selectedBackdrop method

@override Widget selectedBackdrop(BuildContext context, int index, AssetEntity asset)

Animated backdrop widget for items. 部件选中时的动画遮罩部件

Implementation

@override
Widget selectedBackdrop(BuildContext context, int index, AssetEntity asset) {
  final double indicatorSize =
      MediaQuery.sizeOf(context).width / gridCount / 3;
  return Positioned.fill(
    child: GestureDetector(
      onTap: isPreviewEnabled ? () => viewAsset(context, index, asset) : null,
      child: Consumer<DefaultAssetPickerProvider>(
        builder: (_, DefaultAssetPickerProvider p, __) {
          final int index = p.selectedAssets.indexOf(asset);
          final bool selected = index != -1;
          return AnimatedContainer(
            duration: switchingPathDuration,
            padding: EdgeInsets.all(indicatorSize * .35),
            color: selected
                ? theme.colorScheme.primary.withOpacity(.45)
                : theme.colorScheme.background.withOpacity(.1),
            child: selected && !isSingleAssetMode
                ? Align(
                    alignment: AlignmentDirectional.topStart,
                    child: SizedBox(
                      height: indicatorSize / 2.5,
                      child: FittedBox(
                        alignment: AlignmentDirectional.topStart,
                        fit: BoxFit.cover,
                        child: Text(
                          '${index + 1}',
                          style: TextStyle(
                            color: theme.textTheme.bodyLarge?.color
                                ?.withOpacity(.75),
                            fontWeight: FontWeight.w600,
                            height: 1,
                          ),
                        ),
                      ),
                    ),
                  )
                : const SizedBox.shrink(),
          );
        },
      ),
    ),
  );
}