From 7dcbfb02c9bd1e6ba05168637c8c5b66f95696db Mon Sep 17 00:00:00 2001
From: Benjamin Franz <bfranz@google.com>
Date: Tue, 16 Jan 2018 15:16:16 +0000
Subject: [PATCH] Block root task from being shown in recents

Do not show the root task of lock task mode in recents and thereby block
it from being swiped away.

Bug: 70332786
Test: manual
Change-Id: I529c2896faae6b6d94ba3b758d15f40d83fb8573
---
 .../java/com/android/server/am/LockTaskController.java | 10 ++++++++++
 .../core/java/com/android/server/am/RecentTasks.java   |  5 +++++
 2 files changed, 15 insertions(+)

diff --git a/services/core/java/com/android/server/am/LockTaskController.java b/services/core/java/com/android/server/am/LockTaskController.java
index ed39329844ef4..7eb0bf4bb0a88 100644
--- a/services/core/java/com/android/server/am/LockTaskController.java
+++ b/services/core/java/com/android/server/am/LockTaskController.java
@@ -284,6 +284,16 @@ public class LockTaskController {
         return false;
     }
 
+    /**
+     * @return the root task of the lock task.
+     */
+    TaskRecord getRootTask() {
+        if (mLockTaskModeTasks.isEmpty()) {
+            return null;
+        }
+        return mLockTaskModeTasks.get(0);
+    }
+
     private boolean isLockTaskModeViolationInternal(TaskRecord task, boolean isNewClearTask) {
         // TODO: Double check what's going on here. If the task is already in lock task mode, it's
         // likely whitelisted, so will return false below.
diff --git a/services/core/java/com/android/server/am/RecentTasks.java b/services/core/java/com/android/server/am/RecentTasks.java
index fc8b624f6b7e6..345246856d28a 100644
--- a/services/core/java/com/android/server/am/RecentTasks.java
+++ b/services/core/java/com/android/server/am/RecentTasks.java
@@ -1150,6 +1150,11 @@ class RecentTasks {
                 }
         }
 
+        // If we're in lock task mode, ignore the root task
+        if (task == mService.mLockTaskController.getRootTask()) {
+            return false;
+        }
+
         return true;
     }