Implement hit slop.

Summary: Hitslop on RTCView both virtual and non-virtual.

Reviewed By: ahmedre

Differential Revision: D3693412

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

@@ -32,6 +32,7 @@ import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.bridge.ReactContext;
 import com.facebook.react.bridge.SoftAssertions;
 import com.facebook.react.touch.OnInterceptTouchEventListener;
+import com.facebook.react.touch.ReactHitSlopView;
 import com.facebook.react.touch.ReactInterceptingViewGroup;
 import com.facebook.react.uimanager.PointerEvents;
 import com.facebook.react.uimanager.ReactCompoundViewGroup;
@@ -48,7 +49,7 @@ import com.facebook.react.views.view.ReactClippingViewGroup;
  */
 /* package */ final class FlatViewGroup extends ViewGroup
     implements ReactInterceptingViewGroup, ReactClippingViewGroup,
-    ReactCompoundViewGroup, ReactPointerEventsView, FlatMeasuredViewGroup {
+    ReactCompoundViewGroup, ReactHitSlopView, ReactPointerEventsView, FlatMeasuredViewGroup {
   /**
    * Helper class that allows AttachDetachListener to invalidate the hosting View.
    */
@@ -109,6 +110,8 @@ import com.facebook.react.views.view.ReactClippingViewGroup;
   private static final ArrayList<View> EMPTY_DETACHED_VIEWS = new ArrayList<>(0);
   private @Nullable DrawCommandManager mDrawCommandManager;
 
+  private @Nullable Rect mHitSlopRect;
+
   /* package */ FlatViewGroup(Context context) {
     super(context);
     setClipChildren(false);
@@ -911,4 +914,13 @@ import com.facebook.react.views.view.ReactClippingViewGroup;
   public boolean getRemoveClippedSubviews() {
     return mDrawCommandManager != null;
   }
+
+  @Override
+  public @Nullable Rect getHitSlopRect() {
+    return mHitSlopRect;
+  }
+
+  public void setHitSlopRect(@Nullable Rect rect) {
+    mHitSlopRect = rect;
+  }
 }

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

@@ -35,6 +35,16 @@ package com.facebook.react.flat;
     mIsVirtual = isVirtual;
   }
 
+  /* package */ final boolean matches(
+      float left,
+      float top,
+      float right,
+      float bottom,
+      boolean isVirtual) {
+    return left == mLeft && top == mTop && bottom == mBottom && right == mRight &&
+        isVirtual == mIsVirtual;
+  }
+
   /* package */ final boolean withinBounds(float touchX, float touchY) {
       return mLeft <= touchX && touchX < mRight && mTop <= touchY && touchY < mBottom;
   }

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

@@ -11,6 +11,8 @@ package com.facebook.react.flat;
 
 import javax.annotation.Nullable;
 
+import android.graphics.Rect;
+
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.uimanager.PixelUtil;
 import com.facebook.react.uimanager.ReactStylesDiffMap;
@@ -18,6 +20,9 @@ import com.facebook.react.uimanager.ViewProps;
 import com.facebook.react.uimanager.annotations.ReactProp;
 import com.facebook.react.uimanager.annotations.ReactPropGroup;
 
+/**
+ * Node for a react View.
+ */
 /* package */ final class RCTView extends FlatShadowNode {
 
   private @Nullable DrawBorder mDrawBorder;
@@ -25,6 +30,8 @@ import com.facebook.react.uimanager.annotations.ReactPropGroup;
   boolean mRemoveClippedSubviews;
   boolean mHorizontal;
 
+  private @Nullable Rect mHitSlop;
+
   @Override
   /* package */ void handleUpdateProperties(ReactStylesDiffMap styles) {
     mRemoveClippedSubviews = mRemoveClippedSubviews ||
@@ -123,11 +130,43 @@ import com.facebook.react.uimanager.annotations.ReactPropGroup;
     getMutableBorder().setBorderStyle(borderStyle);
   }
 
+  @ReactProp(name = "hitSlop")
+  public void setHitSlop(@Nullable ReadableMap hitSlop) {
+    if (hitSlop == null) {
+      mHitSlop = null;
+    } else {
+      mHitSlop = new Rect(
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("left")),
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("top")),
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("right")),
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("bottom")));
+    }
+  }
+
   @ReactProp(name = "pointerEvents")
   public void setPointerEvents(@Nullable String pointerEventsStr) {
     forceMountToView();
   }
 
+  @Override
+  /* package */ void updateNodeRegion(
+      float left,
+      float top,
+      float right,
+      float bottom,
+      boolean isVirtual) {
+    if (mHitSlop != null) {
+      left -= mHitSlop.left;
+      top -= mHitSlop.top;
+      bottom += mHitSlop.bottom;
+      right += mHitSlop.right;
+    }
+
+    if (!getNodeRegion().matches(left, top, right, bottom, isVirtual)) {
+      setNodeRegion(new NodeRegion(left, top, right, bottom, getReactTag(), isVirtual));
+    }
+  }
+
   private DrawBorder getMutableBorder() {
     if (mDrawBorder == null) {
       mDrawBorder = new DrawBorder();

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

@@ -13,6 +13,7 @@ import javax.annotation.Nullable;
 
 import java.util.Map;
 
+import android.graphics.Rect;
 import android.os.Build;
 
 import com.facebook.react.bridge.JSApplicationIllegalArgumentException;
@@ -124,4 +125,18 @@ import com.facebook.react.views.view.ReactDrawableHelper;
     // default or invalid
     return PointerEvents.AUTO;
   }
+
+  @ReactProp(name = "hitSlop")
+  public void setHitSlop(FlatViewGroup view, @Nullable ReadableMap hitSlop) {
+    if (hitSlop == null) {
+      view.setHitSlopRect(null);
+    } else {
+      view.setHitSlopRect(new Rect(
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("left")),
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("top")),
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("right")),
+          (int) PixelUtil.toPixelFromDIP(hitSlop.getDouble("bottom"))
+      ));
+    }
+  }
 }