refactor out RootView tag number logic

Reviewed By: achen1

Differential Revision: D5609280

fbshipit-source-id: bc0c9f50b2938f05d5e43f50491ff6f0de154fb6

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -930,7 +930,6 @@ public class ReactInstanceManager {
     Systrace.beginSection(TRACE_TAG_REACT_JAVA_BRIDGE, "attachRootViewToInstance");
     UIManagerModule uiManagerModule = catalystInstance.getNativeModule(UIManagerModule.class);
     final int rootTag = uiManagerModule.addRootView(rootView);
-    rootView.setRootViewTag(rootTag);
     rootView.runApplication();
     Systrace.beginAsyncSection(
       TRACE_TAG_REACT_JAVA_BRIDGE,

ReactAndroid/src/main/java/com/facebook/react/ReactRootView.java

@@ -41,8 +41,10 @@ import com.facebook.react.modules.deviceinfo.DeviceInfoModule;
 import com.facebook.react.uimanager.DisplayMetricsHolder;
 import com.facebook.react.uimanager.JSTouchDispatcher;
 import com.facebook.react.uimanager.PixelUtil;
+import com.facebook.react.uimanager.ReactRootViewTagGenerator;
 import com.facebook.react.uimanager.RootView;
 import com.facebook.react.uimanager.SizeMonitoringFrameLayout;
+import com.facebook.react.uimanager.TaggedRootView;
 import com.facebook.react.uimanager.UIManagerModule;
 import com.facebook.react.uimanager.events.EventDispatcher;
 import com.facebook.systrace.Systrace;
@@ -50,19 +52,17 @@ import javax.annotation.Nullable;
 
 /**
  * Default root view for catalyst apps. Provides the ability to listen for size changes so that a UI
- * manager can re-layout its elements.
+ * manager can re-layout its elements. It delegates handling touch events for itself and child views
- * It delegates handling touch events for itself and child views and sending those events to JS by
+ * and sending those events to JS by using JSTouchDispatcher. This view is overriding {@link
- * using JSTouchDispatcher.
+ * ViewGroup#onInterceptTouchEvent} method in order to be notified about the events for all of its
- * This view is overriding {@link ViewGroup#onInterceptTouchEvent} method in order to be notified
+ * children and it's also overriding {@link ViewGroup#requestDisallowInterceptTouchEvent} to make
- * about the events for all of its children and it's also overriding
+ * sure that {@link ViewGroup#onInterceptTouchEvent} will get events even when some child view start
- * {@link ViewGroup#requestDisallowInterceptTouchEvent} to make sure that
+ * intercepting it. In case when no child view is interested in handling some particular touch event
- * {@link ViewGroup#onInterceptTouchEvent} will get events even when some child view start
+ * this view's {@link View#onTouchEvent} will still return true in order to be notified about all
- * intercepting it. In case when no child view is interested in handling some particular
+ * subsequent touch events related to that gesture (in case when JS code want to handle that
- * touch event this view's {@link View#onTouchEvent} will still return true in order to be notified
+ * gesture).
- * about all subsequent touch events related to that gesture (in case when JS code want to handle
- * that gesture).
  */
-public class ReactRootView extends SizeMonitoringFrameLayout implements RootView {
+public class ReactRootView extends SizeMonitoringFrameLayout implements RootView, TaggedRootView {
 
   /**
    * Listener interface for react root view events
@@ -79,7 +79,7 @@ public class ReactRootView extends SizeMonitoringFrameLayout implements RootView
   private @Nullable Bundle mAppProperties;
   private @Nullable CustomGlobalLayoutListener mCustomGlobalLayoutListener;
   private @Nullable ReactRootViewEventListener mRootViewEventListener;
-  private int mRootViewTag;
+  private int mRootViewTag = ReactRootViewTagGenerator.getNextRootViewTag();
   private boolean mIsAttachedToInstance;
   private boolean mContentAppeared;
   private final JSTouchDispatcher mJSTouchDispatcher = new JSTouchDispatcher(this);
@@ -261,6 +261,7 @@ public class ReactRootView extends SizeMonitoringFrameLayout implements RootView
     if (mReactInstanceManager != null && mIsAttachedToInstance) {
       mReactInstanceManager.detachRootView(this);
       mIsAttachedToInstance = false;
+      mRootViewTag = ReactRootViewTagGenerator.getNextRootViewTag();
     }
   }
 
@@ -363,14 +364,11 @@ public class ReactRootView extends SizeMonitoringFrameLayout implements RootView
         "the onDestroyView() of your hosting Fragment.");
   }
 
+  @Override
   public int getRootViewTag() {
     return mRootViewTag;
   }
 
-  public void setRootViewTag(int rootViewTag) {
-    mRootViewTag = rootViewTag;
-  }
-
   private class CustomGlobalLayoutListener implements ViewTreeObserver.OnGlobalLayoutListener {
     private final Rect mVisibleViewArea;
     private final int mMinKeyboardHeightDetected;

ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactRootViewTagGenerator.java

@@ -0,0 +1,19 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.react.uimanager;
+
+/** Incremental counter for React Root View tag. */
+public class ReactRootViewTagGenerator {
+
+  // Keep in sync with ReactIOSTagHandles JS module - see that file for an explanation on why the
+  // increment here is 10.
+  private static final int ROOT_VIEW_TAG_INCREMENT = 10;
+
+  private static int sNextRootViewTag = 1;
+
+  public static synchronized int getNextRootViewTag() {
+    final int tag = sNextRootViewTag;
+    sNextRootViewTag += ROOT_VIEW_TAG_INCREMENT;
+    return tag;
+  }
+}

ReactAndroid/src/main/java/com/facebook/react/uimanager/TaggedRootView.java

@@ -0,0 +1,9 @@
+// Copyright 2004-present Facebook. All Rights Reserved.
+
+package com.facebook.react.uimanager;
+
+/** Interface for the a ReactRootView with a tag. */
+public interface TaggedRootView {
+
+  int getRootViewTag();
+}

ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java

@@ -9,15 +9,11 @@
 
 package com.facebook.react.uimanager;
 
-import javax.annotation.Nullable;
+import static com.facebook.react.bridge.ReactMarkerConstants.CREATE_UI_MANAGER_MODULE_CONSTANTS_END;
-
+import static com.facebook.react.bridge.ReactMarkerConstants.CREATE_UI_MANAGER_MODULE_CONSTANTS_START;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
 
 import android.content.ComponentCallbacks2;
 import android.content.res.Configuration;
-
 import com.facebook.common.logging.FLog;
 import com.facebook.react.animation.Animation;
 import com.facebook.react.bridge.Callback;
@@ -37,9 +33,10 @@ import com.facebook.react.uimanager.debug.NotThreadSafeViewHierarchyUpdateDebugL
 import com.facebook.react.uimanager.events.EventDispatcher;
 import com.facebook.systrace.Systrace;
 import com.facebook.systrace.SystraceMessage;
-
+import java.util.HashMap;
-import static com.facebook.react.bridge.ReactMarkerConstants.CREATE_UI_MANAGER_MODULE_CONSTANTS_END;
+import java.util.List;
-import static com.facebook.react.bridge.ReactMarkerConstants.CREATE_UI_MANAGER_MODULE_CONSTANTS_START;
+import java.util.Map;
+import javax.annotation.Nullable;
 
   /**
  * <p>Native module to allow JS to create and update native Views.</p>
@@ -76,9 +73,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
 
   protected static final String NAME = "UIManager";
 
-  // Keep in sync with ReactIOSTagHandles JS module - see that file for an explanation on why the
-  // increment here is 10
-  private static final int ROOT_VIEW_TAG_INCREMENT = 10;
   private static final boolean DEBUG = false;
 
   private final EventDispatcher mEventDispatcher;
@@ -86,7 +80,6 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
   private final UIImplementation mUIImplementation;
   private final MemoryTrimCallback mMemoryTrimCallback = new MemoryTrimCallback();
 
-  private int mNextRootViewTag = 1;
   private int mBatchId = 0;
 
   public UIManagerModule(
@@ -188,8 +181,7 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
     Systrace.beginSection(
       Systrace.TRACE_TAG_REACT_JAVA_BRIDGE,
       "UIManagerModule.addRootView");
-    final int tag = mNextRootViewTag;
+    final int tag = ((TaggedRootView) rootView).getRootViewTag();
-    mNextRootViewTag += ROOT_VIEW_TAG_INCREMENT;
 
     final int width;
     final int height;