要将元素转换为FlowPanel吗？

Question

我正在尝试创建我自己的复合按钮，使用div作为外部父按钮：

public class CompoundButton extends ButtonBase {
    public CompoundButton() {
        super(DOM.createDiv());
    }
}

不过，ButtonBase的构造函数需要一个Element实例，所以我使用DOM.createDiv()调用。但是现在如何添加子小部件呢？：

public CompoundButton() {
    super(DOM.createDiv());  <-- we're just a div.

    // ButtonBase has no "add()" method - but this class is really 
    // just a div instance, so shouldn't I be able to convert it to 
    // a FlowPanel for example to be able to add elements to it here?
    this.add(new FlowPanel());   <-- not possible, "add()" not available here.

谢谢

Answer 1

Button base接受一个单元格，而flowpanel不是一个单元格，您的复合按钮代码是错误的，因为它不会将单元格发送给它的父级。

正确的代码是

public class CompoundButton<C> extends ButtonBase<C>
{
   protected CompoundButton( ButtonCellBase<C> cell )
   {
        super( cell );
   }
}