Clean up AdTagLoader and ImaAdsLoader

In preparation for adding support for ads in playlists:
- Make releasing a no-op if the instance was already released
- Remove null checks on non-null `adDisplayContainer` and `adsLoader`
- Move initializing the ads manager into a private method as it will need to be
  called from two places soon.
- Misc other cleanup.

Issue: #3750
PiperOrigin-RevId: 341021493

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/AdTagLoader.java

@@ -152,6 +152,8 @@ import java.util.Map;
   private long contentDurationMs;
   private AdPlaybackState adPlaybackState;
 
+  private boolean released;
+
   // Fields tracking IMA's state.
 
   /** Whether IMA has sent an ad event to pause content since the last resume content event. */
@@ -300,14 +302,12 @@ import java.util.Map;
               adsId, ImaUtil.getAdGroupTimesUsForCuePoints(adsManager.getAdCuePoints()));
       updateAdPlaybackState();
     }
-    if (adDisplayContainer != null) {
-      for (OverlayInfo overlayInfo : adViewProvider.getAdOverlayInfos()) {
-        adDisplayContainer.registerFriendlyObstruction(
-            imaFactory.createFriendlyObstruction(
-                overlayInfo.view,
-                ImaUtil.getFriendlyObstructionPurpose(overlayInfo.purpose),
-                overlayInfo.reasonDetail));
-      }
+    for (OverlayInfo overlayInfo : adViewProvider.getAdOverlayInfos()) {
+      adDisplayContainer.registerFriendlyObstruction(
+          imaFactory.createFriendlyObstruction(
+              overlayInfo.view,
+              ImaUtil.getFriendlyObstructionPurpose(overlayInfo.purpose),
+              overlayInfo.reasonDetail));
     }
   }
 
@@ -326,9 +326,7 @@ import java.util.Map;
     lastVolumePercent = getPlayerVolumePercent();
     lastAdProgress = getAdVideoProgressUpdate();
     lastContentProgress = getContentVideoProgressUpdate();
-    if (adDisplayContainer != null) {
-      adDisplayContainer.unregisterAllFriendlyObstructions();
-    }
+    adDisplayContainer.unregisterAllFriendlyObstructions();
     player.removeListener(this);
     this.player = null;
     eventListener = null;
@@ -336,16 +334,18 @@ import java.util.Map;
 
   /** Releases all resources used by the ad tag loader. */
   public void release() {
+    if (released) {
+      return;
+    }
+    released = true;
     pendingAdRequestContext = null;
     destroyAdsManager();
-    if (adsLoader != null) {
-      adsLoader.removeAdsLoadedListener(componentListener);
-      adsLoader.removeAdErrorListener(componentListener);
-      if (configuration.applicationAdErrorListener != null) {
-        adsLoader.removeAdErrorListener(configuration.applicationAdErrorListener);
-      }
-      adsLoader.release();
+    adsLoader.removeAdsLoadedListener(componentListener);
+    adsLoader.removeAdErrorListener(componentListener);
+    if (configuration.applicationAdErrorListener != null) {
+      adsLoader.removeAdErrorListener(configuration.applicationAdErrorListener);
     }
+    adsLoader.release();
     imaPausedContent = false;
     imaAdState = IMA_AD_STATE_NONE;
     imaAdMediaInfo = null;
@@ -394,27 +394,15 @@ import java.util.Map;
     }
     checkArgument(timeline.getPeriodCount() == 1);
     this.timeline = timeline;
-    long contentDurationUs = timeline.getPeriod(/* periodIndex= */ 0, period).durationUs;
+    Player player = checkNotNull(this.player);
+    long contentDurationUs = timeline.getPeriod(player.getCurrentPeriodIndex(), period).durationUs;
     contentDurationMs = C.usToMs(contentDurationUs);
-    if (contentDurationUs != C.TIME_UNSET) {
+    if (contentDurationUs != adPlaybackState.contentDurationUs) {
       adPlaybackState = adPlaybackState.withContentDurationUs(contentDurationUs);
-    }
-    @Nullable AdsManager adsManager = this.adsManager;
-    if (!isAdsManagerInitialized && adsManager != null) {
-      isAdsManagerInitialized = true;
-      @Nullable AdsRenderingSettings adsRenderingSettings = setupAdsRendering();
-      if (adsRenderingSettings == null) {
-        // There are no ads to play.
-        destroyAdsManager();
-      } else {
-        adsManager.init(adsRenderingSettings);
-        adsManager.start();
-        if (configuration.debugModeEnabled) {
-          Log.d(TAG, "Initialized with ads rendering settings: " + adsRenderingSettings);
-        }
-      }
       updateAdPlaybackState();
     }
+    long contentPositionMs = getContentPeriodPositionMs(player, timeline, period);
+    maybeInitializeAdsManager(contentPositionMs, contentDurationMs);
     handleTimelineOrPositionChanged();
   }
 
@@ -515,12 +503,33 @@ import java.util.Map;
     return adsLoader;
   }
 
+  private void maybeInitializeAdsManager(long contentPositionMs, long contentDurationMs) {
+    @Nullable AdsManager adsManager = this.adsManager;
+    if (!isAdsManagerInitialized && adsManager != null) {
+      isAdsManagerInitialized = true;
+      @Nullable
+      AdsRenderingSettings adsRenderingSettings =
+          setupAdsRendering(contentPositionMs, contentDurationMs);
+      if (adsRenderingSettings == null) {
+        // There are no ads to play.
+        destroyAdsManager();
+      } else {
+        adsManager.init(adsRenderingSettings);
+        adsManager.start();
+        if (configuration.debugModeEnabled) {
+          Log.d(TAG, "Initialized with ads rendering settings: " + adsRenderingSettings);
+        }
+      }
+      updateAdPlaybackState();
+    }
+  }
+
   /**
    * Configures ads rendering for starting playback, returning the settings for the IMA SDK or
    * {@code null} if no ads should play.
    */
   @Nullable
-  private AdsRenderingSettings setupAdsRendering() {
+  private AdsRenderingSettings setupAdsRendering(long contentPositionMs, long contentDurationMs) {
     AdsRenderingSettings adsRenderingSettings = imaFactory.createAdsRenderingSettings();
     adsRenderingSettings.setEnablePreloading(true);
     adsRenderingSettings.setMimeTypes(
@@ -541,7 +550,6 @@ import java.util.Map;
 
     // Skip ads based on the start position as required.
     long[] adGroupTimesUs = adPlaybackState.adGroupTimesUs;
-    long contentPositionMs = getContentPeriodPositionMs(checkNotNull(player), timeline, period);
     int adGroupForPositionIndex =
         adPlaybackState.getAdGroupIndexForPositionUs(
             C.msToUs(contentPositionMs), C.msToUs(contentDurationMs));
@@ -957,7 +965,6 @@ import java.util.Map;
       }
       return;
     }
-    checkNotNull(player);
     imaAdState = IMA_AD_STATE_NONE;
     stopUpdatingAdProgress();
     // TODO: Handle the skipped event so the ad can be marked as skipped rather than played.
@@ -1155,10 +1162,12 @@ import java.util.Map;
   private static long getContentPeriodPositionMs(
       Player player, Timeline timeline, Timeline.Period period) {
     long contentWindowPositionMs = player.getContentPosition();
-    return contentWindowPositionMs
-        - (timeline.isEmpty()
-            ? 0
-            : timeline.getPeriod(/* periodIndex= */ 0, period).getPositionInWindowMs());
+    if (timeline.isEmpty()) {
+      return contentWindowPositionMs;
+    } else {
+      return contentWindowPositionMs
+          - timeline.getPeriod(player.getCurrentPeriodIndex(), period).getPositionInWindowMs();
+    }
   }
 
   private static boolean hasMidrollAdGroups(long[] adGroupTimesUs) {

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java

@@ -31,7 +31,6 @@ import androidx.annotation.VisibleForTesting;
 import com.google.ads.interactivemedia.v3.api.AdDisplayContainer;
 import com.google.ads.interactivemedia.v3.api.AdErrorEvent.AdErrorListener;
 import com.google.ads.interactivemedia.v3.api.AdEvent.AdEventListener;
-import com.google.ads.interactivemedia.v3.api.AdsLoader;
 import com.google.ads.interactivemedia.v3.api.AdsManager;
 import com.google.ads.interactivemedia.v3.api.AdsRenderingSettings;
 import com.google.ads.interactivemedia.v3.api.AdsRequest;
@@ -46,6 +45,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.source.MediaSourceFactory;
+import com.google.android.exoplayer2.source.ads.AdsLoader;
 import com.google.android.exoplayer2.source.ads.AdsMediaSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.util.MimeTypes;
@@ -61,8 +61,7 @@ import java.util.List;
 import java.util.Set;
 
 /**
- * {@link com.google.android.exoplayer2.source.ads.AdsLoader} using the IMA SDK. All methods must be
- * called on the main thread.
+ * {@link AdsLoader} using the IMA SDK. All methods must be called on the main thread.
  *
  * <p>The player instance that will play the loaded ads must be set before playback using {@link
  * #setPlayer(Player)}. If the ads loader is no longer required, it must be released by calling
@@ -83,8 +82,7 @@ import java.util.Set;
  * href="https://developers.google.com/interactive-media-ads/docs/sdks/android/client-side/omsdk">IMA
  * SDK Open Measurement documentation</a> for more information.
  */
-public final class ImaAdsLoader
-    implements Player.EventListener, com.google.android.exoplayer2.source.ads.AdsLoader {
+public final class ImaAdsLoader implements Player.EventListener, AdsLoader {
 
   static {
     ExoPlayerLibraryInfo.registerModule("goog.exo.ima");
@@ -154,8 +152,8 @@ public final class ImaAdsLoader
 
     /**
      * Sets a listener for ad errors that will be passed to {@link
-     * AdsLoader#addAdErrorListener(AdErrorListener)} and {@link
-     * AdsManager#addAdErrorListener(AdErrorListener)}.
+     * com.google.ads.interactivemedia.v3.api.AdsLoader#addAdErrorListener(AdErrorListener)} and
+     * {@link AdsManager#addAdErrorListener(AdErrorListener)}.
      *
      * @param adErrorListener The ad error listener.
      * @return This builder, for convenience.
@@ -384,11 +382,11 @@ public final class ImaAdsLoader
   }
 
   /**
-   * Returns the underlying {@link AdsLoader} wrapped by this instance, or {@code null} if ads have
-   * not been requested yet.
+   * Returns the underlying {@link com.google.ads.interactivemedia.v3.api.AdsLoader} wrapped by this
+   * instance, or {@code null} if ads have not been requested yet.
    */
   @Nullable
-  public AdsLoader getAdsLoader() {
+  public com.google.ads.interactivemedia.v3.api.AdsLoader getAdsLoader() {
     return adTagLoader != null ? adTagLoader.getAdsLoader() : null;
   }
 
@@ -400,8 +398,8 @@ public final class ImaAdsLoader
    * AdDisplayContainer#registerFriendlyObstruction(FriendlyObstruction)} will be unregistered
    * automatically when the media source detaches from this instance. It is therefore necessary to
    * re-register views each time the ads loader is reused. Alternatively, provide overlay views via
-   * the {@link com.google.android.exoplayer2.source.ads.AdsLoader.AdViewProvider} when creating the
-   * media source to benefit from automatic registration.
+   * the {@link AdViewProvider} when creating the media source to benefit from automatic
+   * registration.
    */
   @Nullable
   public AdDisplayContainer getAdDisplayContainer() {
@@ -448,7 +446,7 @@ public final class ImaAdsLoader
     }
   }
 
-  // com.google.android.exoplayer2.source.ads.AdsLoader implementation.
+  // AdsLoader implementation.
 
   @Override
   public void setPlayer(@Nullable Player player) {
@@ -576,7 +574,7 @@ public final class ImaAdsLoader
     }
 
     @Override
-    public AdsLoader createAdsLoader(
+    public com.google.ads.interactivemedia.v3.api.AdsLoader createAdsLoader(
         Context context, ImaSdkSettings imaSdkSettings, AdDisplayContainer adDisplayContainer) {
       return ImaSdkFactory.getInstance()
           .createAdsLoader(context, imaSdkSettings, adDisplayContainer);