From a10a510d968b3068dd2f8923b9abdaf012c62040 Mon Sep 17 00:00:00 2001
From: Felix Oghina <foghina@fb.com>
Date: Fri, 15 Jan 2016 09:46:34 -0800
Subject: [PATCH] support removeClippedSubviews in ReactHorizontalScrollView

Reviewed By: andreicoman11

Differential Revision: D2831013

fb-gh-sync-id: 2ac4eb8d748f2d66523992e8683c1b4d60198ba1
---
 .../scroll/ReactHorizontalScrollView.java     | 61 ++++++++++++++++++-
 .../ReactHorizontalScrollViewManager.java     |  7 +++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java b/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java
index 298512c6d..c8bdc978a 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java
@@ -9,29 +9,54 @@
 
 package com.facebook.react.views.scroll;
 
+import javax.annotation.Nullable;
+
 import android.content.Context;
+import android.graphics.Rect;
 import android.view.MotionEvent;
+import android.view.View;
 import android.widget.HorizontalScrollView;
 
+import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.uimanager.MeasureSpecAssertions;
 import com.facebook.react.uimanager.events.NativeGestureUtil;
+import com.facebook.react.views.view.ReactClippingViewGroup;
+import com.facebook.react.views.view.ReactClippingViewGroupHelper;
 
 /**
  * Similar to {@link ReactScrollView} but only supports horizontal scrolling.
  */
-public class ReactHorizontalScrollView extends HorizontalScrollView {
+public class ReactHorizontalScrollView extends HorizontalScrollView implements
+    ReactClippingViewGroup {
 
   private final OnScrollDispatchHelper mOnScrollDispatchHelper = new OnScrollDispatchHelper();
 
+  private boolean mRemoveClippedSubviews;
   private boolean mSendMomentumEvents;
   private boolean mDragging;
   private boolean mFlinging;
   private boolean mDoneFlinging;
 
+  private @Nullable Rect mClippingRect;
+
   public ReactHorizontalScrollView(Context context) {
     super(context);
   }
 
+  @Override
+  public void setRemoveClippedSubviews(boolean removeClippedSubviews) {
+    if (removeClippedSubviews && mClippingRect == null) {
+      mClippingRect = new Rect();
+    }
+    mRemoveClippedSubviews = removeClippedSubviews;
+    updateClippingRect();
+  }
+
+  @Override
+  public boolean getRemoveClippedSubviews() {
+    return mRemoveClippedSubviews;
+  }
+
   public void setSendMomentumEvents(boolean sendMomentumEvents) {
     mSendMomentumEvents = sendMomentumEvents;
   }
@@ -56,9 +81,14 @@ public class ReactHorizontalScrollView extends HorizontalScrollView {
     super.onScrollChanged(x, y, oldX, oldY);
 
     if (mOnScrollDispatchHelper.onScrollChanged(x, y)) {
+      if (mRemoveClippedSubviews) {
+        updateClippingRect();
+      }
+
       if (mFlinging) {
         mDoneFlinging = false;
       }
+
       ReactScrollViewHelper.emitScrollEvent(this);
     }
   }
@@ -106,4 +136,33 @@ public class ReactHorizontalScrollView extends HorizontalScrollView {
       postOnAnimationDelayed(r, ReactScrollViewHelper.MOMENTUM_DELAY);
     }
   }
+
+
+  @Override
+  protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+    super.onSizeChanged(w, h, oldw, oldh);
+    if (mRemoveClippedSubviews) {
+      updateClippingRect();
+    }
+  }
+
+  @Override
+  public void updateClippingRect() {
+    if (!mRemoveClippedSubviews) {
+      return;
+    }
+
+    Assertions.assertNotNull(mClippingRect);
+
+    ReactClippingViewGroupHelper.calculateClippingRect(this, mClippingRect);
+    View contentView = getChildAt(0);
+    if (contentView instanceof ReactClippingViewGroup) {
+      ((ReactClippingViewGroup) contentView).updateClippingRect();
+    }
+  }
+
+  @Override
+  public void getClippingRect(Rect outClippingRect) {
+    outClippingRect.set(Assertions.assertNotNull(mClippingRect));
+  }
 }
diff --git a/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java b/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java
index 972a88acd..07a39d4a4 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java
@@ -15,6 +15,7 @@ import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.uimanager.annotations.ReactProp;
 import com.facebook.react.uimanager.ThemedReactContext;
 import com.facebook.react.uimanager.ViewGroupManager;
+import com.facebook.react.views.view.ReactClippingViewGroupHelper;
 
 /**
  * View manager for {@link ReactHorizontalScrollView} components.
@@ -38,6 +39,12 @@ public class ReactHorizontalScrollViewManager
     return new ReactHorizontalScrollView(context);
   }
 
+  @ReactProp(name = ReactClippingViewGroupHelper.PROP_REMOVE_CLIPPED_SUBVIEWS)
+  public void setRemoveClippedSubviews(ReactHorizontalScrollView view, boolean removeClippedSubviews) {
+    view.setRemoveClippedSubviews(removeClippedSubviews);
+  }
+
+
   @ReactProp(name = "showsHorizontalScrollIndicator")
   public void setShowsHorizontalScrollIndicator(ReactHorizontalScrollView view, boolean value) {
     view.setHorizontalScrollBarEnabled(value);