fix conflict between drag & scroll

Runtime/editor/editor_window.cs

                         -evt.delta.y * this._devicePixelRatio,
                         evt.mousePosition.x * this._devicePixelRatio,
                         evt.mousePosition.y * this._devicePixelRatio,
-                        InputUtils.getMouseButtonKey(evt.button)
+                        InputUtils.getScrollButtonKey()
                     );
                 }
                 else if (evt.type == EventType.DragUpdated) {

Runtime/gestures/binding.cs

 
         void _handlePointerScrollEvent(PointerEvent evt) {
             this.pointerRouter.clearScrollRoute(evt.pointer);
+            if (!this.pointerRouter.acceptScroll()) {
+                return;
+            }
 
             HitTestResult result = new HitTestResult();
             this.hitTest(result, evt.position);

Runtime/gestures/pointer_router.cs

                 this._routeMap.Remove(pointer);
             }
         }
+                
+        public bool acceptScroll() {
+            return this._routeMap.Count == 0;
+        }
 
         public void clearScrollRoute(int pointer) {
             if (this._routeMap.ContainsKey(pointer)) {