FAB和ListView的快速返回模式

Question

ViewPager中有一个简单的ListView，屏幕右下角有一个浮动操作栏。

我想实现快速返回模式，这样当我滚动ListView时，FAB会在屏幕上向下滚动，然后在相反的滚动上出现。

提前谢谢。

编辑：

list.setAdapter(new QuickReturnAdapter(adapter));
            quickReturnAttacher = QuickReturnAttacher.forView(list);
            quickReturnAttacher.addTargetView(floatMenu, AbsListViewScrollTarget.POSITION_BOTTOM, dpToPx(context, 400));
            if (quickReturnAttacher instanceof AbsListViewQuickReturnAttacher) {
                // This is the correct way to register an OnScrollListener.
                // You have to add it on the QuickReturnAttacher, instead
                // of on the viewGroup directly.
                final AbsListViewQuickReturnAttacher attacher = (AbsListViewQuickReturnAttacher) quickReturnAttacher;
                attacher.addOnScrollListener(new AbsListView.OnScrollListener() {
                    @Override
                    public void onScrollStateChanged(AbsListView view, int scrollState) {
                    }
                    @Override
                    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
                    }
                });
            }

然后我使用quickReturnAttacher.setOnItemClickListener，但这不起作用。

Answer 1

已有一个用于此功能的开源库。https://github.com/felipecsl/QuickReturn

试试这个：

    final AbsListViewQuickReturnAttacher attacher =   (AbsListViewQuickReturnAttacher) quickReturnAttacher;
    attacher.addOnScrollListener(this);
    attacher.setOnItemClickListener(this);
});

对我来说，这是有效的，回调中传递的位置是正确的。您必须将您的点击监听器注册到附件中，而不是列表中。

如何在类AbsListViewQuickReturnAttacher中找不到方法setOnItemClickListener？

Answer 2

您可以为ListViews:的快速返回模式尝试此解决方案

yourListView.setOnScrollListener(new AbsListView.OnScrollListener() {
         @SuppressLint("NewApi")
         @Override
         public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
            int scrollOffset = 0;
            float transitionY;
            if (firstVisibleItem > 0) {
               scrollOffset += headerHeight;
               if (firstVisibleItem > 1) {
                  scrollOffset += (firstVisibleItem - 1) * cellHeight;
               }
            }
            if (yourListView.getChildCount() > 0) {
               scrollOffset += -yourListView.getChildAt(0).getTop();
               scrollOffset = -scrollOffset;
            }
            float scrollDelta = scrollOffset - prevOffset;
            float nextY = mQuickReturnView.getY() + scrollDelta;
            if (nextY < minRawY) {
               transitionY = minRawY;
            }
            else if (nextY > qReturnDelta) {
               transitionY = qReturnDelta;
            }
            else {
               transitionY = nextY;
            }
            mQuickReturnView.setY(transitionY);
            prevOffset = scrollOffset;
         }
         @Override
         public void onScrollStateChanged(AbsListView view, int scrollState) {
         }
      });