Improve removeClippedSubviews for overflowing views

Summary:
Historically, removeClippedSubviews for Nodes would not clip views
that overflowed their parent. This patch changes that, so that Nodes can
properly clip views when they are off screen (even if they have descendants
that overflow the bounds of their parent).

This is done by calculating a set of offsets from the actual width and
height of the view, and using those in the clipping calculations.

Reviewed By: sriramramani

Differential Revision: D3409859

ReactAndroid/src/main/java/com/facebook/react/flat/FlatViewGroup.java

@@ -82,6 +82,7 @@ import com.facebook.react.views.view.ReactClippingViewGroupHelper;
 
   private static final ArrayList<FlatViewGroup> LAYOUT_REQUESTS = new ArrayList<>();
   private static final Rect VIEW_BOUNDS = new Rect();
+  private static final Rect EMPTY_RECT = new Rect();
 
   private @Nullable InvalidateCallback mInvalidateCallback;
   private DrawCommand[] mDrawCommands = DrawCommand.EMPTY_ARRAY;
@@ -101,8 +102,9 @@ import com.facebook.react.views.view.ReactClippingViewGroupHelper;
   // lookups in o(1) instead of o(log n) - trade space for time
   private final Map<Integer, DrawView> mDrawViewMap = new HashMap<>();
   private final Map<Integer, FlatViewGroup> mClippedSubviews = new HashMap<>();
-  // whether or not this FlatViewGroup has elements that overflow its bounds
-  private boolean mHasOverflowingElements;
+  // for overflow visible, these adjustments are what we can apply to know the actual bounds of
+  // a ViewGroup while taking overflowing elements into account.
+  private Rect mLogicalAdjustments = EMPTY_RECT;
 
   /* package */ FlatViewGroup(Context context) {
     super(context);
@@ -393,9 +395,9 @@ import com.facebook.react.views.view.ReactClippingViewGroupHelper;
     ++mDrawChildIndex;
   }
 
-  /* package */ void mountDrawCommands(DrawCommand[] drawCommands, boolean hasOverflowingElements) {
+  /* package */ void mountDrawCommands(DrawCommand[] drawCommands, Rect logicalAdjustments) {
     mDrawCommands = drawCommands;
-    mHasOverflowingElements = hasOverflowingElements;
+    mLogicalAdjustments = logicalAdjustments;
     if (mRemoveClippedSubviews) {
       mDrawViewMap.clear();
       for (DrawCommand drawCommand : mDrawCommands) {
@@ -602,10 +604,10 @@ import com.facebook.react.views.view.ReactClippingViewGroupHelper;
         if (flatViewGroup != null) {
           // invisible
           if (clippingRect.intersects(
-              flatViewGroup.getLeft(),
-              flatViewGroup.getTop(),
-              flatViewGroup.getRight(),
-              flatViewGroup.getBottom())) {
+              flatViewGroup.getLeft() + flatViewGroup.mLogicalAdjustments.left,
+              flatViewGroup.getTop() + flatViewGroup.mLogicalAdjustments.top,
+              flatViewGroup.getRight() + flatViewGroup.mLogicalAdjustments.right,
+              flatViewGroup.getBottom() + flatViewGroup.mLogicalAdjustments.bottom)) {
             // now on the screen
             attachViewToParent(
                 flatViewGroup,
@@ -623,12 +625,11 @@ import com.facebook.react.views.view.ReactClippingViewGroupHelper;
             Animation animation = flatChildView.getAnimation();
             boolean isAnimating = animation != null && !animation.hasEnded();
             if (!isAnimating &&
-                !flatChildView.mHasOverflowingElements &&
                 !clippingRect.intersects(
-                    view.getLeft(),
-                    view.getTop(),
-                    view.getRight(),
-                    view.getBottom())) {
+                    view.getLeft() + flatChildView.mLogicalAdjustments.left,
+                    view.getTop() + flatChildView.mLogicalAdjustments.top,
+                    view.getRight() + flatChildView.mLogicalAdjustments.right,
+                    view.getBottom() + flatChildView.mLogicalAdjustments.bottom)) {
               // now off the screen
               mClippedSubviews.put(view.getId(), flatChildView);
               detachViewFromParent(view);