gwt - 使复合小部件可拖动时出现问题

Question

对 gwt n dnd 来说相对很新。我创建了一个复合小部件。当我尝试使复合小部件的对象可拖动时，它会抛出异常 “dragHandle 必须实现 HasMouseDownHandlers、HasMouseUpHandlers、HasMouseMoveHandlers 和 HasMouseOutHandlers 才能可拖动”我是否遗漏了一些非常重要的东西？

谢谢， 辛杜

Answer 1

您可以像这样实现它们:

public class MyWidget extends Composite implements HasAllMouseHandlers, HasClickHandlers {

...

      public HandlerRegistration addClickHandler(ClickHandler handler) {
        return addDomHandler(handler, ClickEvent.getType());
      }

      public HandlerRegistration addMouseDownHandler(MouseDownHandler handler) {
          return addDomHandler(handler, MouseDownEvent.getType());
      }

      public HandlerRegistration addMouseMoveHandler(MouseMoveHandler handler) {
        return addDomHandler(handler, MouseMoveEvent.getType());
      }

      public HandlerRegistration addMouseOutHandler(MouseOutHandler handler) {
        return addDomHandler(handler, MouseOutEvent.getType());
      }

      public HandlerRegistration addMouseOverHandler(MouseOverHandler handler) {
        return addDomHandler(handler, MouseOverEvent.getType());
      }

      public HandlerRegistration addMouseUpHandler(MouseUpHandler handler) {
        return addDomHandler(handler, MouseUpEvent.getType());
      }

      public HandlerRegistration addMouseWheelHandler(MouseWheelHandler handler) {
        return addDomHandler(handler, MouseWheelEvent.getType());
      }

}

要让您的小部件正常工作，请参阅此内容 http://groups.google.com/group/gwt-dnd/browse_thread/thread/85039aaa229d53cf/f5ad10ff9a37ab9d?lnk=gst&q=custom+widget#f5ad10ff9a37ab9d