⚡️ Improve changes when limited on iOS (#615)

Author: AlexV525

CHANGELOG.md

@@ -9,6 +9,7 @@ that can be found in the LICENSE file. -->
 
 ## Unreleased
 
+- Improve changes when limited on iOS.
 - Use `LocallyAvailableBuilder` in the grid to provide better user awareness.
 
 ## 9.2.0

lib/src/delegates/asset_picker_builder_delegate.dart

@@ -4,7 +4,6 @@
 
 import 'dart:async';
 import 'dart:math' as math;
-import 'dart:typed_data' as typed_data;
 import 'dart:ui' as ui;
 
 import 'package:flutter/gestures.dart';
@@ -200,20 +199,24 @@ abstract class AssetPickerBuilderDelegate<Asset, Path> {
   /// 权限受限栏的高度
   double get permissionLimitedBarHeight => isPermissionLimited ? 75 : 0;
 
+  @Deprecated('Use permissionNotifier instead. This will be removed in 10.0.0')
+  ValueNotifier<PermissionState> get permission => permissionNotifier;
+
   /// Notifier for the current [PermissionState].
   /// 当前 [PermissionState] 的监听
-  late final ValueNotifier<PermissionState> permission =
-      ValueNotifier<PermissionState>(
+  late final permissionNotifier = ValueNotifier<PermissionState>(
     initialPermission,
   );
-  late final ValueNotifier<bool> permissionOverlayDisplay = ValueNotifier<bool>(
-    limitedPermissionOverlayPredicate?.call(permission.value) ??
-        (permission.value == PermissionState.limited),
+
+  late final permissionOverlayDisplay = ValueNotifier<bool>(
+    limitedPermissionOverlayPredicate?.call(permissionNotifier.value) ??
+        (permissionNotifier.value == PermissionState.limited),
   );
 
   /// Whether the permission is limited currently.
   /// 当前的权限是否为受限
-  bool get isPermissionLimited => permission.value == PermissionState.limited;
+  bool get isPermissionLimited =>
+      permissionNotifier.value == PermissionState.limited;
 
   bool effectiveShouldRevertGrid(BuildContext context) =>
       shouldRevertGrid ?? isAppleOS(context);
@@ -235,7 +238,7 @@ abstract class AssetPickerBuilderDelegate<Asset, Path> {
     Singleton.scrollPosition = null;
     gridScrollController.dispose();
     isSwitchingPath.dispose();
-    permission.dispose();
+    permissionNotifier.dispose();
     permissionOverlayDisplay.dispose();
   }
 
@@ -660,7 +663,7 @@ abstract class AssetPickerBuilderDelegate<Asset, Path> {
     );
 
     return ValueListenableBuilder2<PermissionState, bool>(
-      firstNotifier: permission,
+      firstNotifier: permissionNotifier,
       secondNotifier: permissionOverlayDisplay,
       builder: (_, PermissionState ps, bool isDisplay, __) {
         if (ps.isAuth || !isDisplay) {
@@ -850,11 +853,12 @@ class DefaultAssetPickerBuilderDelegate
 
   @override
   Future<void> onAssetsChanged(MethodCall call, StateSetter setState) async {
+    final permission = permissionNotifier.value;
+
     bool predicate() {
-      final p = permission.value;
       final path = provider.currentPath?.path;
       if (assetsChangeRefreshPredicate != null) {
-        return assetsChangeRefreshPredicate!(p, call, path);
+        return assetsChangeRefreshPredicate!(permission, call, path);
       }
       return path?.isAll == true;
     }
@@ -863,17 +867,22 @@ class DefaultAssetPickerBuilderDelegate
       return;
     }
 
-    assetsChangeCallback?.call(
-      permission.value,
-      call,
-      provider.currentPath?.path,
-    );
+    assetsChangeCallback?.call(permission, call, provider.currentPath?.path);
 
     final createIds = <String>[];
     final updateIds = <String>[];
     final deleteIds = <String>[];
+    int newCount = 0;
+    int oldCount = 0;
+
     // Typically for iOS.
     if (call.arguments case final Map arguments) {
+      if (arguments['newCount'] case final int count) {
+        newCount = count;
+      }
+      if (arguments['oldCount'] case final int count) {
+        oldCount = count;
+      }
       for (final e in (arguments['create'] as List?) ?? []) {
         if (e['id'] case final String id) {
           createIds.add(id);
@@ -889,7 +898,12 @@ class DefaultAssetPickerBuilderDelegate
           deleteIds.add(id);
         }
       }
-      if (createIds.isEmpty && updateIds.isEmpty && deleteIds.isEmpty) {
+      if (createIds.isEmpty &&
+          updateIds.isEmpty &&
+          deleteIds.isEmpty &&
+          // Updates with limited permission on iOS does not provide any IDs.
+          // Counting on length changes is not reliable.
+          (newCount == oldCount && permission != PermissionState.limited)) {
         return;
       }
     }
@@ -943,6 +957,7 @@ class DefaultAssetPickerBuilderDelegate
           ..totalAssetsCount = assetCount
           ..getThumbnailFromPath(newPathWrapper);
       }
+      isSwitchingPath.value = false;
     }).then(lock.complete).catchError(lock.completeError).whenComplete(() {
       onAssetsChangedLock = null;
     });
@@ -1782,7 +1797,7 @@ class DefaultAssetPickerBuilderDelegate
           mainAxisSize: MainAxisSize.min,
           children: <Widget>[
             ValueListenableBuilder<PermissionState>(
-              valueListenable: permission,
+              valueListenable: permissionNotifier,
               builder: (_, PermissionState ps, Widget? child) => Semantics(
                 label: '${semanticsTextDelegate.viewingLimitedAssetsTip}, '
                     '${semanticsTextDelegate.changeAccessibleLimitedAssets}',
@@ -1960,7 +1975,7 @@ class DefaultAssetPickerBuilderDelegate
   }) {
     final PathWrapper<AssetPathEntity> wrapper = list[index];
     final AssetPathEntity pathEntity = wrapper.path;
-    final typed_data.Uint8List? data = wrapper.thumbnailData;
+    final Uint8List? data = wrapper.thumbnailData;
 
     Widget builder() {
       if (data != null) {

lib/src/widget/asset_picker.dart

@@ -125,7 +125,7 @@ class AssetPickerState<Asset, Path> extends State<AssetPicker<Asset, Path>>
         if (!mounted) {
           return;
         }
-        widget.builder.permission.value = ps;
+        widget.builder.permissionNotifier.value = ps;
         if (ps == PermissionState.limited && Platform.isAndroid) {
           _onAssetsUpdated(const MethodCall(''));
         }