alex): Wait until `extended_image` support synchronized zooming.

lib/src/widget/builder/locally_available_builder.dart

@@ -35,7 +35,7 @@ class _LocallyAvailableBuilderState extends State<LocallyAvailableBuilder> {
   @override
   void initState() {
     super.initState();
-    _checkLocallyAvailable();
+    _checkLocallyAvailable().catchError(handleException);
   }
 
   Future<void> _checkLocallyAvailable() async {
@@ -61,7 +61,7 @@ class _LocallyAvailableBuilderState extends State<LocallyAvailableBuilder> {
             setState(() {});
           }
         }
-      });
+      }).catchError(handleException);
     }
     _progressHandler?.stream.listen((PMProgressState s) {
       realDebugPrint('Handling progress: $s.');
@@ -70,6 +70,8 @@ class _LocallyAvailableBuilderState extends State<LocallyAvailableBuilder> {
         if (mounted) {
           setState(() {});
         }
+      } else if (s.state == PMRequestState.failed) {
+        handleException(s, StackTrace.current);
       }
     });
   }