From 663df57c6206105f8228ee3c57c46235837f6a4b Mon Sep 17 00:00:00 2001
From: Swordsman-Inaction <ipzlkmy@gmail.com>
Date: Tue, 23 May 2017 10:54:39 -0700
Subject: [PATCH] Add viewIsDescendantOf for UIManager on Android

Summary:
Add the ability for UIManager to check if a node is an ancestor of anther one on Android like #7876 did on iOS
Closes https://github.com/facebook/react-native/pull/13129

Differential Revision: D4938319

Pulled By: hramos

fbshipit-source-id: abe20779be2142a1ea9ac46f52d8cd8609236419
---
 .../react/uimanager/ReactShadowNode.java        | 17 +++++++++++++++++
 .../react/uimanager/UIImplementation.java       | 16 ++++++++++++++++
 .../react/uimanager/UIManagerModule.java        | 11 +++++++++++
 3 files changed, 44 insertions(+)

diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactShadowNode.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactShadowNode.java
index 3c8d92369..a3ce58bf3 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactShadowNode.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactShadowNode.java
@@ -452,6 +452,23 @@ public class ReactShadowNode {
     return mTotalNativeChildren;
   }
 
+  public boolean isDescendantOf(ReactShadowNode ancestorNode) {
+    ReactShadowNode parentNode = getParent();
+
+    boolean isDescendant = false;
+
+    while (parentNode != null) {
+      if (parentNode == ancestorNode) {
+        isDescendant = true;
+        break;
+      } else {
+        parentNode = parentNode.getParent();
+      }
+    }
+
+    return isDescendant;
+  }
+
   /**
    * Returns the offset within the native children owned by all layout-only nodes in the subtree
    * rooted at this node for the given child. Put another way, this returns the number of native
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java
index ab6e6f2aa..6fc29266f 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java
@@ -469,6 +469,22 @@ public class UIImplementation {
     mOperationsQueue.enqueueFindTargetForTouch(reactTag, targetX, targetY, callback);
   }
 
+  /**
+   *  Check if the first shadow node is the descendant of the second shadow node
+   */
+  public void viewIsDescendantOf(
+      final int reactTag,
+      final int ancestorReactTag,
+      final Callback callback) {
+    ReactShadowNode node = mShadowNodeRegistry.getNode(reactTag);
+    ReactShadowNode ancestorNode = mShadowNodeRegistry.getNode(ancestorReactTag);
+    if (node == null || ancestorNode == null) {
+      callback.invoke(false);
+      return;
+    }
+    callback.invoke(node.isDescendantOf(ancestorNode));
+  }
+
   /**
    * Determines the location on screen, width, and height of the given view relative to the root
    * view and returns the values via an async callback.
diff --git a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java
index c9074438f..e173b0795 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java
@@ -412,6 +412,17 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
       callback);
   }
 
+  /**
+   *  Check if the first shadow node is the descendant of the second shadow node
+   */
+  @ReactMethod
+  public void viewIsDescendantOf(
+      final int reactTag,
+      final int ancestorReactTag,
+      final Callback callback) {
+    mUIImplementation.viewIsDescendantOf(reactTag, ancestorReactTag, callback);
+  }
+
   /**
    * Registers a new Animation that can then be added to a View using {@link #addAnimation}.
    */