Include image dimensions & url in Image's onLoad callback

Summary:
This is similar to the iOS feature that was implemented by 84f68c3.

**Test plan (required)**

Verified that the image dimensions are included in the `onLoad` callback in a test app. Also, this change is used in my team's app.

Adam Comella
Microsoft Corp.
Closes #9608

Differential Revision: D3797659

Pulled By: foghina

fbshipit-source-id: ea83a907bf6b0b61d9bc1e90fc7c64b7132db81f

ReactAndroid/src/main/java/com/facebook/react/views/image/ImageLoadEvent.java

@@ -36,22 +36,32 @@ public class ImageLoadEvent extends Event<ImageLoadEvent> {
 
   private final int mEventType;
   private final @Nullable String mImageUri;
+  private final int mWidth;
+  private final int mHeight;
 
   public ImageLoadEvent(int viewId, @ImageEventType int eventType) {
     this(viewId, eventType, null);
   }
 
+  public ImageLoadEvent(int viewId, @ImageEventType int eventType, String imageUri) {
+    this(viewId, eventType, imageUri, 0, 0);
+  }
+
   public ImageLoadEvent(
     int viewId,
     @ImageEventType int eventType,
-    @Nullable String imageUri) {
+    @Nullable String imageUri,
+    int width,
+    int height) {
     super(viewId);
     mEventType = eventType;
     mImageUri = imageUri;
+    mWidth = width;
+    mHeight = height;
   }
 
   public static String eventNameForType(@ImageEventType int eventType) {
-    switch(eventType) {
+    switch (eventType) {
       case ON_ERROR:
         return "topError";
       case ON_LOAD:
@@ -82,10 +92,25 @@ public short getCoalescingKey() {
   @Override
   public void dispatch(RCTEventEmitter rctEventEmitter) {
     WritableMap eventData = null;
-    if (mImageUri != null) {
+
+    if (mImageUri != null || mEventType == ON_LOAD) {
       eventData = Arguments.createMap();
-      eventData.putString("uri", mImageUri);
+
+      if (mImageUri != null) {
+        eventData.putString("uri", mImageUri);
+      }
+
+      if (mEventType == ON_LOAD) {
+        WritableMap source = Arguments.createMap();
+        source.putDouble("width", mWidth);
+        source.putDouble("height", mHeight);
+        if (mImageUri != null) {
+          source.putString("url", mImageUri);
+        }
+        eventData.putMap("source", source);
+      }
     }
+
     rctEventEmitter.receiveEvent(getViewTag(), getEventName(), eventData);
   }
 }

ReactAndroid/src/main/java/com/facebook/react/views/image/ReactImageView.java

@@ -201,7 +201,8 @@ public void onFinalImageSet(
             @Nullable Animatable animatable) {
           if (imageInfo != null) {
             mEventDispatcher.dispatchEvent(
-              new ImageLoadEvent(getId(), ImageLoadEvent.ON_LOAD));
+              new ImageLoadEvent(getId(), ImageLoadEvent.ON_LOAD,
+                mImageSource.getSource(), imageInfo.getWidth(), imageInfo.getHeight()));
             mEventDispatcher.dispatchEvent(
               new ImageLoadEvent(getId(), ImageLoadEvent.ON_LOAD_END));
           }