commit ff9b4dff6c62f8b6a950edfdd2c136b697c612ad
author Charles He <qiurui@google.com> Fri Sep 22 10:18:37 2017 +0100
committer Charles He <qiurui@google.com> Mon Oct 30 13:35:08 2017 +0000
tree 83d52071c408f7ccf245f18ce648b7bba5bd5d83
parent ab57e18da1b249db29e54ce33ad58117652a7e0d

AM: make LockTask truly multi-task-aware.

LockTask was first designed to be single-task only. It was later
expanded to multi-task use cases in a rather flawed manner. Many aspects
of the implementation overlook the implications of more than one locked
tasks, and sometimes completely ignore the LockTask-unaware apps.

For example, LockTask-unaware apps are not registered in
LockTaskController's list of locked tasks, although they can be launched
in LockTask mode as long as they are whitelisted. As a consequence,
these unregistered tasks are not finished when their whitelist
authorization is removed.

In this patch, we make sure LockTask-unaware apps are also registered,
and introduce the notion of a root task, thus providing a genuine
multi-task experience with LockTask.

Bug: 66130096
Bug: 66132035
Test: bit FrameworksServicesTests:com.android.server.am.LockTaskControllerTest
Test: cts-tradefed run cts-dev -m DevicePolicyManager --test com.android.cts.devicepolicy.DeviceOwnerTest#testLockTask_deviceOwnerUser
Test: manual, by using TestDPC > Start kiosk mode
Change-Id: I68a26d2198fa3991f85ae1e7a6acae5981c34db5

services/core/java/com/android/server/am/ActivityStackSupervisor.java

diff --git a/services/core/java/com/android/server/am/ActivityStackSupervisor.java b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
index 6ec158e..1ee946b 100644
--- a/services/core/java/com/android/server/am/ActivityStackSupervisor.java
+++ b/services/core/java/com/android/server/am/ActivityStackSupervisor.java
@@ -20,6 +20,7 @@
 import static android.Manifest.permission.INTERNAL_SYSTEM_WINDOW;
 import static android.Manifest.permission.START_ANY_ACTIVITY;
 import static android.Manifest.permission.START_TASKS_FROM_RECENTS;
+import static android.app.ActivityManager.LOCK_TASK_MODE_LOCKED;
 import static android.app.ActivityManager.START_TASK_TO_FRONT;
 import static android.app.ActivityManager.StackId.INVALID_STACK_ID;
 import static android.app.ITaskStackListener.FORCED_RESIZEABLE_REASON_SECONDARY_DISPLAY;
@@ -83,6 +84,7 @@
 import static com.android.server.am.TaskRecord.INVALID_TASK_ID;
 import static com.android.server.am.TaskRecord.LOCK_TASK_AUTH_LAUNCHABLE;
 import static com.android.server.am.TaskRecord.LOCK_TASK_AUTH_LAUNCHABLE_PRIV;
+import static com.android.server.am.TaskRecord.LOCK_TASK_AUTH_WHITELISTED;
 import static com.android.server.am.TaskRecord.REPARENT_KEEP_STACK_AT_FRONT;
 import static com.android.server.am.TaskRecord.REPARENT_LEAVE_STACK_IN_PLACE;
 import static com.android.server.am.TaskRecord.REPARENT_MOVE_STACK_TO_FRONT;
@@ -1306,8 +1308,11 @@
             mService.updateLruProcessLocked(app, true, null);
             mService.updateOomAdjLocked();
 
-            if (task.mLockTaskAuth == LOCK_TASK_AUTH_LAUNCHABLE ||
-                    task.mLockTaskAuth == LOCK_TASK_AUTH_LAUNCHABLE_PRIV) {
+            if (task.mLockTaskAuth == LOCK_TASK_AUTH_LAUNCHABLE
+                    || task.mLockTaskAuth == LOCK_TASK_AUTH_LAUNCHABLE_PRIV
+                    || (task.mLockTaskAuth == LOCK_TASK_AUTH_WHITELISTED
+                            && mService.mLockTaskController.getLockTaskModeState()
+                            == LOCK_TASK_MODE_LOCKED)) {
                 mService.mLockTaskController.startLockTaskMode(task, false, 0 /* blank UID */);
             }
 
@@ -2769,6 +2774,7 @@
         if (tr != null) {
             tr.removeTaskActivitiesLocked(pauseImmediately);
             cleanUpRemovedTaskLocked(tr, killProcess, removeFromRecents);
+            mService.mLockTaskController.clearLockedTask(tr);
             if (tr.isPersistable) {
                 mService.notifyTaskPersisterLocked(null, true);
             }