appBar method

Widget appBar(BuildContext context)

AppBar widget. 顶栏部件

Implementation

Widget appBar(BuildContext context) {
  return ValueListenableBuilder<bool>(
    valueListenable: isDisplayingDetail,
    builder: (_, bool value, Widget? child) => AnimatedPositionedDirectional(
      duration: kThemeAnimationDuration,
      curve: Curves.easeInOut,
      top: value ? 0.0 : -(Screens.topSafeHeight + kToolbarHeight),
      start: 0.0,
      end: 0.0,
      height: Screens.topSafeHeight + kToolbarHeight,
      child: child!,
    ),
    child: Container(
      padding: EdgeInsetsDirectional.only(
        top: Screens.topSafeHeight,
        end: 12.0,
      ),
      color: themeData.canvasColor.withOpacity(0.85),
      child: Row(
        children: <Widget>[
          const BackButton(),
          if (!isAppleOS && specialPickerType == null)
            StreamBuilder<int>(
              initialData: currentIndex,
              stream: pageStreamController.stream,
              builder: (BuildContext _, AsyncSnapshot<int> snapshot) {
                return Text(
                  '${snapshot.data! + 1}/${previewAssets.length}',
                  style: const TextStyle(
                    fontSize: 18.0,
                    fontWeight: FontWeight.bold,
                  ),
                );
              },
            ),
          const Spacer(),
          if (isAppleOS && provider != null) selectButton(context),
          if (!isAppleOS && (provider != null || isWeChatMoment))
            confirmButton(context),
        ],
      ),
    ),
  );
}