Fixing crash with retrieving the first stack task.

- We should be retrieving the first stack task for calculating the 
  thumbnail transition, regardless of whether it is freeform or not.

Bug: 26739531
Change-Id: I27037a480201396011d7f9b8d094b4d9afe66f0e

3 files changed, 10 insertions, 9 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java b/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
index 3eee08766c73..f8cbf656dfa0 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/RecentsImpl.java
@@ -651,7 +651,7 @@ public class RecentsImpl extends IRecentsNonSystemUserCallbacks.Stub implements
         mDummyStackView.updateLayoutForStack(stack);
         final Task toTask = new Task();
         final TaskViewTransform toTransform = getThumbnailTransitionTransform(stack, stackView,
-                topTask.id, toTask);
+                toTask);
         ForegroundThread.getHandler().postAtFrontOfQueue(new Runnable() {
             @Override
             public void run() {
@@ -721,7 +721,7 @@ public class RecentsImpl extends IRecentsNonSystemUserCallbacks.Stub implements
             // Update the destination rect
             Task toTask = new Task();
             TaskViewTransform toTransform = getThumbnailTransitionTransform(stack, stackView,
-                    topTask.id, toTask);
+                    toTask);
             RectF toTaskRect = toTransform.rect;
             Bitmap thumbnail = getThumbnailBitmap(topTask, toTask, toTransform);
             if (thumbnail != null) {
@@ -754,14 +754,14 @@ public class RecentsImpl extends IRecentsNonSystemUserCallbacks.Stub implements
      * Returns the transition rect for the given task id.
      */
     private TaskViewTransform getThumbnailTransitionTransform(TaskStack stack,
-            TaskStackView stackView, int runningTaskId, Task runningTaskOut) {
+            TaskStackView stackView, Task runningTaskOut) {
         // Find the running task in the TaskStack
         Task launchTask = stack.getLaunchTarget();
         if (launchTask != null) {
             runningTaskOut.copyFrom(launchTask);
         } else {
             // If no task is specified or we can not find the task just use the front most one
-            launchTask = stack.getStackFrontMostTask();
+            launchTask = stack.getStackFrontMostTask(true /* includeFreeform */);
             runningTaskOut.copyFrom(launchTask);
         }
 
diff --git a/packages/SystemUI/src/com/android/systemui/recents/model/TaskStack.java b/packages/SystemUI/src/com/android/systemui/recents/model/TaskStack.java
index c73273e6f258..de1daa8ea988 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/model/TaskStack.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/model/TaskStack.java
@@ -527,9 +527,9 @@ public class TaskStack {
      */
     public void removeTask(Task t, TaskViewAnimation animation) {
         if (mStackTaskList.contains(t)) {
-            boolean wasFrontMostTask = (getStackFrontMostTask() == t);
+            boolean wasFrontMostTask = (getStackFrontMostTask(false /* includeFreeform */) == t);
             removeTaskImpl(mStackTaskList, t);
-            Task newFrontMostTask = getStackFrontMostTask();
+            Task newFrontMostTask = getStackFrontMostTask(false  /* includeFreeform */);
             if (mCb != null) {
                 // Notify that a task has been removed
                 mCb.onStackTaskRemoved(this, t, wasFrontMostTask, newFrontMostTask, animation);
@@ -616,14 +616,14 @@ public class TaskStack {
     /**
      * Gets the front-most task in the stack.
      */
-    public Task getStackFrontMostTask() {
+    public Task getStackFrontMostTask(boolean includeFreeformTasks) {
         ArrayList<Task> stackTasks = mStackTaskList.getTasks();
         if (stackTasks.isEmpty()) {
             return null;
         }
         for (int i = stackTasks.size() - 1; i >= 0; i--) {
             Task task = stackTasks.get(i);
-            if (!task.isFreeformTask()) {
+            if (!task.isFreeformTask() || includeFreeformTasks) {
                 return task;
             }
         }
diff --git a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
index 809d4eed7a11..de045f46f9f9 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
@@ -1427,7 +1427,8 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
         }
 
         // Restore the action button visibility if it is the front most task view
-        if (mScreenPinningEnabled && tv.getTask() == mStack.getStackFrontMostTask()) {
+        if (mScreenPinningEnabled && tv.getTask() ==
+                mStack.getStackFrontMostTask(false /* includeFreeform */)) {
             tv.showActionButton(false /* fadeIn */, 0 /* fadeInDuration */);
         }
     }