Make DownloadManager watch requirements directly

PiperOrigin-RevId: 229544734

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

@@ -101,10 +101,12 @@ public class DemoApplication extends Application {
           new DownloaderConstructorHelper(getDownloadCache(), buildHttpDataSourceFactory());
       downloadManager =
           new DownloadManager(
+              this,
               new File(getDownloadDirectory(), DOWNLOAD_ACTION_FILE),
               new DefaultDownloaderFactory(downloaderConstructorHelper),
               MAX_SIMULTANEOUS_DOWNLOADS,
-              DownloadManager.DEFAULT_MIN_RETRY_COUNT);
+              DownloadManager.DEFAULT_MIN_RETRY_COUNT,
+              DownloadManager.DEFAULT_REQUIREMENTS);
       downloadTracker =
           new DownloadTracker(
               /* context= */ this,

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

@@ -41,6 +41,7 @@ import com.google.android.exoplayer2.offline.DownloadService;
 import com.google.android.exoplayer2.offline.DownloadState;
 import com.google.android.exoplayer2.offline.ProgressiveDownloadHelper;
 import com.google.android.exoplayer2.offline.StreamKey;
+import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.source.dash.offline.DashDownloadHelper;
 import com.google.android.exoplayer2.source.hls.offline.HlsDownloadHelper;
@@ -159,6 +160,14 @@ public class DownloadTracker implements DownloadManager.Listener {
     // 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

@@ -28,12 +28,15 @@ import static com.google.android.exoplayer2.offline.DownloadState.STATE_STOPPED;
 import static com.google.android.exoplayer2.offline.DownloadState.STOP_FLAG_DOWNLOAD_MANAGER_NOT_READY;
 import static com.google.android.exoplayer2.offline.DownloadState.STOP_FLAG_STOPPED;
 
+import android.content.Context;
 import android.os.ConditionVariable;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
 import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.scheduler.Requirements;
+import com.google.android.exoplayer2.scheduler.RequirementsWatcher;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import java.io.File;
@@ -74,18 +77,35 @@ public final class DownloadManager {
      * @param downloadManager The reporting instance.
      */
     void onIdle(DownloadManager downloadManager);
+
+    /**
+     * Called when the download requirements state changed.
+     *
+     * @param downloadManager The reporting instance.
+     * @param requirements Requirements needed to be met to start downloads.
+     * @param notMetRequirements {@link Requirements.RequirementFlags RequirementFlags} that are not
+     *     met, or 0.
+     */
+    void onRequirementsStateChanged(
+        DownloadManager downloadManager,
+        Requirements requirements,
+        @Requirements.RequirementFlags int notMetRequirements);
   }
 
   /** The default maximum number of simultaneous downloads. */
   public static final int DEFAULT_MAX_SIMULTANEOUS_DOWNLOADS = 1;
   /** The default minimum number of times a download must be retried before failing. */
   public static final int DEFAULT_MIN_RETRY_COUNT = 5;
+  /** The default requirement is that the device has network connectivity. */
+  public static final Requirements DEFAULT_REQUIREMENTS =
+      new Requirements(Requirements.NETWORK_TYPE_ANY, false, false);
 
   private static final String TAG = "DownloadManager";
   private static final boolean DEBUG = false;
 
   private final int maxActiveDownloads;
   private final int minRetryCount;
+  private final Context context;
   private final ActionFile actionFile;
   private final DownloaderFactory downloaderFactory;
   private final ArrayList<Download> downloads;
@@ -99,31 +119,43 @@ public final class DownloadManager {
   private boolean initialized;
   private boolean released;
   @DownloadState.StopFlags private int stickyStopFlags;
+  private RequirementsWatcher requirementsWatcher;
 
   /**
    * Constructs a {@link DownloadManager}.
    *
+   * @param context Any context.
    * @param actionFile The file in which active actions are saved.
    * @param downloaderFactory A factory for creating {@link Downloader}s.
    */
-  public DownloadManager(File actionFile, DownloaderFactory downloaderFactory) {
+  public DownloadManager(Context context, File actionFile, DownloaderFactory downloaderFactory) {
     this(
-        actionFile, downloaderFactory, DEFAULT_MAX_SIMULTANEOUS_DOWNLOADS, DEFAULT_MIN_RETRY_COUNT);
+        context,
+        actionFile,
+        downloaderFactory,
+        DEFAULT_MAX_SIMULTANEOUS_DOWNLOADS,
+        DEFAULT_MIN_RETRY_COUNT,
+        DEFAULT_REQUIREMENTS);
   }
 
   /**
    * Constructs a {@link DownloadManager}.
    *
+   * @param context Any context.
    * @param actionFile The file in which active actions are saved.
    * @param downloaderFactory A factory for creating {@link Downloader}s.
    * @param maxSimultaneousDownloads The maximum number of simultaneous downloads.
    * @param minRetryCount The minimum number of times a download must be retried before failing.
+   * @param requirements The requirements needed to be met to start downloads.
    */
   public DownloadManager(
+      Context context,
       File actionFile,
       DownloaderFactory downloaderFactory,
       int maxSimultaneousDownloads,
-      int minRetryCount) {
+      int minRetryCount,
+      Requirements requirements) {
+    this.context = context.getApplicationContext();
     this.actionFile = new ActionFile(actionFile);
     this.downloaderFactory = downloaderFactory;
     this.maxActiveDownloads = maxSimultaneousDownloads;
@@ -146,11 +178,31 @@ public final class DownloadManager {
     listeners = new CopyOnWriteArraySet<>();
     actionQueue = new ArrayDeque<>();
 
+    watchRequirements(requirements);
     loadActions();
     logd("Created");
   }
 
   /**
+   * Sets the requirements needed to be met to start downloads.
+   *
+   * @param requirements Need to be met to start downloads.
+   */
+  public void setRequirements(Requirements requirements) {
+    Assertions.checkState(!released);
+    if (requirements.equals(requirementsWatcher.getRequirements())) {
+      return;
+    }
+    requirementsWatcher.stop();
+    notifyListenersRequirementsStateChange(watchRequirements(requirements));
+  }
+
+  /** Returns the requirements needed to be met to start downloads. */
+  public Requirements getRequirements() {
+    return requirementsWatcher.getRequirements();
+  }
+
+  /**
    * Adds a {@link Listener}.
    *
    * @param listener The listener to be added.
@@ -278,6 +330,9 @@ public final class DownloadManager {
     }
     setStopFlags(STOP_FLAG_DOWNLOAD_MANAGER_NOT_READY);
     released = true;
+    if (requirementsWatcher != null) {
+      requirementsWatcher.stop();
+    }
     final ConditionVariable fileIOFinishedCondition = new ConditionVariable();
     fileIOHandler.post(fileIOFinishedCondition::open);
     fileIOFinishedCondition.block();
@@ -346,6 +401,15 @@ public final class DownloadManager {
     }
   }
 
+  private void notifyListenersRequirementsStateChange(
+      @Requirements.RequirementFlags int notMetRequirements) {
+    logdFlags("Not met requirements are changed", notMetRequirements);
+    for (Listener listener : listeners) {
+      listener.onRequirementsStateChanged(
+          DownloadManager.this, requirementsWatcher.getRequirements(), notMetRequirements);
+    }
+  }
+
   private void loadActions() {
     fileIOHandler.post(
         () -> {
@@ -420,6 +484,18 @@ public final class DownloadManager {
     }
   }
 
+  @Requirements.RequirementFlags
+  private int watchRequirements(Requirements requirements) {
+    requirementsWatcher = new RequirementsWatcher(context, new RequirementListener(), requirements);
+    @Requirements.RequirementFlags int notMetRequirements = requirementsWatcher.start();
+    if (notMetRequirements == 0) {
+      startDownloads();
+    } else {
+      stopDownloads();
+    }
+    return notMetRequirements;
+  }
+
   private static final class Download {
 
     private final String id;
@@ -693,4 +769,20 @@ public final class DownloadManager {
       return Math.min((errorCount - 1) * 1000, 5000);
     }
   }
+
+  private class RequirementListener implements RequirementsWatcher.Listener {
+    @Override
+    public void requirementsMet(RequirementsWatcher requirementsWatcher) {
+      startDownloads();
+      notifyListenersRequirementsStateChange(0);
+    }
+
+    @Override
+    public void requirementsNotMet(
+        RequirementsWatcher requirementsWatcher,
+        @Requirements.RequirementFlags int notMetRequirements) {
+      stopDownloads();
+      notifyListenersRequirementsStateChange(notMetRequirements);
+    }
+  }
 }

library/core/src/main/java/com/google/android/exoplayer2/scheduler/Requirements.java

@@ -155,16 +155,14 @@ public final class Requirements {
    * @return Whether the requirements are met.
    */
   public boolean checkRequirements(Context context) {
-    return checkNetworkRequirements(context)
-        && checkChargingRequirement(context)
-        && checkIdleRequirement(context);
+    return getNotMetRequirements(context) == 0;
   }
 
   /**
-   * Returns the requirement flags that are not met, or 0.
+   * Returns {@link RequirementFlags} that are not met, or 0.
    *
    * @param context Any context.
-   * @return The requirement flags that are not met, or 0.
+   * @return RequirementFlags that are not met, or 0.
    */
   @RequirementFlags
   public int getNotMetRequirements(Context context) {
@@ -285,4 +283,20 @@ public final class Requirements {
         + (isIdleRequired() ? ",idle" : "")
         + '}';
   }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+    return requirements == ((Requirements) o).requirements;
+  }
+
+  @Override
+  public int hashCode() {
+    return requirements;
+  }
 }

library/core/src/main/java/com/google/android/exoplayer2/scheduler/RequirementsWatcher.java

@@ -55,8 +55,12 @@ public final class RequirementsWatcher {
      * requirements are not met.
      *
      * @param requirementsWatcher Calling instance.
+     * @param notMetRequirements {@link Requirements.RequirementFlags RequirementFlags} that are not
+     *     met, or 0.
      */
-    void requirementsNotMet(RequirementsWatcher requirementsWatcher);
+    void requirementsNotMet(
+        RequirementsWatcher requirementsWatcher,
+        @Requirements.RequirementFlags int notMetRequirements);
   }
 
   private static final String TAG = "RequirementsWatcher";
@@ -66,7 +70,7 @@ public final class RequirementsWatcher {
   private final Requirements requirements;
   private DeviceStatusChangeReceiver receiver;
 
-  private int notMetRequirements;
+  @Requirements.RequirementFlags private int notMetRequirements;
   private CapabilityValidatedCallback networkCallback;
   private Handler handler;
 
@@ -85,8 +89,11 @@ public final class RequirementsWatcher {
   /**
    * Starts watching for changes. Must be called from a thread that has an associated {@link
    * Looper}. Listener methods are called on the caller thread.
+   *
+   * @return Initial {@link Requirements.RequirementFlags RequirementFlags} that are not met, or 0.
    */
-  public void start() {
+  @Requirements.RequirementFlags
+  public int start() {
     Assertions.checkNotNull(Looper.myLooper());
     handler = new Handler();
 
@@ -115,6 +122,7 @@ public final class RequirementsWatcher {
     receiver = new DeviceStatusChangeReceiver();
     context.registerReceiver(receiver, filter, null, handler);
     logd(this + " started");
+    return notMetRequirements;
   }
 
   /** Stops watching for changes. */
@@ -162,6 +170,7 @@ public final class RequirementsWatcher {
   }
 
   private void checkRequirements() {
+    @Requirements.RequirementFlags
     int notMetRequirements = requirements.getNotMetRequirements(context);
     if (this.notMetRequirements == notMetRequirements) {
       logd("notMetRequirements hasn't changed: " + notMetRequirements);
@@ -173,7 +182,7 @@ public final class RequirementsWatcher {
       listener.requirementsMet(this);
     } else {
       logd("stop job");
-      listener.requirementsNotMet(this);
+      listener.requirementsNotMet(this, notMetRequirements);
     }
   }
 

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

@@ -21,6 +21,7 @@ import static org.junit.Assert.fail;
 import android.net.Uri;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.offline.DownloadState.State;
+import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.testutil.DummyMainThread;
 import com.google.android.exoplayer2.testutil.RobolectricUtil;
 import com.google.android.exoplayer2.testutil.TestDownloadManagerListener;
@@ -426,7 +427,12 @@ public class DownloadManagerTest {
           () -> {
             downloadManager =
                 new DownloadManager(
-                    actionFile, downloaderFactory, maxActiveDownloadTasks, MIN_RETRY_COUNT);
+                    RuntimeEnvironment.application,
+                    actionFile,
+                    downloaderFactory,
+                    maxActiveDownloadTasks,
+                    MIN_RETRY_COUNT,
+                    new Requirements(0));
             downloadManagerListener =
                 new TestDownloadManagerListener(downloadManager, dummyMainThread);
             downloadManager.startDownloads();

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

@@ -30,6 +30,7 @@ import com.google.android.exoplayer2.offline.DownloadAction;
 import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloaderConstructorHelper;
 import com.google.android.exoplayer2.offline.StreamKey;
+import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.testutil.DummyMainThread;
 import com.google.android.exoplayer2.testutil.FakeDataSet;
 import com.google.android.exoplayer2.testutil.FakeDataSource;
@@ -241,11 +242,13 @@ public class DownloadManagerDashTest {
           Factory fakeDataSourceFactory = new FakeDataSource.Factory().setFakeDataSet(fakeDataSet);
           downloadManager =
               new DownloadManager(
+                  RuntimeEnvironment.application,
                   actionFile,
                   new DefaultDownloaderFactory(
                       new DownloaderConstructorHelper(cache, fakeDataSourceFactory)),
                   /* maxSimultaneousDownloads= */ 1,
-                  /* minRetryCount= */ 3);
+                  /* minRetryCount= */ 3,
+                  new Requirements(0));
 
           downloadManagerListener =
               new TestDownloadManagerListener(downloadManager, dummyMainThread);

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

@@ -30,6 +30,7 @@ import com.google.android.exoplayer2.offline.DownloadManager;
 import com.google.android.exoplayer2.offline.DownloadService;
 import com.google.android.exoplayer2.offline.DownloaderConstructorHelper;
 import com.google.android.exoplayer2.offline.StreamKey;
+import com.google.android.exoplayer2.scheduler.Requirements;
 import com.google.android.exoplayer2.scheduler.Scheduler;
 import com.google.android.exoplayer2.testutil.DummyMainThread;
 import com.google.android.exoplayer2.testutil.FakeDataSet;
@@ -117,11 +118,13 @@ public class DownloadServiceDashTest {
           actionFile.delete();
           final DownloadManager dashDownloadManager =
               new DownloadManager(
+                  RuntimeEnvironment.application,
                   actionFile,
                   new DefaultDownloaderFactory(
                       new DownloaderConstructorHelper(cache, fakeDataSourceFactory)),
                   /* maxSimultaneousDownloads= */ 1,
-                  /* minRetryCount= */ 3);
+                  /* minRetryCount= */ 3,
+                  new Requirements(0));
           downloadManagerListener =
               new TestDownloadManagerListener(dashDownloadManager, dummyMainThread);
           dashDownloadManager.startDownloads();

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

@@ -20,6 +20,7 @@ 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;
@@ -82,6 +83,12 @@ 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.