Move the 'next launch target' logic into the task stack

For better reusability in other flavors of Recents.

Bug: 32101881
Test: Behavior is covered by existing automated tests.
Change-Id: Ibe39cbae0b5973210cad478a9c5ab75280ee0ac2

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 745f5a5..178cb9f 100644 (file)
--- a/packages/SystemUI/src/com/android/systemui/recents/model/TaskStack.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/model/TaskStack.java
@@ -849,6 +849,24 @@ public class TaskStack {
         return null;
     }
 
+    /**
+     * Returns the task in stack tasks which should be launched next if Recents are toggled
+     * again, or null if there is no task to be launched.
+     */
+    public Task getNextLaunchTarget() {
+        int taskCount = getTaskCount();
+        if (taskCount == 0) {
+            return null;
+        }
+        int launchTaskIndex = indexOfStackTask(getLaunchTarget());
+        if (launchTaskIndex != -1) {
+            launchTaskIndex = Math.max(0, launchTaskIndex - 1);
+        } else {
+            launchTaskIndex = getTaskCount() - 1;
+        }
+        return getStackTasks().get(launchTaskIndex);
+    }
+
     /** Returns the index of this task in this current task stack */
     public int indexOfStackTask(Task t) {
         return mStackTaskList.indexOf(t);

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 77c61f8..8c94c35 100644 (file)
--- a/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/views/TaskStackView.java
@@ -1683,17 +1683,11 @@ public class TaskStackView extends FrameLayout implements TaskStack.TaskStackCal
             return;
         }
 
-        int launchTaskIndex = mStack.indexOfStackTask(mStack.getLaunchTarget());
-        if (launchTaskIndex != -1) {
-            launchTaskIndex = Math.max(0, launchTaskIndex - 1);
-        } else {
-            launchTaskIndex = mStack.getTaskCount() - 1;
-        }
-        if (launchTaskIndex != -1) {
+        final Task launchTask = mStack.getNextLaunchTarget();
+        if (launchTask != null) {
             // Stop all animations
             cancelAllTaskViewAnimations();
 
-            final Task launchTask = mStack.getStackTasks().get(launchTaskIndex);
             float curScroll = mStackScroller.getStackScroll();
             float targetScroll = mLayoutAlgorithm.getStackScrollForTaskAtInitialOffset(launchTask);
             float absScrollDiff = Math.abs(targetScroll - curScroll);