使复合小部件可拖动的问题答案

【问题标题】：Issue in making composite widget draggable使复合小部件可拖动的问题
【发布时间】：2009-12-28 06:20:10
【问题描述】：

我对 gwt n dnd 比较陌生.. 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，它会引发异常 “dragHandle 必须实现 HasMouseDownHandlers、HasMouseUpHandlers、HasMouseMoveHandlers 和 HasMouseOutHandlers 才能拖动”我是否遗漏了一些非常重要的东西？

谢谢，信德

【问题讨论】：

标签： gwt drag-and-drop

【解决方案1】：

你可以这样实现它们：

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 http://groups.google.com/group/gwt-dnd/browse_thread/thread/85039aaa229d53cf/f5ad10ff9a37ab9d?lnk=gst&q=custom+widget#f5ad10ff9a37ab9d

【讨论】：