Elide undelivered drag-location messages
The recipient app could be receiving drag location updates faster than
it handled them, leading to progressive poor responsiveness. Now we
discard any undelivered pending location updates and replace them with
the newest data point when the location is updated.
Change-Id: I7299d205a0ef8ef8f5f32fd14e9ef87383d92717
diff --git a/core/java/android/view/ViewRoot.java b/core/java/android/view/ViewRoot.java
index 14a049c..9993c10 100644
--- a/core/java/android/view/ViewRoot.java
+++ b/core/java/android/view/ViewRoot.java
@@ -1692,6 +1692,7 @@
public final static int CHECK_FOCUS = 1013;
public final static int CLOSE_SYSTEM_DIALOGS = 1014;
public final static int DISPATCH_DRAG_EVENT = 1015;
+ public final static int DISPATCH_DRAG_LOCATION_EVENT = 1016;
@Override
public void handleMessage(Message msg) {
@@ -1867,7 +1868,8 @@
mView.onCloseSystemDialogs((String)msg.obj);
}
} break;
- case DISPATCH_DRAG_EVENT: {
+ case DISPATCH_DRAG_EVENT:
+ case DISPATCH_DRAG_LOCATION_EVENT: {
handleDragEvent((DragEvent)msg.obj);
} break;
}
@@ -2841,7 +2843,14 @@
}
public void dispatchDragEvent(DragEvent event) {
- Message msg = obtainMessage(DISPATCH_DRAG_EVENT, event);
+ final int what;
+ if (event.getAction() == DragEvent.ACTION_DRAG_LOCATION) {
+ what = DISPATCH_DRAG_LOCATION_EVENT;
+ removeMessages(what);
+ } else {
+ what = DISPATCH_DRAG_EVENT;
+ }
+ Message msg = obtainMessage(what, event);
sendMessage(msg);
}