Add surface size change callback to VideoListener.

This allows to detect changes in the surface size. SimpleExoPlayer already
has the necessary listeners to report size changes for all surfaces whose
lifecycle are managed by SimpleExoPlayer.

In a subsequent change, AnalyticsCollector can be registered as a
VideoListener to automatically notify of surface size changes.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=199605434

RELEASENOTES.md

@@ -17,6 +17,7 @@
   * Allow injection of custom playlist trackers.
 * Add method to `BandwidthMeter` to return the `TransferListener` used to gather
   bandwidth information.
+* Add callback to `VideoListener` to notify of surface size changes.
 
 ### 2.8.2 ###
 

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -16,6 +16,7 @@
 package com.google.android.exoplayer2;
 
 import android.annotation.TargetApi;
+import android.graphics.Rect;
 import android.graphics.SurfaceTexture;
 import android.media.MediaCodec;
 import android.media.PlaybackParams;
@@ -86,6 +87,8 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
   private int videoScalingMode;
   private SurfaceHolder surfaceHolder;
   private TextureView textureView;
+  private int surfaceWidth;
+  private int surfaceHeight;
   private DecoderCounters videoDecoderCounters;
   private DecoderCounters audioDecoderCounters;
   private int audioSessionId;
@@ -238,6 +241,8 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
   public void setVideoSurface(Surface surface) {
     removeSurfaceCallbacks();
     setVideoSurfaceInternal(surface, false);
+    int newSurfaceSize = surface == null ? 0 : C.LENGTH_UNSET;
+    maybeNotifySurfaceSizeChanged(/* width= */ newSurfaceSize, /* height= */ newSurfaceSize);
   }
 
   @Override
@@ -253,10 +258,18 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     this.surfaceHolder = surfaceHolder;
     if (surfaceHolder == null) {
       setVideoSurfaceInternal(null, false);
+      maybeNotifySurfaceSizeChanged(/* width= */ 0, /* height= */ 0);
     } else {
       surfaceHolder.addCallback(componentListener);
       Surface surface = surfaceHolder.getSurface();
-      setVideoSurfaceInternal(surface != null && surface.isValid() ? surface : null, false);
+      if (surface != null && surface.isValid()) {
+        setVideoSurfaceInternal(surface, /* ownsSurface= */ false);
+        Rect surfaceSize = surfaceHolder.getSurfaceFrame();
+        maybeNotifySurfaceSizeChanged(surfaceSize.width(), surfaceSize.height());
+      } else {
+        setVideoSurfaceInternal(/* surface= */ null, /* ownsSurface= */ false);
+        maybeNotifySurfaceSizeChanged(/* width= */ 0, /* height= */ 0);
+      }
     }
   }
 
@@ -283,6 +296,7 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     this.textureView = textureView;
     if (textureView == null) {
       setVideoSurfaceInternal(null, true);
+      maybeNotifySurfaceSizeChanged(/* width= */ 0, /* height= */ 0);
     } else {
       if (textureView.getSurfaceTextureListener() != null) {
         Log.w(TAG, "Replacing existing SurfaceTextureListener.");
@@ -290,7 +304,13 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
       textureView.setSurfaceTextureListener(componentListener);
       SurfaceTexture surfaceTexture = textureView.isAvailable() ? textureView.getSurfaceTexture()
           : null;
-      setVideoSurfaceInternal(surfaceTexture == null ? null : new Surface(surfaceTexture), true);
+      if (surfaceTexture == null) {
+        setVideoSurfaceInternal(/* surface= */ null, /* ownsSurface= */ true);
+        maybeNotifySurfaceSizeChanged(/* width= */ 0, /* height= */ 0);
+      } else {
+        setVideoSurfaceInternal(new Surface(surfaceTexture), /* ownsSurface= */ true);
+        maybeNotifySurfaceSizeChanged(textureView.getWidth(), textureView.getHeight());
+      }
     }
   }
 
@@ -973,6 +993,16 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     this.ownsSurface = ownsSurface;
   }
 
+  private void maybeNotifySurfaceSizeChanged(int width, int height) {
+    if (width != surfaceWidth || height != surfaceHeight) {
+      surfaceWidth = width;
+      surfaceHeight = height;
+      for (com.google.android.exoplayer2.video.VideoListener videoListener : videoListeners) {
+        videoListener.onSurfaceSizeChanged(width, height);
+      }
+    }
+  }
+
   private final class ComponentListener implements VideoRendererEventListener,
       AudioRendererEventListener, TextOutput, MetadataOutput, SurfaceHolder.Callback,
       TextureView.SurfaceTextureListener {
@@ -1126,12 +1156,13 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
 
     @Override
     public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
-      // Do nothing.
+      maybeNotifySurfaceSizeChanged(width, height);
     }
 
     @Override
     public void surfaceDestroyed(SurfaceHolder holder) {
       setVideoSurfaceInternal(null, false);
+      maybeNotifySurfaceSizeChanged(/* width= */ 0, /* height= */ 0);
     }
 
     // TextureView.SurfaceTextureListener implementation
@@ -1139,16 +1170,18 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     @Override
     public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height) {
       setVideoSurfaceInternal(new Surface(surfaceTexture), true);
+      maybeNotifySurfaceSizeChanged(width, height);
     }
 
     @Override
     public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int width, int height) {
-      // Do nothing.
+      maybeNotifySurfaceSizeChanged(width, height);
     }
 
     @Override
     public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
       setVideoSurfaceInternal(null, true);
+      maybeNotifySurfaceSizeChanged(/* width= */ 0, /* height= */ 0);
       return true;
     }
 
@@ -1156,7 +1189,6 @@ public class SimpleExoPlayer implements ExoPlayer, Player.VideoComponent, Player
     public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
       // Do nothing.
     }
-
   }
 
 }

library/core/src/main/java/com/google/android/exoplayer2/video/VideoListener.java

@@ -37,6 +37,19 @@ public interface VideoListener {
   void onVideoSizeChanged(
       int width, int height, int unappliedRotationDegrees, float pixelWidthHeightRatio);
 
+  /**
+   * Called each time there's a change in the size of the surface onto which the video is being
+   * rendered.
+   *
+   * @param width The surface width in pixels. May be {@link
+   *     com.google.android.exoplayer2.C#LENGTH_UNSET} if unknown, or 0 if the video is not rendered
+   *     onto a surface.
+   * @param height The surface height in pixels. May be {@link
+   *     com.google.android.exoplayer2.C#LENGTH_UNSET} if unknown, or 0 if the video is not rendered
+   *     onto a surface.
+   */
+  default void onSurfaceSizeChanged(int width, int height) {}
+
   /**
    * Called when a frame is rendered for the first time since setting the surface, and when a frame
    * is rendered for the first time since a video track was selected.