Downscale oversized MessagingStyle avatars

Notification API downscales oversized icons in all formats except in MessagingStyle. This seems to be an oversight that can cause massive memory usage.
This downscales avatars to a reasonable size if they're too big.

Bug:193720474
Bug:221890932

Test: atest NotificationTest
      Built a test app with 4000x4000 avatar icon.
      Memory usage went from 250MB to ~170KB per notification.
Change-Id: I35377cdb5d61ee6e23fccc2bffb5d3aec6ca2b7d

1 files changed, 47 insertions, 0 deletions

diff --git a/core/java/android/app/Notification.java b/core/java/android/app/Notification.java
index 6e1d1cd2e4c9..6bb35db6e712 100644
--- a/core/java/android/app/Notification.java
+++ b/core/java/android/app/Notification.java
@@ -7917,6 +7917,8 @@ public class Notification implements Parcelable
          * @hide
          */
         public MessagingStyle setShortcutIcon(@Nullable Icon conversationIcon) {
+            // TODO(b/228941516): This icon should be downscaled to avoid using too much memory,
+            // see reduceImageSizes.
             mShortcutIcon = conversationIcon;
             return this;
         }
@@ -8423,6 +8425,51 @@ public class Notification implements Parcelable
             return makeMessagingView(StandardTemplateParams.VIEW_TYPE_HEADS_UP);
         }
 
+        /**
+         * @hide
+         */
+        @Override
+        public void reduceImageSizes(Context context) {
+            super.reduceImageSizes(context);
+            Resources resources = context.getResources();
+            boolean isLowRam = ActivityManager.isLowRamDeviceStatic();
+            if (mShortcutIcon != null) {
+                int maxSize = resources.getDimensionPixelSize(
+                        isLowRam ? R.dimen.notification_small_icon_size_low_ram
+                                : R.dimen.notification_small_icon_size);
+                mShortcutIcon.scaleDownIfNecessary(maxSize, maxSize);
+            }
+
+            int maxAvatarSize = resources.getDimensionPixelSize(
+                    isLowRam ? R.dimen.notification_person_icon_max_size
+                            : R.dimen.notification_person_icon_max_size_low_ram);
+            if (mUser != null && mUser.getIcon() != null) {
+                mUser.getIcon().scaleDownIfNecessary(maxAvatarSize, maxAvatarSize);
+            }
+
+            reduceMessagesIconSizes(mMessages, maxAvatarSize);
+            reduceMessagesIconSizes(mHistoricMessages, maxAvatarSize);
+        }
+
+        /**
+         * @hide
+         */
+        private static void reduceMessagesIconSizes(@Nullable List<Message> messages, int maxSize) {
+            if (messages == null) {
+                return;
+            }
+
+            for (Message message : messages) {
+                Person sender = message.mSender;
+                if (sender != null) {
+                    Icon icon = sender.getIcon();
+                    if (icon != null) {
+                        icon.scaleDownIfNecessary(maxSize, maxSize);
+                    }
+                }
+            }
+        }
+
         public static final class Message {
             /** @hide */
             public static final String KEY_TEXT = "text";