commit fbe47df2a41e467db92ad86432b8b726e9e79409
author chaviw <chaviw@google.com> Fri Nov 10 16:14:49 2017 -0800
committer chaviw <chaviw@google.com> Tue Nov 28 10:52:43 2017 -0800
tree 99363e31a680e90bbd79c5727e95c1bd00522205
parent 6f45a394c55e7b2cfe58e52da3a2254e70d71e54

Snapshot Task with the app window crop for Recents

Snapshot a specific task and its children instead of taking a snapshot
of the whole screen with max and min layer values. This makes it clear
what the desired screenshot is instead of trying to determine what the
max and min z layers should be.

In the process of updating the snapshot code, I split the code that
captures a layer from the code that captures the whole screen. This
simplified the code so the capture screen doesn't need to invoke the
frame calculations since it will be capturing the whole screen anyway.

Test: Recents snapshots work correctly without the IME, status, and
navigation bar

Change-Id: I8776c1ddb9cd8a23a482b045720960702796fd5f

services/core/java/com/android/server/wm/TaskSnapshotController.java

diff --git a/services/core/java/com/android/server/wm/TaskSnapshotController.java b/services/core/java/com/android/server/wm/TaskSnapshotController.java
index e644417..84e475a 100644
--- a/services/core/java/com/android/server/wm/TaskSnapshotController.java
+++ b/services/core/java/com/android/server/wm/TaskSnapshotController.java
@@ -18,12 +18,12 @@
 
 import static com.android.server.wm.TaskSnapshotPersister.DISABLE_FULL_SIZED_BITMAPS;
 import static com.android.server.wm.TaskSnapshotPersister.REDUCED_SCALE;
+import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_SCREENSHOT;
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
 
 import android.annotation.Nullable;
 import android.app.ActivityManager;
-import android.app.ActivityManager.StackId;
 import android.app.ActivityManager.TaskSnapshot;
 import android.content.pm.PackageManager;
 import android.graphics.Bitmap;
@@ -35,6 +35,7 @@
 import android.util.Slog;
 import android.view.DisplayListCanvas;
 import android.view.RenderNode;
+import android.view.SurfaceControl;
 import android.view.ThreadedRenderer;
 import android.view.WindowManager.LayoutParams;
 
@@ -210,11 +211,28 @@
         if (mainWindow == null) {
             return null;
         }
+        if (!mService.mPolicy.isScreenOn()) {
+            if (DEBUG_SCREENSHOT) {
+                Slog.i(TAG_WM, "Attempted to take screenshot while display was off.");
+            }
+            return null;
+        }
+        if (task.getSurfaceControl() == null) {
+            return null;
+        }
+
         final boolean isLowRamDevice = ActivityManager.isLowRamDeviceStatic();
         final float scaleFraction = isLowRamDevice ? REDUCED_SCALE : 1f;
-        final GraphicBuffer buffer = top.mDisplayContent.screenshotApplicationsToBuffer(top.token,
-                -1, -1, false, scaleFraction, false, true);
+        final Rect taskFrame = new Rect();
+        task.getBounds(taskFrame);
+
+        final GraphicBuffer buffer = SurfaceControl.captureLayersToBuffer(
+                task.getSurfaceControl().getHandle(), taskFrame, scaleFraction);
+
         if (buffer == null || buffer.getWidth() <= 1 || buffer.getHeight() <= 1) {
+            if (DEBUG_SCREENSHOT) {
+                Slog.w(TAG_WM, "Failed to take screenshot");
+            }
             return null;
         }
         return new TaskSnapshot(buffer, top.getConfiguration().orientation,