将事件传递给父母 [英] Passing events to parent

问题描述

我想创建一个应用程序，其中一些事件应该被处理，就像它们被传递到父容器一样。例如，我有一个包含JLabel的JPanel。顶级的JPanel现在实现了鼠标和拖动。为了使事件看起来像他们到达JPanel而不是标签本身，我需要做些什么。 （更改源对象很重要）

I'd like to create an app where some events are supposed to be handled as if they were delivered to parent containers. For example I've got a JPanel which contains JLabel. The top JPanel implements mousepress and dragging right now. What do I need to do, in order to make the events look like they arrived to JPanel instead of the label itself. (changing source object is important)

有没有比实际实现事件更好的解决方案，并在父代中复制它们？ （在一些具有> 5个孩子的对象之后，这将变得乏味）。

Is there some better solution than actually implementing the events and replicating them in the parent? (this would get tedious after some objects with >5 children).

推荐答案

在事件侦听器中，您可以将事件发送到父组件。

At your event listener, you can dispatch the event to the parent component.

正在 myEvent 事件处理函数参数：

Being myEvent the event handling function argument:

Component source=(Component)myEvent.getSource();
source.getParent().dispatchEvent(myEvent);

但是这个解决方案意味着为要添加的每个元素创建一个新的EventListener。

But this solution implies creating a new EventListener for each element to add.

所以，你可以创建一个单独的事件处理程序并重新使用它，将其添加到所有选定的子项，如下所示：

So, you could create a single event handler and reuse it, adding it to all the chosen children, like this:

final Container parent=this; //we are a the parent container creation code
MouseListener myCommonListener=new MouseListener() {
    @Override
    public void mouseClicked(MouseEvent e) {
        parent.dispatchEvent(e);
    }
    @Override
    public void mouseEntered(MouseEvent e) {
        parent.dispatchEvent(e);
    }
    @Override
    public void mouseExited(MouseEvent e) {
        parent.dispatchEvent(e);
    }
    @Override
    public void mousePressed(MouseEvent e) {
        parent.dispatchEvent(e);
    }
    @Override
    public void mouseReleased(MouseEvent e) {
        parent.dispatchEvent(e);
    }
};

JLabel label=new JLabel("This is the first Label");
label.addMouseListener(myCommonListener);

JLabel label2=new JLabel("This is the second Label");
label2.addMouseListener(myCommonListener);
//... and so on 

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