[video_player] Move most Android event logic to Dart

packages/video_player/video_player_android/CHANGELOG.md

@@ -1,3 +1,10 @@
+## 2.8.15
+
+* Moves video event processing logic to Dart, and fixes an issue where buffer
+  range would not be updated for a paused video.
+* Switches to Kotlin for Pigeon-generated code.
+* Adopts type-safe event channels for internal communication.
+
 ## 2.8.14
 
 * Restructures internal logic for player creation and tracking.

packages/video_player/video_player_android/android/build.gradle

@@ -2,13 +2,15 @@ group 'io.flutter.plugins.videoplayer'
 version '1.0-SNAPSHOT'
 
 buildscript {
+    ext.kotlin_version = '2.2.10'
     repositories {
         google()
         mavenCentral()
     }
 
     dependencies {
         classpath 'com.android.tools.build:gradle:8.12.1'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
@@ -20,6 +22,7 @@ rootProject.allprojects {
 }
 
 apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
 
 android {
     namespace = "io.flutter.plugins.videoplayer"
@@ -38,6 +41,13 @@ android {
         sourceCompatibility = JavaVersion.VERSION_11
         targetCompatibility = JavaVersion.VERSION_11
     }
+    kotlinOptions {
+        jvmTarget = '11'
+    }
+
+    sourceSets {
+        main.java.srcDirs += 'src/main/kotlin'
+    }
 
     dependencies {
         def exoplayer_version = "1.5.1"

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

@@ -10,7 +10,6 @@
 import androidx.media3.exoplayer.ExoPlayer;
 
 public abstract class ExoPlayerEventListener implements Player.Listener {
-  private boolean isBuffering = false;
   private boolean isInitialized = false;
   protected final ExoPlayer exoPlayer;
   protected final VideoPlayerCallbacks events;
@@ -47,47 +46,34 @@ public ExoPlayerEventListener(
     this.events = events;
   }
 
-  private void setBuffering(boolean buffering) {
-    if (isBuffering == buffering) {
-      return;
-    }
-    isBuffering = buffering;
-    if (buffering) {
-      events.onBufferingStart();
-    } else {
-      events.onBufferingEnd();
-    }
-  }
-
   protected abstract void sendInitialized();
 
   @Override
   public void onPlaybackStateChanged(final int playbackState) {
+    PlatformPlaybackState platformState = PlatformPlaybackState.UNKNOWN;
     switch (playbackState) {
       case Player.STATE_BUFFERING:
-        setBuffering(true);
-        events.onBufferingUpdate(exoPlayer.getBufferedPosition());
+        platformState = PlatformPlaybackState.BUFFERING;
         break;
       case Player.STATE_READY:
+        platformState = PlatformPlaybackState.READY;
         if (!isInitialized) {
           isInitialized = true;
           sendInitialized();
         }
         break;
       case Player.STATE_ENDED:
-        events.onCompleted();
+        platformState = PlatformPlaybackState.ENDED;
         break;
       case Player.STATE_IDLE:
+        platformState = PlatformPlaybackState.IDLE;
         break;
     }
-    if (playbackState != Player.STATE_BUFFERING) {
-      setBuffering(false);
-    }
+    events.onPlaybackStateChanged(platformState);
   }
 
   @Override
   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