[video_player_android] Platform view support (#8466)

This PR adds support for platform views on Android as a way of displaying a video. When creating a video, it's now possible to choose between texture view approach (rendered using `Texture` widget on the Flutter side) and platform view approach (rendered on the native side, using `SurfaceView`).

`VideoPlayer` class now has nothing to do with texture. The texture-related code was moved from it to `TextureVideoPlayer` - a subclass of `VideoPlayer` that adds texture functionality. There's also `PlatformViewVideoPlayer` - a subclass of `VideoPlayer` that adds platform view functionality. In the plugin class (`create` method) we create either the platform view version or the texture version based on the parameter (`viewType`) passed in from Flutter side.

The functionality is not yet exposed in the app-facing package (only in the example app) - it will be done in a separate PR. The PR does not introduce breaking changes.

Related issues:
- [#86613](flutter/flutter#86613) - this issue requests platform view support for iOS. Here we also add it for the Android, so that it works on both mobile platforms.

Author: FirentisTFW

packages/video_player/video_player_android/CHANGELOG.md

@@ -1,5 +1,6 @@
-## NEXT
+## 2.8.0
 
+* Adds support for platform views as an optional way of displaying a video.
 * Suppresses deprecation and removal warnings for
   `TextureRegistry.SurfaceProducer.onSurfaceDestroyed`.
 

packages/video_player/video_player_android/android/src/main/java/io/flutter/plugins/videoplayer/ExoPlayerEventListener.java

@@ -4,23 +4,18 @@
 
 package io.flutter.plugins.videoplayer;
 
-import android.os.Build;
 import androidx.annotation.NonNull;
-import androidx.annotation.OptIn;
-import androidx.media3.common.Format;
 import androidx.media3.common.PlaybackException;
 import androidx.media3.common.Player;
-import androidx.media3.common.VideoSize;
 import androidx.media3.exoplayer.ExoPlayer;
-import java.util.Objects;
 
-final class ExoPlayerEventListener implements Player.Listener {
-  private final ExoPlayer exoPlayer;
-  private final VideoPlayerCallbacks events;
+public abstract class ExoPlayerEventListener implements Player.Listener {
   private boolean isBuffering = false;
   private boolean isInitialized;
+  protected final ExoPlayer exoPlayer;
+  protected final VideoPlayerCallbacks events;
 
-  private enum RotationDegrees {
+  protected enum RotationDegrees {
     ROTATE_0(0),
     ROTATE_90(90),
     ROTATE_180(180),
@@ -46,11 +41,8 @@ public int getDegrees() {
     }
   }
 
-  ExoPlayerEventListener(ExoPlayer exoPlayer, VideoPlayerCallbacks events) {
-    this(exoPlayer, events, false);
-  }
-
-  ExoPlayerEventListener(ExoPlayer exoPlayer, VideoPlayerCallbacks events, boolean initialized) {
+  public ExoPlayerEventListener(
+      @NonNull ExoPlayer exoPlayer, @NonNull VideoPlayerCallbacks events, boolean initialized) {
     this.exoPlayer = exoPlayer;
     this.events = events;
     this.isInitialized = initialized;
@@ -68,90 +60,7 @@ private void setBuffering(boolean buffering) {
     }
   }
 
-  @SuppressWarnings("SuspiciousNameCombination")
-  private void sendInitialized() {
-    if (isInitialized) {
-      return;
-    }
-    isInitialized = true;
-    VideoSize videoSize = exoPlayer.getVideoSize();
-    int rotationCorrection = 0;
-    int width = videoSize.width;
-    int height = videoSize.height;
-    if (width != 0 && height != 0) {
-      RotationDegrees reportedRotationCorrection = RotationDegrees.ROTATE_0;
-
-      if (Build.VERSION.SDK_INT <= 21) {
-        // On API 21 and below, Exoplayer may not internally handle rotation correction
-        // and reports it through VideoSize.unappliedRotationDegrees. We may apply it to
-        // fix the case of upside-down playback.
-        try {
-          reportedRotationCorrection =
-              RotationDegrees.fromDegrees(videoSize.unappliedRotationDegrees);
-          rotationCorrection =
-              getRotationCorrectionFromUnappliedRotation(reportedRotationCorrection);
-        } catch (IllegalArgumentException e) {
-          // Unapplied rotation other than 0, 90, 180, 270 reported by VideoSize. Because this is unexpected,
-          // we apply no rotation correction.
-          reportedRotationCorrection = RotationDegrees.ROTATE_0;
-          rotationCorrection = 0;
-        }
-      }
-      // TODO(camsim99): Replace this with a call to `handlesCropAndRotation` when it is
-      // available in stable. https://github.com/flutter/flutter/issues/157198
-      else if (Build.VERSION.SDK_INT < 29) {
-        // When the SurfaceTexture backend for Impeller is used, the preview should already
-        // be correctly rotated.
-        rotationCorrection = 0;
-      } else {
-        // The video's Format also provides a rotation correction that may be used to
-        // correct the rotation, so we try to use that to correct the video rotation
-        // when the ImageReader backend for Impeller is used.
-        rotationCorrection = getRotationCorrectionFromFormat(exoPlayer);
-
-        try {
-          reportedRotationCorrection = RotationDegrees.fromDegrees(rotationCorrection);
-        } catch (IllegalArgumentException e) {
-          // Rotation correction other than 0, 90, 180, 270 reported by Format. Because this is unexpected,
-          // we apply no rotation correction.
-          reportedRotationCorrection = RotationDegrees.ROTATE_0;
-          rotationCorrection = 0;
-        }
-      }
-
-      // Switch the width/height if video was taken in portrait mode and a rotation
-      // correction was detected.
-      if (reportedRotationCorrection == RotationDegrees.ROTATE_90
-          || reportedRotationCorrection == RotationDegrees.ROTATE_270) {
-        width = videoSize.height;
-        height = videoSize.width;
-      }
-    }
-    events.onInitialized(width, height, exoPlayer.getDuration(), rotationCorrection);
-  }
-
-  private int getRotationCorrectionFromUnappliedRotation(RotationDegrees unappliedRotationDegrees) {
-    int rotationCorrection = 0;
-
-    // Rotating the video with ExoPlayer does not seem to be possible with a Surface,
-    // so inform the Flutter code that the widget needs to be rotated to prevent
-    // upside-down playback for videos with unappliedRotationDegrees of 180 (other orientations
-    // work correctly without correction).
-    if (unappliedRotationDegrees == RotationDegrees.ROTATE_180) {
-      rotationCorrection = unappliedRotationDegrees.getDegrees();
-    }
-
-    return rotationCorrection;
-  }
-
-  @OptIn(markerClass = androidx.media3.common.util.UnstableApi.class)
-  // A video's Format and its rotation degrees are unstable because they are not guaranteed
-  // the same implementation across API versions. It is possible that this logic may need
-  // revisiting should the implementation change across versions of the Exoplayer API.
-  private int getRotationCorrectionFromFormat(ExoPlayer exoPlayer) {
-    Format videoFormat = Objects.requireNonNull(exoPlayer.getVideoFormat());
-    return videoFormat.rotationDegrees;
-  }
+  protected abstract void sendInitialized();
 
   @Override
   public void onPlaybackStateChanged(final int playbackState) {
@@ -161,6 +70,10 @@ public void onPlaybackStateChanged(final int playbackState) {
         events.onBufferingUpdate(exoPlayer.getBufferedPosition());
         break;
       case Player.STATE_READY:
+        if (isInitialized) {
+          return;
+        }
+        isInitialized = true;
         sendInitialized();
         break;
       case Player.STATE_ENDED:
@@ -178,7 +91,8 @@ public void onPlaybackStateChanged(final int playbackState) {
   public void onPlayerError(@NonNull final PlaybackException error) {
     setBuffering(false);
     if (error.errorCode == PlaybackException.ERROR_CODE_BEHIND_LIVE_WINDOW) {
-      // See https://exoplayer.dev/live-streaming.html#behindlivewindowexception-and-error_code_behind_live_window
+      // See
+      // https://exoplayer.dev/live-streaming.html#behindlivewindowexception-and-error_code_behind_live_window
       exoPlayer.seekToDefaultPosition();
       exoPlayer.prepare();
     } else {

packages/video_player/video_player_android/android/src/main/java/io/flutter/plugins/videoplayer/ExoPlayerState.java

@@ -4,6 +4,7 @@
 
 package io.flutter.plugins.videoplayer;
 
+import androidx.annotation.NonNull;
 import androidx.media3.common.PlaybackParameters;
 import androidx.media3.exoplayer.ExoPlayer;
 
@@ -15,7 +16,7 @@
  * is reclaimed. Upon <em>resume</em>, the player will need to be recreated, but start again at the
  * previous point (and settings).
  */
-final class ExoPlayerState {
+public final class ExoPlayerState {
   /**
    * Saves a representation of the current state of the player at the current point in time.
    *
@@ -24,12 +25,13 @@ final class ExoPlayerState {
    * @param exoPlayer the active player instance.
    * @return an opaque object representing the state.
    */
-  static ExoPlayerState save(ExoPlayer exoPlayer) {
+  @NonNull
+  public static ExoPlayerState save(@NonNull ExoPlayer exoPlayer) {
     return new ExoPlayerState(
-        /*position=*/ exoPlayer.getCurrentPosition(),
-        /*repeatMode=*/ exoPlayer.getRepeatMode(),
-        /*volume=*/ exoPlayer.getVolume(),
-        /*playbackParameters=*/ exoPlayer.getPlaybackParameters());
+        /* position= */ exoPlayer.getCurrentPosition(),
+        /* repeatMode= */ exoPlayer.getRepeatMode(),
+        /* volume= */ exoPlayer.getVolume(),
+        /* playbackParameters= */ exoPlayer.getPlaybackParameters());
   }
 
   private ExoPlayerState(
@@ -60,7 +62,7 @@ private ExoPlayerState(
    *
    * @param exoPlayer the new player instance to reflect the state back to.
    */
-  void restore(ExoPlayer exoPlayer) {
+  public void restore(@NonNull ExoPlayer exoPlayer) {
     exoPlayer.seekTo(position);
     exoPlayer.setRepeatMode(repeatMode);
     exoPlayer.setVolume(volume);

packages/video_player/video_player_android/android/src/main/java/io/flutter/plugins/videoplayer/HttpVideoAsset.java

@@ -37,7 +37,7 @@ final class HttpVideoAsset extends VideoAsset {
 
   @NonNull
   @Override
-  MediaItem getMediaItem() {
+  public MediaItem getMediaItem() {
     MediaItem.Builder builder = new MediaItem.Builder().setUri(assetUrl);
     String mimeType = null;
     switch (streamingFormat) {
@@ -57,8 +57,9 @@ MediaItem getMediaItem() {
     return builder.build();
   }
 
+  @NonNull
   @Override
-  MediaSource.Factory getMediaSourceFactory(Context context) {
+  public MediaSource.Factory getMediaSourceFactory(@NonNull Context context) {
     return getMediaSourceFactory(context, new DefaultHttpDataSource.Factory());
   }
 

packages/video_player/video_player_android/android/src/main/java/io/flutter/plugins/videoplayer/LocalVideoAsset.java

@@ -17,12 +17,13 @@ final class LocalVideoAsset extends VideoAsset {
 
   @NonNull
   @Override
-  MediaItem getMediaItem() {
+  public MediaItem getMediaItem() {
     return new MediaItem.Builder().setUri(assetUrl).build();
   }
 
+  @NonNull
   @Override
-  MediaSource.Factory getMediaSourceFactory(Context context) {
+  public MediaSource.Factory getMediaSourceFactory(@NonNull Context context) {
     return new DefaultMediaSourceFactory(context);
   }
 }