Add pauseAllRequests()

pauseAllRequests() can be called when the activity is in the background to reclaim memory used by the active bitmaps. As the caches are unaffected by this, returning to the activity and loading is still fast.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=177660869

Author: kurtn

library/src/main/java/com/bumptech/glide/RequestManager.java

@@ -205,6 +205,10 @@ public boolean isPaused() {
   /**
    * Cancels any in progress loads, but does not clear resources of completed loads.
    *
+   * <p>Note #{@link #resumeRequests()} must be called for any requests made before or while the
+   * manager is paused to complete. RequestManagers attached to Fragments and Activities
+   * automatically resume onStart().
+   *
    * @see #isPaused()
    * @see #resumeRequests()
    */
@@ -213,6 +217,27 @@ public void pauseRequests() {
     requestTracker.pauseRequests();
   }
 
+  /**
+   * Cancels any in progress loads and clears resources of completed loads.
+   *
+   * <p>Note #{@link #resumeRequests()} must be called for any requests made before or while the
+   * manager is paused to complete. RequestManagers attached to Fragments and Activities
+   * automatically resume onStart().
+   *
+   * <p>This will release the memory used by completed bitmaps but leaves them in any configured
+   * caches. When an #{@link android.app.Activity} receives #{@link
+   * android.app.Activity#onTrimMemory(int)} at a level of #{@link
+   * android.content.ComponentCallbacks2#TRIM_MEMORY_BACKGROUND} this is desirable in order to keep
+   * your process alive longer.
+   *
+   * @see #isPaused()
+   * @see #resumeRequests()
+   */
+  public void pauseAllRequests() {
+    Util.assertMainThread();
+    requestTracker.pauseAllRequests();
+  }
+
   /**
    * Performs {@link #pauseRequests()} recursively for all managers that are contextually
    * descendant to this manager based on the Activity/Fragment hierarchy:

library/src/main/java/com/bumptech/glide/manager/RequestTracker.java

@@ -97,6 +97,17 @@ public void pauseRequests() {
     }
   }
 
+  /** Stops any in progress requests and releases bitmaps associated with completed requests. */
+  public void pauseAllRequests() {
+    isPaused = true;
+    for (Request request : Util.getSnapshot(requests)) {
+      if (request.isRunning() || request.isComplete()) {
+        request.pause();
+        pendingRequests.add(request);
+      }
+    }
+  }
+
   /**
    * Starts any not yet completed or failed requests.
    */

library/src/test/java/com/bumptech/glide/manager/RequestTrackerTest.java

@@ -354,6 +354,26 @@ public void testReturnsFalseFromIsPausedWhenResumed() {
     assertFalse(tracker.isPaused());
   }
 
+  @Test
+  public void testPauseAllRequests_returnsTrueFromIsPaused() {
+    tracker.pauseAllRequests();
+    assertTrue(tracker.isPaused());
+  }
+
+  @Test
+  public void testPauseAllRequests_whenRequestComplete_pausesRequest() {
+    Request request = mock(Request.class);
+    when(request.isFailed()).thenReturn(false);
+    when(request.isComplete()).thenReturn(true);
+    tracker.addRequest(request);
+    tracker.pauseAllRequests();
+    verify(request).pause();
+
+    when(request.isComplete()).thenReturn(false);
+    tracker.resumeRequests();
+    verify(request).begin();
+  }
+
   private class ClearAndRemoveRequest implements Answer<Void> {
 
     private final Request toRemove;