Minor tweaks to recents thumbnails.

- Reducing the size of the recents thumbnails
- Skip persisting if we never update the last thumbnail
- Don't bother loading the last thumbnail file descriptor if we have it in memory
- Fixing warning in getting drawable from resource

Change-Id: Ieddaeac75a5e5d80876a9b6b1d50f7cc84c7d6fd

2 files changed, 19 insertions, 10 deletions

diff --git a/services/core/java/com/android/server/am/ActivityRecord.java b/services/core/java/com/android/server/am/ActivityRecord.java
index 24b7cb3..fcbe71e 100755
--- a/services/core/java/com/android/server/am/ActivityRecord.java
+++ b/services/core/java/com/android/server/am/ActivityRecord.java
@@ -773,8 +773,8 @@ final class ActivityRecord {
         if (newThumbnail != null) {
             if (ActivityManagerService.DEBUG_THUMBNAILS) Slog.i(ActivityManagerService.TAG,
                     "Setting thumbnail of " + this + " to " + newThumbnail);
-            task.setLastThumbnail(newThumbnail);
-            if (isPersistable()) {
+            boolean thumbnailUpdated = task.setLastThumbnail(newThumbnail);
+            if (thumbnailUpdated && isPersistable()) {
                 mStackSupervisor.mService.notifyTaskPersisterLocked(task, false);
             }
         }
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 2a8c6fb..d35e09f 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -386,15 +386,23 @@ final class TaskRecord {
         setNextAffiliate(null);
     }
 
-    void setLastThumbnail(Bitmap thumbnail) {
-        mLastThumbnail = thumbnail;
-        if (thumbnail == null) {
-            if (mLastThumbnailFile != null) {
-                mLastThumbnailFile.delete();
+    /**
+     * Sets the last thumbnail.
+     * @return whether the thumbnail was set
+     */
+    boolean setLastThumbnail(Bitmap thumbnail) {
+        if (mLastThumbnail != thumbnail) {
+            mLastThumbnail = thumbnail;
+            if (thumbnail == null) {
+                if (mLastThumbnailFile != null) {
+                    mLastThumbnailFile.delete();
+                }
+            } else {
+                mService.mTaskPersister.saveImage(thumbnail, mFilename);
             }
-        } else {
-            mService.mTaskPersister.saveImage(thumbnail, mFilename);
+            return true;
         }
+        return false;
     }
 
     void getLastThumbnail(TaskThumbnail thumbs) {
@@ -403,7 +411,8 @@ final class TaskRecord {
         if (mLastThumbnail == null) {
             thumbs.mainThumbnail = mService.mTaskPersister.getThumbnail(mFilename);
         }
-        if (mLastThumbnailFile.exists()) {
+        // Only load the thumbnail file if we don't have a thumbnail
+        if (thumbs.mainThumbnail == null && mLastThumbnailFile.exists()) {
             try {
                 thumbs.thumbnailFileDescriptor = ParcelFileDescriptor.open(mLastThumbnailFile,
                         ParcelFileDescriptor.MODE_READ_ONLY);