From 8a094e972e686ddd1223371c268f0a4758e0b1ef Mon Sep 17 00:00:00 2001
From: Sam Judd <judds@google.com>
Date: Tue, 13 Aug 2019 13:47:44 -0700
Subject: [PATCH] Adds support to more aggressively pause in progress and
 completed requests in Glide in response to an onTrimMemory event.

PiperOrigin-RevId: 263206711
---
 .../main/java/com/bumptech/glide/Glide.java   |  5 ++
 .../com/bumptech/glide/RequestManager.java    | 46 ++++++++++++++++++-
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/library/src/main/java/com/bumptech/glide/Glide.java b/library/src/main/java/com/bumptech/glide/Glide.java
index 4ef954d7ed..20a2be95a0 100644
--- a/library/src/main/java/com/bumptech/glide/Glide.java
+++ b/library/src/main/java/com/bumptech/glide/Glide.java
@@ -648,6 +648,11 @@ public void clearMemory() {
   public void trimMemory(int level) {
     // Engine asserts this anyway when removing resources, fail faster and consistently
     Util.assertMainThread();
+    // Request managers need to be trimmed before the caches and pools, in order for the latter to
+    // have the most benefit.
+    for (RequestManager manager : managers) {
+      manager.onTrimMemory(level);
+    }
     // memory cache needs to be trimmed before bitmap pool to trim re-pooled Bitmaps too. See #687.
     memoryCache.trimMemory(level);
     bitmapPool.trimMemory(level);
diff --git a/library/src/main/java/com/bumptech/glide/RequestManager.java b/library/src/main/java/com/bumptech/glide/RequestManager.java
index a33e2b9ec4..cd6b528c5c 100644
--- a/library/src/main/java/com/bumptech/glide/RequestManager.java
+++ b/library/src/main/java/com/bumptech/glide/RequestManager.java
@@ -4,7 +4,9 @@
 import static com.bumptech.glide.request.RequestOptions.diskCacheStrategyOf;
 import static com.bumptech.glide.request.RequestOptions.skipMemoryCacheOf;
 
+import android.content.ComponentCallbacks2;
 import android.content.Context;
+import android.content.res.Configuration;
 import android.graphics.Bitmap;
 import android.graphics.drawable.Drawable;
 import android.net.Uri;
@@ -54,7 +56,8 @@
  * @see Glide#with(androidx.fragment.app.Fragment)
  * @see Glide#with(Context)
  */
-public class RequestManager implements LifecycleListener, ModelTypes<RequestBuilder<Drawable>> {
+public class RequestManager
+    implements ComponentCallbacks2, LifecycleListener, ModelTypes<RequestBuilder<Drawable>> {
   private static final RequestOptions DECODE_TYPE_BITMAP = decodeTypeOf(Bitmap.class).lock();
   private static final RequestOptions DECODE_TYPE_GIF = decodeTypeOf(GifDrawable.class).lock();
   private static final RequestOptions DOWNLOAD_ONLY_OPTIONS =
@@ -93,6 +96,8 @@ public void run() {
   @GuardedBy("this")
   private RequestOptions requestOptions;
 
+  private boolean pauseAllRequestsOnTrimMemoryModerate;
+
   public RequestManager(
       @NonNull Glide glide,
       @NonNull Lifecycle lifecycle,
@@ -221,6 +226,14 @@ public RequestManager addDefaultRequestListener(RequestListener<Object> requestL
     return this;
   }
 
+  /**
+   * If {@code true} then clear all in-progress and completed requests when the platform sends
+   * {@code onTrimMemory} with level = {@code TRIM_MEMORY_MODERATE}.
+   */
+  public void setPauseAllRequestsOnTrimMemoryModerate(boolean pauseAllOnTrim) {
+    pauseAllRequestsOnTrimMemoryModerate = pauseAllOnTrim;
+  }
+
   /**
    * Returns true if loads for this {@link RequestManager} are currently paused.
    *
@@ -265,6 +278,22 @@ public synchronized void pauseAllRequests() {
     requestTracker.pauseAllRequests();
   }
 
+  /**
+   * Performs {@link #pauseAllRequests()} recursively for all managers that are contextually
+   * descendant to this manager based on the Activity/Fragment hierarchy.
+   *
+   * <p>Similar to {@link #pauseRequestsRecursive()} with the exception that it also clears
+   * resources of completed loads.
+   */
+  // Public API.
+  @SuppressWarnings({"WeakerAccess", "unused"})
+  public synchronized void pauseAllRequestsRecursive() {
+    pauseAllRequests();
+    for (RequestManager requestManager : treeNode.getDescendants()) {
+      requestManager.pauseAllRequests();
+    }
+  }
+
   /**
    * Performs {@link #pauseRequests()} recursively for all managers that are contextually descendant
    * to this manager based on the Activity/Fragment hierarchy:
@@ -663,6 +692,21 @@ public synchronized String toString() {
     return super.toString() + "{tracker=" + requestTracker + ", treeNode=" + treeNode + "}";
   }
 
+  @Override
+  public void onTrimMemory(int level) {
+    if (level == TRIM_MEMORY_MODERATE && pauseAllRequestsOnTrimMemoryModerate) {
+      pauseAllRequestsRecursive();
+    }
+  }
+
+  @Override
+  public void onLowMemory() {
+    // Nothing to add conditionally. See Glide#onTrimMemory for unconditional behavior.
+  }
+
+  @Override
+  public void onConfigurationChanged(Configuration newConfig) {}
+
   private class RequestManagerConnectivityListener
       implements ConnectivityMonitor.ConnectivityListener {
     @GuardedBy("RequestManager.this")