onAssetsChanged method

@override Future<void> onAssetsChanged(MethodCall call, StateSetter setState)

Called when assets changed and obtained notifications from the OS. 系统发出资源变更的通知时调用的方法

Implementation

@override
Future<void> onAssetsChanged(MethodCall call, StateSetter setState) async {
  if (!isPermissionLimited) {
    return;
  }
  isSwitchingPath.value = false;
  if (call.arguments is Map) {
    final Map<dynamic, dynamic> arguments =
        call.arguments as Map<dynamic, dynamic>;
    if (arguments['newCount'] == 0) {
      provider
        ..currentAssets = <AssetEntity>[]
        ..currentPath = null
        ..selectedAssets = <AssetEntity>[]
        ..hasAssetsToDisplay = false
        ..isAssetsEmpty = true
        ..totalAssetsCount = 0
        ..paths = [];
      return;
    }
  }
  await provider.getPaths();
  provider.currentPath = provider.paths.first;
  final PathWrapper<AssetPathEntity>? currentWrapper = provider.currentPath;
  if (currentWrapper != null) {
    final AssetPathEntity newPath =
        await currentWrapper.path.obtainForNewProperties();
    final int assetCount = await newPath.assetCountAsync;
    final PathWrapper<AssetPathEntity> newPathWrapper =
        PathWrapper<AssetPathEntity>(
      path: newPath,
      assetCount: assetCount,
    );
    provider
      ..currentPath = newPathWrapper
      ..hasAssetsToDisplay = assetCount != 0
      ..isAssetsEmpty = assetCount == 0
      ..totalAssetsCount = assetCount
      ..getThumbnailFromPath(newPathWrapper);
    if (newPath.isAll) {
      await provider.getAssetsFromCurrentPath();
      final List<AssetEntity> entitiesShouldBeRemoved = <AssetEntity>[];
      for (final AssetEntity entity in provider.selectedAssets) {
        if (!provider.currentAssets.contains(entity)) {
          entitiesShouldBeRemoved.add(entity);
        }
      }
      entitiesShouldBeRemoved.forEach(provider.selectedAssets.remove);
    }
  }
}