Convert DownloadManager.Listener methods no-op default methods

PiperOrigin-RevId: 239019504

demos/main/src/main/java/com/google/android/exoplayer2/demo/DownloadTracker.java

@@ -35,7 +35,6 @@ import com.google.android.exoplayer2.offline.DownloadService;
 import com.google.android.exoplayer2.offline.DownloadState;
 import com.google.android.exoplayer2.offline.DownloadStateCursor;
 import com.google.android.exoplayer2.offline.StreamKey;
-import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.trackselection.MappingTrackSelector.MappedTrackInfo;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.util.Log;
@@ -130,11 +129,6 @@ public class DownloadTracker implements DownloadManager.Listener {
   // DownloadManager.Listener
 
   @Override
-  public void onInitialized(DownloadManager downloadManager) {
-    // Do nothing.
-  }
-
-  @Override
   public void onDownloadStateChanged(DownloadManager downloadManager, DownloadState downloadState) {
     if (downloadState.state == DownloadState.STATE_REMOVED
         || downloadState.state == DownloadState.STATE_FAILED) {
@@ -145,19 +139,6 @@ public class DownloadTracker implements DownloadManager.Listener {
     }
   }
 
-  @Override
-  public void onIdle(DownloadManager downloadManager) {
-    // Do nothing.
-  }
-
-  @Override
-  public void onRequirementsStateChanged(
-      DownloadManager downloadManager,
-      Requirements requirements,
-      @Requirements.RequirementFlags int notMetRequirements) {
-    // Do nothing.
-  }
-
   // Internal methods
 
   private void loadTrackedActions() {

library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadManager.java

@@ -68,21 +68,23 @@ public final class DownloadManager {
      *
      * @param downloadManager The reporting instance.
      */
-    void onInitialized(DownloadManager downloadManager);
+    default void onInitialized(DownloadManager downloadManager) {}
+
     /**
      * Called when the state of a download changes.
      *
      * @param downloadManager The reporting instance.
      * @param downloadState The state of the download.
      */
-    void onDownloadStateChanged(DownloadManager downloadManager, DownloadState downloadState);
+    default void onDownloadStateChanged(
+        DownloadManager downloadManager, DownloadState downloadState) {}
 
     /**
      * Called when there is no active download left.
      *
      * @param downloadManager The reporting instance.
      */
-    void onIdle(DownloadManager downloadManager);
+    default void onIdle(DownloadManager downloadManager) {}
 
     /**
      * Called when the download requirements state changed.
@@ -92,10 +94,10 @@ public final class DownloadManager {
      * @param notMetRequirements {@link Requirements.RequirementFlags RequirementFlags} that are not
      *     met, or 0.
      */
-    void onRequirementsStateChanged(
+    default void onRequirementsStateChanged(
         DownloadManager downloadManager,
         Requirements requirements,
-        @Requirements.RequirementFlags int notMetRequirements);
+        @Requirements.RequirementFlags int notMetRequirements) {}
   }
 
   /** The default maximum number of simultaneous downloads. */

library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadService.java

@@ -533,11 +533,6 @@ public abstract class DownloadService extends Service {
     }
 
     @Override
-    public void onInitialized(DownloadManager downloadManager) {
-      // Do nothing.
-    }
-
-    @Override
     public void onDownloadStateChanged(
         DownloadManager downloadManager, DownloadState downloadState) {
       if (downloadService != null) {

testutils_robolectric/src/main/java/com/google/android/exoplayer2/testutil/TestDownloadManagerListener.java

@@ -20,7 +20,6 @@ import static com.google.common.truth.Truth.assertThat;
 import android.os.ConditionVariable;
 import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadState;
-import com.google.android.exoplayer2.scheduler.Requirements;
 import java.util.HashMap;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.CountDownLatch;
@@ -83,12 +82,6 @@ public final class TestDownloadManagerListener implements DownloadManager.Listen
     }
   }
 
-  @Override
-  public void onRequirementsStateChanged(
-      DownloadManager downloadManager, Requirements requirements, int notMetRequirements) {
-    // Do nothing.
-  }
-
   /**
    * Blocks until all remove and download tasks are complete and throws an exception if there was an
    * error.