Add funtional animation for SplitSelect from Grid.

Long ways to go to final UI - TODO(b/186800707)
Add comments to grid layout code,
no functional changes at all.

Bug: 181705607
Test: Enter split screen from overview task menu
in grid and carousel. Able to select all items
and enter split.

Change-Id: Ib62f1b286acf0781ec47862fa31b670e6ff1892a

quickstep/src/com/android/quickstep/util/SplitSelectStateController.java

@@ -25,6 +25,7 @@ import static com.android.launcher3.util.SplitConfigurationOptions.STAGE_POSITIO
 import android.animation.AnimatorSet;
 import android.app.ActivityOptions;
 import android.content.res.Resources;
+import android.graphics.Rect;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
@@ -64,6 +65,7 @@ public class SplitSelectStateController {
     private final SystemUiProxy mSystemUiProxy;
     private TaskView mInitialTaskView;
     private SplitPositionOption mInitialPosition;
+    private Rect mInitialBounds;
     private final Handler mHandler;
 
     public SplitSelectStateController(Handler handler, SystemUiProxy systemUiProxy) {
@@ -74,9 +76,11 @@ public class SplitSelectStateController {
     /**
      * To be called after first task selected
      */
-    public void setInitialTaskSelect(TaskView taskView, SplitPositionOption positionOption) {
+    public void setInitialTaskSelect(TaskView taskView, SplitPositionOption positionOption,
+            Rect initialBounds) {
         mInitialTaskView = taskView;
         mInitialPosition = positionOption;
+        mInitialBounds = initialBounds;
     }
 
     /**
@@ -220,9 +224,14 @@ public class SplitSelectStateController {
     public void resetState() {
         mInitialTaskView = null;
         mInitialPosition = null;
+        mInitialBounds = null;
     }
 
     public boolean isSplitSelectActive() {
         return mInitialTaskView != null;
     }
+
+    public Rect getInitialBounds() {
+        return mInitialBounds;
+    }
 }