Fixes for touch exclusion region

- Evaluate touch exclusion region on per-task basis, instead of per
  window. Smallest unit for exclusion is Task, if task has more than
  one app window, we still need to use the visible area of the task
  to do focus transfer properly.

- Only add back the touch region for focused task after all tasks
  are processed for eclusion, otherwise the focused area could be
  removed from exclusion incorrectly.

- Skip app windows that's exiting or hidden.

bug: 25494928

Change-Id: I972ba2149431557e7420b1095d9496a6cd821bdb
diff --git a/services/core/java/com/android/server/wm/TaskPositioner.java b/services/core/java/com/android/server/wm/TaskPositioner.java
index dd47e7a..f5e4e3b 100644
--- a/services/core/java/com/android/server/wm/TaskPositioner.java
+++ b/services/core/java/com/android/server/wm/TaskPositioner.java
@@ -332,30 +332,34 @@
                 + ", {" + startX + ", " + startY + "}");
         }
         mCtrlType = CTRL_NONE;
+        mTask = win.getTask();
+        mStartDragX = startX;
+        mStartDragY = startY;
+
+        // Use the dim bounds, not the original task bounds. The cursor
+        // movement should be calculated relative to the visible bounds.
+        // Also, use the dim bounds of the task which accounts for
+        // multiple app windows. Don't use any bounds from win itself as it
+        // may not be the same size as the task.
+        mTask.getDimBounds(mTmpRect);
+
         if (resize) {
-            final Rect visibleFrame = win.mVisibleFrame;
-            if (startX < visibleFrame.left) {
+            if (startX < mTmpRect.left) {
                 mCtrlType |= CTRL_LEFT;
             }
-            if (startX > visibleFrame.right) {
+            if (startX > mTmpRect.right) {
                 mCtrlType |= CTRL_RIGHT;
             }
-            if (startY < visibleFrame.top) {
+            if (startY < mTmpRect.top) {
                 mCtrlType |= CTRL_TOP;
             }
-            if (startY > visibleFrame.bottom) {
+            if (startY > mTmpRect.bottom) {
                 mCtrlType |= CTRL_BOTTOM;
             }
             mResizing = true;
         }
 
-        mTask = win.getTask();
-        mStartDragX = startX;
-        mStartDragY = startY;
-
-        // Use the visible bounds, not the original task bounds. The cursor
-        // movement should be calculated relative to the visible bounds.
-        mWindowOriginalBounds.set(win.mVisibleFrame);
+        mWindowOriginalBounds.set(mTmpRect);
     }
 
     private void endDragLocked() {