Take snapshot when screen is turning off
Since we can't take a snapshot when screen is turned off, we need
to snapshot before we are turning the screen off. For this, we
- Add a callback from DisplayPowerController to give policy a
chance to do something before display will be turned off.
- Implement this callback by taking snapshots of all visible
tasks.
Test: Inspect logs/traces about screen off blocking to make sure
callback is working correctly.
Test: Insert artificial 500ms delay in onScreenTurningOff and make
sure we are unblocking screen off when turning on screen in the
meantime.
Test: Open Maps, go to recents, open maps again, scroll to another
location, toggle power button, make sure the old location isn't
shown during unlock.
Change-Id: I489f31358f838d418f894f996495946084f136a4
Fixes: 37107783
diff --git a/services/core/java/com/android/server/wm/TaskSnapshotController.java b/services/core/java/com/android/server/wm/TaskSnapshotController.java
index 1bbe1d0..24cb464 100644
--- a/services/core/java/com/android/server/wm/TaskSnapshotController.java
+++ b/services/core/java/com/android/server/wm/TaskSnapshotController.java
@@ -30,8 +30,10 @@
import android.graphics.GraphicBuffer;
import android.graphics.Rect;
import android.os.Environment;
+import android.os.Handler;
import android.util.ArraySet;
import android.view.WindowManager.LayoutParams;
+import android.view.WindowManagerPolicy.ScreenOffListener;
import android.view.WindowManagerPolicy.StartingSurface;
import com.google.android.collect.Sets;
@@ -40,6 +42,7 @@
import com.android.server.wm.TaskSnapshotSurface.SystemBarBackgroundPainter;
import java.io.PrintWriter;
+import java.util.function.Consumer;
/**
* When an app token becomes invisible, we take a snapshot (bitmap) of the corresponding task and
@@ -83,6 +86,7 @@
Environment::getDataSystemCeDirectory);
private final TaskSnapshotLoader mLoader = new TaskSnapshotLoader(mPersister);
private final ArraySet<Task> mTmpTasks = new ArraySet<>();
+ private final Handler mHandler = new Handler();
TaskSnapshotController(WindowManagerService service) {
mService = service;
@@ -114,8 +118,13 @@
// We need to take a snapshot of the task if and only if all activities of the task are
// either closing or hidden.
getClosingTasks(closingApps, mTmpTasks);
- for (int i = mTmpTasks.size() - 1; i >= 0; i--) {
- final Task task = mTmpTasks.valueAt(i);
+ snapshotTasks(mTmpTasks);
+
+ }
+
+ private void snapshotTasks(ArraySet<Task> tasks) {
+ for (int i = tasks.size() - 1; i >= 0; i--) {
+ final Task task = tasks.valueAt(i);
final int mode = getSnapshotMode(task);
final TaskSnapshot snapshot;
switch (mode) {
@@ -284,6 +293,33 @@
mPersister.setPaused(paused);
}
+ /**
+ * Called when screen is being turned off.
+ */
+ void screenTurningOff(ScreenOffListener listener) {
+ if (!ENABLE_TASK_SNAPSHOTS || ActivityManager.isLowRamDeviceStatic()) {
+ listener.onScreenOff();
+ return;
+ }
+
+ // We can't take a snapshot when screen is off, so take a snapshot now!
+ mHandler.post(() -> {
+ try {
+ synchronized (mService.mWindowMap) {
+ mTmpTasks.clear();
+ mService.mRoot.forAllTasks(task -> {
+ if (task.isVisible()) {
+ mTmpTasks.add(task);
+ }
+ });
+ snapshotTasks(mTmpTasks);
+ }
+ } finally {
+ listener.onScreenOff();
+ }
+ });
+ }
+
void dump(PrintWriter pw, String prefix) {
mCache.dump(pw, prefix);
}