Clean up offline notifications

- It's much cleaner to split completed/error notification methods.
- Make error notification show the content title in the demo app.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=194920507

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

@@ -16,7 +16,6 @@
 package com.google.android.exoplayer2.demo;
 
 import android.app.Notification;
-import android.util.Pair;
 import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadManager.TaskState;
 import com.google.android.exoplayer2.offline.DownloadService;
@@ -27,7 +26,6 @@ import com.google.android.exoplayer2.source.dash.offline.DashDownloadAction;
 import com.google.android.exoplayer2.source.hls.offline.HlsDownloadAction;
 import com.google.android.exoplayer2.source.smoothstreaming.offline.SsDownloadAction;
 import com.google.android.exoplayer2.ui.DownloadNotificationUtil;
-import com.google.android.exoplayer2.util.ErrorMessageProvider;
 import com.google.android.exoplayer2.util.NotificationUtil;
 import com.google.android.exoplayer2.util.Util;
 
@@ -76,32 +74,39 @@ public class DemoDownloadService extends DownloadService {
 
   @Override
   protected Notification getForegroundNotification(TaskState[] taskStates) {
-    return DownloadNotificationUtil.createProgressNotification(
-        taskStates,
+    return DownloadNotificationUtil.buildProgressNotification(
         /* context= */ this,
         R.drawable.exo_controls_play,
         CHANNEL_ID,
         /* contentIntent= */ null,
-        /* message= */ null);
+        /* message= */ null,
+        taskStates);
   }
 
   @Override
   protected void onTaskStateChanged(TaskState taskState) {
+    if (taskState.action.isRemoveAction) {
+      return;
+    }
+    Notification notification = null;
+    if (taskState.state == TaskState.STATE_COMPLETED) {
+      notification =
+          DownloadNotificationUtil.buildDownloadCompletedNotification(
+              /* context= */ this,
+              R.drawable.exo_controls_play,
+              CHANNEL_ID,
+              /* contentIntent= */ null,
+              taskState.action.data);
+    } else if (taskState.state == TaskState.STATE_FAILED) {
+      notification =
+          DownloadNotificationUtil.buildDownloadFailedNotification(
+              /* context= */ this,
+              R.drawable.exo_controls_play,
+              CHANNEL_ID,
+              /* contentIntent= */ null,
+              taskState.action.data);
+    }
     int notificationId = FOREGROUND_NOTIFICATION_ID + 1 + taskState.taskId;
-    Notification downloadNotification =
-        DownloadNotificationUtil.createDownloadFinishedNotification(
-            taskState,
-            /* context= */ this,
-            R.drawable.exo_controls_play,
-            CHANNEL_ID,
-            /* contentIntent= */ null,
-            taskState.action.data,
-            new ErrorMessageProvider<Throwable>() {
-              @Override
-              public Pair<Integer, String> getErrorMessage(Throwable throwable) {
-                return new Pair<>(0, throwable.getLocalizedMessage());
-              }
-            });
-    NotificationUtil.setNotification(/* context= */ this, notificationId, downloadNotification);
+    NotificationUtil.setNotification(this, notificationId, notification);
   }
 }

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

@@ -16,8 +16,8 @@
 package com.google.android.exoplayer2.offline;
 
 import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_CANCELED;
-import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_ENDED;
-import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_ERROR;
+import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_COMPLETED;
+import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_FAILED;
 import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_QUEUED;
 import static com.google.android.exoplayer2.offline.DownloadManager.TaskState.STATE_STARTED;
 
@@ -487,23 +487,23 @@ public final class DownloadManager {
      *
      * <pre>
      *                    -&gt; canceled
-     * queued &lt;-&gt; started -&gt; ended
-     *                    -&gt; error
+     * queued &lt;-&gt; started -&gt; completed
+     *                    -&gt; failed
      * </pre>
      */
     @Retention(RetentionPolicy.SOURCE)
-    @IntDef({STATE_QUEUED, STATE_STARTED, STATE_ENDED, STATE_CANCELED, STATE_ERROR})
+    @IntDef({STATE_QUEUED, STATE_STARTED, STATE_COMPLETED, STATE_CANCELED, STATE_FAILED})
     public @interface State {}
     /** The task is waiting to be started. */
     public static final int STATE_QUEUED = 0;
     /** The task is currently started. */
     public static final int STATE_STARTED = 1;
     /** The task completed. */
-    public static final int STATE_ENDED = 2;
+    public static final int STATE_COMPLETED = 2;
     /** The task was canceled. */
     public static final int STATE_CANCELED = 3;
     /** The task failed. */
-    public static final int STATE_ERROR = 4;
+    public static final int STATE_FAILED = 4;
 
     /** Returns the state string for the given state value. */
     public static String getStateString(@State int state) {
@@ -512,12 +512,12 @@ public final class DownloadManager {
           return "QUEUED";
         case STATE_STARTED:
           return "STARTED";
-        case STATE_ENDED:
-          return "ENDED";
+        case STATE_COMPLETED:
+          return "COMPLETED";
         case STATE_CANCELED:
           return "CANCELED";
-        case STATE_ERROR:
-          return "ERROR";
+        case STATE_FAILED:
+          return "FAILED";
         default:
           throw new IllegalStateException();
       }
@@ -538,7 +538,7 @@ public final class DownloadManager {
     /** The total number of downloaded bytes. */
     public final long downloadedBytes;
 
-    /** If {@link #state} is {@link #STATE_ERROR} then this is the cause, otherwise null. */
+    /** If {@link #state} is {@link #STATE_FAILED} then this is the cause, otherwise null. */
     public final Throwable error;
 
     private TaskState(
@@ -566,24 +566,24 @@ public final class DownloadManager {
      * <p>Transition map (vertical states are source states):
      *
      * <pre>
-     *             +------+-------+-----+-----------+-----------+--------+--------+-----+
-     *             |queued|started|ended|q_canceling|s_canceling|canceled|stopping|error|
-     * +-----------+------+-------+-----+-----------+-----------+--------+--------+-----+
-     * |queued     |      |   X   |     |     X     |           |        |        |     |
-     * |started    |      |       |  X  |           |     X     |        |   X    |  X  |
-     * |q_canceling|      |       |     |           |           |   X    |        |     |
-     * |s_canceling|      |       |     |           |           |   X    |        |     |
-     * |stopping   |   X  |       |     |           |           |        |        |     |
-     * +-----------+------+-------+-----+-----------+-----------+--------+--------+-----+
+     *             +------+-------+---------+-----------+-----------+--------+--------+------+
+     *             |queued|started|completed|q_canceling|s_canceling|canceled|stopping|failed|
+     * +-----------+------+-------+---------+-----------+-----------+--------+--------+------+
+     * |queued     |      |   X   |         |     X     |           |        |        |      |
+     * |started    |      |       |    X    |           |     X     |        |   X    |   X  |
+     * |q_canceling|      |       |         |           |           |   X    |        |      |
+     * |s_canceling|      |       |         |           |           |   X    |        |      |
+     * |stopping   |   X  |       |         |           |           |        |        |      |
+     * +-----------+------+-------+---------+-----------+-----------+--------+--------+------+
      * </pre>
      */
     @Retention(RetentionPolicy.SOURCE)
     @IntDef({
       STATE_QUEUED,
       STATE_STARTED,
-      STATE_ENDED,
+      STATE_COMPLETED,
       STATE_CANCELED,
-      STATE_ERROR,
+      STATE_FAILED,
       STATE_QUEUED_CANCELING,
       STATE_STARTED_CANCELING,
       STATE_STARTED_STOPPING
@@ -622,8 +622,8 @@ public final class DownloadManager {
 
     /** Returns whether the task is finished. */
     public boolean isFinished() {
-      return currentState == STATE_ERROR
-          || currentState == STATE_ENDED
+      return currentState == STATE_FAILED
+          || currentState == STATE_COMPLETED
           || currentState == STATE_CANCELED;
     }
 
@@ -778,7 +778,9 @@ public final class DownloadManager {
             @Override
             public void run() {
               if (changeStateAndNotify(
-                      STATE_STARTED, finalError != null ? STATE_ERROR : STATE_ENDED, finalError)
+                      STATE_STARTED,
+                      finalError != null ? STATE_FAILED : STATE_COMPLETED,
+                      finalError)
                   || changeStateAndNotify(STATE_STARTED_CANCELING, STATE_CANCELED)
                   || changeStateAndNotify(STATE_STARTED_STOPPING, STATE_QUEUED)) {
                 return;

library/core/src/test/java/com/google/android/exoplayer2/offline/DownloadManagerTest.java

@@ -102,21 +102,21 @@ public class DownloadManagerTest {
     for (int i = 0; i <= MIN_RETRY_COUNT; i++) {
       fakeDownloader.assertStarted(MAX_RETRY_DELAY).unblock();
     }
-    downloadAction.assertError();
+    downloadAction.assertFailed();
     testDownloadListener.clearDownloadError();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
 
   @Test
-  public void testDownloadNoRetryWhenCancelled() throws Throwable {
+  public void testDownloadNoRetryWhenCanceled() throws Throwable {
     FakeDownloadAction downloadAction = createDownloadAction("media 1").ignoreInterrupts();
     downloadAction.getFakeDownloader().enableDownloadIOException = true;
     downloadAction.post().assertStarted();
 
     FakeDownloadAction removeAction = createRemoveAction("media 1").post();
 
-    downloadAction.unblock().assertCancelled();
+    downloadAction.unblock().assertCanceled();
     removeAction.unblock();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
@@ -135,7 +135,7 @@ public class DownloadManagerTest {
       }
       fakeDownloader.unblock();
     }
-    downloadAction.assertEnded();
+    downloadAction.assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -156,7 +156,7 @@ public class DownloadManagerTest {
       }
       fakeDownloader.unblock();
     }
-    downloadAction.assertEnded();
+    downloadAction.assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -207,13 +207,13 @@ public class DownloadManagerTest {
     removeAction1.post().assertDoesNotStart();
 
     // downloadAction2 finishes but it isn't enough to start removeAction1.
-    downloadAction2.unblock().assertCancelled();
+    downloadAction2.unblock().assertCanceled();
     removeAction1.assertDoesNotStart();
     // downloadAction3 is post to DownloadManager but it waits for removeAction1 to finish.
     downloadAction3.post().assertDoesNotStart();
 
     // When downloadAction1 finishes, removeAction1 starts.
-    downloadAction1.unblock().assertCancelled();
+    downloadAction1.unblock().assertCanceled();
     removeAction1.assertStarted();
     // downloadAction3 still waits removeAction1
     downloadAction3.assertDoesNotStart();
@@ -221,9 +221,9 @@ public class DownloadManagerTest {
     // removeAction2 is posted. removeAction1 and downloadAction3 is canceled so removeAction2
     // starts immediately.
     removeAction2.post();
-    removeAction1.assertCancelled();
-    downloadAction3.assertCancelled();
-    removeAction2.assertStarted().unblock().assertEnded();
+    removeAction1.assertCanceled();
+    downloadAction3.assertCanceled();
+    removeAction2.assertStarted().unblock().assertCompleted();
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
 
@@ -237,10 +237,10 @@ public class DownloadManagerTest {
     removeAction2.post().assertDoesNotStart();
     removeAction3.post().assertDoesNotStart();
 
-    removeAction2.assertCancelled();
+    removeAction2.assertCanceled();
 
-    removeAction1.unblock().assertCancelled();
-    removeAction3.assertStarted().unblock().assertEnded();
+    removeAction1.unblock().assertCanceled();
+    removeAction3.assertStarted().unblock().assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -272,11 +272,11 @@ public class DownloadManagerTest {
     downloadAction1.post().assertDoesNotStart();
     downloadAction2.post().assertDoesNotStart();
 
-    removeAction.unblock().assertEnded();
+    removeAction.unblock().assertCompleted();
     downloadAction1.assertStarted();
     downloadAction2.assertStarted();
-    downloadAction1.unblock().assertEnded();
-    downloadAction2.unblock().assertEnded();
+    downloadAction1.unblock().assertCompleted();
+    downloadAction2.unblock().assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -291,11 +291,11 @@ public class DownloadManagerTest {
     downloadAction1.post().assertDoesNotStart();
     downloadAction2.post().assertDoesNotStart();
 
-    removeAction.unblock().assertEnded();
+    removeAction.unblock().assertCompleted();
     downloadAction1.assertStarted();
     downloadAction2.assertStarted();
-    downloadAction1.unblock().assertEnded();
-    downloadAction2.unblock().assertEnded();
+    downloadAction1.unblock().assertCompleted();
+    downloadAction2.unblock().assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -310,11 +310,11 @@ public class DownloadManagerTest {
     removeAction1.post().assertDoesNotStart();
     removeAction2.post().assertStarted();
 
-    downloadAction.unblock().assertCancelled();
-    removeAction2.unblock().assertEnded();
+    downloadAction.unblock().assertCanceled();
+    removeAction2.unblock().assertCompleted();
 
     removeAction1.assertStarted();
-    removeAction1.unblock().assertEnded();
+    removeAction1.unblock().assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -342,14 +342,14 @@ public class DownloadManagerTest {
     download1Action.assertStopped();
 
     // remove actions aren't stopped.
-    remove2Action.unblock().assertEnded();
+    remove2Action.unblock().assertCompleted();
     // Although remove2Action is finished, download2Action doesn't start.
     download2Action.assertDoesNotStart();
 
     // When a new remove action is added, it cancels stopped download actions with the same media.
     remove1Action.post();
-    download1Action.assertCancelled();
-    remove1Action.assertStarted().unblock().assertEnded();
+    download1Action.assertCanceled();
+    remove1Action.assertStarted().unblock().assertCompleted();
 
     // New download actions can be added but they don't start.
     download3Action.post().assertDoesNotStart();
@@ -362,8 +362,8 @@ public class DownloadManagerTest {
           }
         });
 
-    download2Action.assertStarted().unblock().assertEnded();
-    download3Action.assertStarted().unblock().assertEnded();
+    download2Action.assertStarted().unblock().assertCompleted();
+    download3Action.assertStarted().unblock().assertCompleted();
 
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
@@ -456,7 +456,7 @@ public class DownloadManagerTest {
   }
 
   private void doTestActionRuns(FakeDownloadAction action) throws Throwable {
-    action.post().assertStarted().unblock().assertEnded();
+    action.post().assertStarted().unblock().assertCompleted();
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
 
@@ -468,7 +468,7 @@ public class DownloadManagerTest {
     action1.unblock();
     action2.assertStarted();
 
-    action2.unblock().assertEnded();
+    action2.unblock().assertCompleted();
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
 
@@ -476,8 +476,8 @@ public class DownloadManagerTest {
       throws Throwable {
     action1.post().assertStarted();
     action2.post().assertStarted();
-    action1.unblock().assertEnded();
-    action2.unblock().assertEnded();
+    action1.unblock().assertCompleted();
+    action2.unblock().assertCompleted();
     testDownloadListener.blockUntilTasksCompleteAndThrowAnyDownloadError();
   }
 
@@ -504,7 +504,7 @@ public class DownloadManagerTest {
 
     @Override
     public void onTaskStateChanged(DownloadManager downloadManager, TaskState taskState) {
-      if (taskState.state == TaskState.STATE_ERROR && downloadError == null) {
+      if (taskState.state == TaskState.STATE_FAILED && downloadError == null) {
         downloadError = taskState.error;
       }
       ((FakeDownloadAction) taskState.action).onStateChange(taskState.state);
@@ -583,15 +583,15 @@ public class DownloadManagerTest {
       return assertState(TaskState.STATE_STARTED);
     }
 
-    private FakeDownloadAction assertEnded() {
-      return assertState(TaskState.STATE_ENDED);
+    private FakeDownloadAction assertCompleted() {
+      return assertState(TaskState.STATE_COMPLETED);
     }
 
-    private FakeDownloadAction assertError() {
-      return assertState(TaskState.STATE_ERROR);
+    private FakeDownloadAction assertFailed() {
+      return assertState(TaskState.STATE_FAILED);
     }
 
-    private FakeDownloadAction assertCancelled() {
+    private FakeDownloadAction assertCanceled() {
       return assertState(TaskState.STATE_CANCELED);
     }
 

library/dash/src/test/java/com/google/android/exoplayer2/source/dash/offline/TestDownloadListener.java

@@ -41,7 +41,7 @@ import java.util.concurrent.TimeUnit;
   @Override
   public void onTaskStateChanged(
       DownloadManager downloadManager, DownloadManager.TaskState taskState) {
-    if (taskState.state == DownloadManager.TaskState.STATE_ERROR && downloadError == null) {
+    if (taskState.state == DownloadManager.TaskState.STATE_FAILED && downloadError == null) {
       downloadError = taskState.error;
     }
   }

library/ui/src/main/java/com/google/android/exoplayer2/ui/DownloadNotificationUtil.java

@@ -23,11 +23,9 @@ import android.support.annotation.Nullable;
 import android.support.annotation.StringRes;
 import android.support.v4.app.NotificationCompat;
 import com.google.android.exoplayer2.C;
-import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadManager.TaskState;
-import com.google.android.exoplayer2.util.ErrorMessageProvider;
 
-/** Helper class to create notifications for downloads using {@link DownloadManager}. */
+/** Helper for creating download notifications. */
 public final class DownloadNotificationUtil {
 
   private static final @StringRes int NULL_STRING_ID = 0;
@@ -35,24 +33,24 @@ public final class DownloadNotificationUtil {
   private DownloadNotificationUtil() {}
 
   /**
-   * Returns a progress notification for the given {@link TaskState}s.
+   * Returns a progress notification for the given task states.
    *
-   * @param taskStates States of the downloads.
-   * @param context Used to access resources.
+   * @param context A context for accessing resources.
    * @param smallIcon A small icon for the notification.
    * @param channelId The id of the notification channel to use. Only required for API level 26 and
    *     above.
    * @param contentIntent An optional content intent to send when the notification is clicked.
    * @param message An optional message to display on the notification.
-   * @return A progress notification for the given {@link TaskState}s.
+   * @param taskStates The task states.
+   * @return The notification.
    */
-  public static @Nullable Notification createProgressNotification(
-      TaskState[] taskStates,
+  public static Notification buildProgressNotification(
       Context context,
       @DrawableRes int smallIcon,
       String channelId,
       @Nullable PendingIntent contentIntent,
-      @Nullable String message) {
+      @Nullable String message,
+      TaskState[] taskStates) {
     float totalPercentage = 0;
     int downloadTaskCount = 0;
     boolean allDownloadPercentagesUnknown = true;
@@ -75,7 +73,7 @@ public final class DownloadNotificationUtil {
             ? R.string.exo_download_downloading
             : (taskStates.length > 0 ? R.string.exo_download_removing : NULL_STRING_ID);
     NotificationCompat.Builder notificationBuilder =
-        createNotificationBuilder(
+        newNotificationBuilder(
             context, smallIcon, channelId, contentIntent, message, titleStringId);
 
     int progress = haveDownloadTasks ? (int) (totalPercentage / downloadTaskCount) : 0;
@@ -88,51 +86,52 @@ public final class DownloadNotificationUtil {
   }
 
   /**
-   * Returns a notification for a {@link TaskState} which is in either {@link TaskState#STATE_ENDED}
-   * or {@link TaskState#STATE_ERROR} states. Returns null if it's some other state or it's state of
-   * a remove action.
+   * Returns a notification for a completed download.
    *
-   * @param taskState State of the download.
-   * @param context Used to access resources.
+   * @param context A context for accessing resources.
    * @param smallIcon A small icon for the notifications.
    * @param channelId The id of the notification channel to use. Only required for API level 26 and
    *     above.
    * @param contentIntent An optional content intent to send when the notification is clicked.
    * @param message An optional message to display on the notification.
-   * @param errorMessageProvider An optional {@link ErrorMessageProvider} for translating download
-   *     errors into readable error messages. If not null and there is a download error then the
-   *     error message is displayed instead of {@code message}.
-   * @return A notification for a {@link TaskState} which is in either {@link TaskState#STATE_ENDED}
-   *     or {@link TaskState#STATE_ERROR} states. Returns null if it's some other state or it's
-   *     state of a remove action.
+   * @return The notification.
    */
-  public static @Nullable Notification createDownloadFinishedNotification(
-      TaskState taskState,
+  public static Notification buildDownloadCompletedNotification(
       Context context,
       @DrawableRes int smallIcon,
       String channelId,
       @Nullable PendingIntent contentIntent,
-      @Nullable String message,
-      @Nullable ErrorMessageProvider<Throwable> errorMessageProvider) {
-    if (taskState.action.isRemoveAction
-        || (taskState.state != TaskState.STATE_ENDED && taskState.state != TaskState.STATE_ERROR)) {
-      return null;
-    }
-    if (taskState.error != null && errorMessageProvider != null) {
-      message = errorMessageProvider.getErrorMessage(taskState.error).second;
-    }
-    @StringRes
-    int titleStringId =
-        taskState.state == TaskState.STATE_ENDED
-            ? R.string.exo_download_completed
-            : R.string.exo_download_failed;
-    NotificationCompat.Builder notificationBuilder =
-        createNotificationBuilder(
-            context, smallIcon, channelId, contentIntent, message, titleStringId);
-    return notificationBuilder.build();
+      @Nullable String message) {
+    int titleStringId = R.string.exo_download_completed;
+    return newNotificationBuilder(
+            context, smallIcon, channelId, contentIntent, message, titleStringId)
+        .build();
+  }
+
+  /**
+   * Returns a notification for a failed download.
+   *
+   * @param context A context for accessing resources.
+   * @param smallIcon A small icon for the notifications.
+   * @param channelId The id of the notification channel to use. Only required for API level 26 and
+   *     above.
+   * @param contentIntent An optional content intent to send when the notification is clicked.
+   * @param message An optional message to display on the notification.
+   * @return The notification.
+   */
+  public static Notification buildDownloadFailedNotification(
+      Context context,
+      @DrawableRes int smallIcon,
+      String channelId,
+      @Nullable PendingIntent contentIntent,
+      @Nullable String message) {
+    @StringRes int titleStringId = R.string.exo_download_failed;
+    return newNotificationBuilder(
+            context, smallIcon, channelId, contentIntent, message, titleStringId)
+        .build();
   }
 
-  private static NotificationCompat.Builder createNotificationBuilder(
+  private static NotificationCompat.Builder newNotificationBuilder(
       Context context,
       @DrawableRes int smallIcon,
       String channelId,