Android“Top Sheet”相当于“Bottom Sheet”？

Question

我想要实现一种“Bottom Sheet”类型的布局，但有一个扭曲，其中“底部”工作表将是一个MapFragment，它不能很好地作为向上/向下可拖动视图。

我有一个天真的想法是将逻辑“翻转”到“Top Sheet”设计，你可以向上/向下拖动Top Sheet以显示更多/更少的底部MapFragment。

即：从这......

......到[类似]这......

这有可能是支持设计工具，还是我必须自己滚动这样的东西？

Answer 1

这个TopSheetBehavior实现（https://github.com/MedveDomg/AndroidTopSheet/blob/master/library/src/main/java/com/github/techisfun/android/topsheet/TopSheetBehavior.java）已证明在我的情况下工作得很好。我发现许多其他TopSheetBehavior不完整或崩溃，但这个没有崩溃，只通过替换行为参数开箱即用：

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:behavior_hideable="true"
        app:behavior_peekHeight="56dp"
        app:layout_behavior="your.package.components.TopSheetBehavior">

        <!-- Your content goes here -->

    </LinearLayout>

Answer 2

以上是我在上面评论过的解决方案的基础。我会回来然后把它充实。

@Override
protected void onCreate(
        @Nullable
                Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    if (isFinishing())
    {
        return;
    }


    setContentView(R.layout.activity_home);

    ...

    mGroupBottomSheetFiller = (ViewGroup) findViewById(R.id.groupBottomSheetFiller);

    final NestedScrollView bottomSheetMap = (NestedScrollView) findViewById(R.id.bottomSheetMap);
    mBottomSheetMapBehavior = BottomSheetBehavior.from(bottomSheetMap);
    mBottomSheetMapBehavior.setBottomSheetCallback(new BottomSheetCallback()
    {
        @Override
        public void onStateChanged(
                @NonNull
                        View bottomSheet,
                int newState)
        {
            //Log.e(TAG, "mBottomSheetMapBehavior.onStateChanged(bottomSheet, newState=" +
            //             bottomSheetBehaviorStateToString(newState) + ')');
            int visibility = isBottomSheetExpanded(mBottomSheetMapBehavior) ? View.VISIBLE : View.GONE;
            mImageBottomSheetMapClose.setVisibility(visibility);
        }

        @Override
        public void onSlide(
                @NonNull
                        View bottomSheet,
                float slideOffset)
        {
            //Log.e(TAG, "mBottomSheetMapBehavior.onStateChanged(bottomSheet, slideOffset=" + slideOffset + ')');
            resizeMap();
        }
    });
    bottomSheetMap.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener()
    {
        @Override
        public void onGlobalLayout()
        {
            //Log.e(TAG, "onGlobalLayout()");
            bottomSheetMap.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            resizeMap();
        }
    });

    ...
}

private void resizeMap()
{
    int screenHeightPixels = PbPlatformUtils.getScreenHeightPixels();
    //Log.e(TAG, "resizeMap: screenHeightPixels=" + screenHeightPixels);

    int[] location = new int[2];
    mGroupMap.getLocationInWindow(location);
    //Log.e(TAG, "resizeMap: getLocationInWindow=" + Arrays.toString(location));

    LayoutParams groupMapLayoutParams = mGroupMap.getLayoutParams();
    groupMapLayoutParams.height = screenHeightPixels - location[1];
    mGroupMap.requestLayout();
}

public static String bottomSheetBehaviorStateToString(int state)
{
    String s;
    switch (state)
    {
        case BottomSheetBehavior.STATE_COLLAPSED:
            s = "STATE_COLLAPSED";
            break;
        case BottomSheetBehavior.STATE_DRAGGING:
            s = "STATE_DRAGGING";
            break;
        case BottomSheetBehavior.STATE_EXPANDED:
            s = "STATE_EXPANDED";
            break;
        case BottomSheetBehavior.STATE_HIDDEN:
            s = "STATE_HIDDEN";
            break;
        case BottomSheetBehavior.STATE_SETTLING:
            s = "STATE_SETTLING";
            break;
        default:
            s = "UNKNOWN";
            break;
    }
    return s + '(' + state + ')';
}

private static boolean isBottomSheetExpanded(
        @NonNull
                BottomSheetBehavior bottomSheetBehavior)
{
    return bottomSheetBehavior.getState() == BottomSheetBehavior.STATE_EXPANDED;
}

private void bottomSheetMapExpand()
{
    mGroupBottomSheetFiller.setVisibility(View.VISIBLE);
    int peekHeightPx = getResources().getDimensionPixelSize(R.dimen.home_bottom_sheet_map_peek_height);
    mBottomSheetMapBehavior.setPeekHeight(peekHeightPx);
    mBottomSheetMapBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
    mBottomSheetMapBehavior.setHideable(false);
}

private void bottomSheetMapCollapse()
{
    mGroupBottomSheetFiller.setVisibility(View.VISIBLE);
    int peekHeightPx = getResources().getDimensionPixelSize(R.dimen.home_bottom_sheet_map_peek_height);
    mBottomSheetMapBehavior.setPeekHeight(peekHeightPx);
    mBottomSheetMapBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
    mBottomSheetMapBehavior.setHideable(false);
}

private void bottomSheetMapHide()
{
    mBottomSheetMapBehavior.setHideable(true);
    mBottomSheetMapBehavior.setPeekHeight(0);
    mBottomSheetMapBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
    mGroupBottomSheetFiller.setVisibility(View.GONE);
}