java检测何时创建或关闭任何窗口

Question

是否可以在应用程序中的任何窗口创建或关闭时得到通知？

目前我正在进行民意调查,Window.getWindows()但我更愿意收到通知.

是)我有的:

List<Window> previousWindows = new ArrayList<>();
while (true) {
    List<Window> currentWindows = Arrays.asList(Window.getWindows());

    for (Window window : currentWindows) {
        if (!previousWindows.contains(window)) {
            //window was created
        }
    }

    for (Window window : previousWindows) {
        if (!currentWindows.contains(window)) {
            //window was closed
        }
    }

    previousWindows = currentWindows;
    Thread.sleep(1000);
}

我想要的是什么:

jvm.addWindowListener(this);

@Override
public void windowWasDisplayed(Window w) {
    //window was created
}

@Override
public void windowWasClosed(Window w) {
    //window was closed
}

Answer 1

您可以通过窗口注册接收任何类型的AWT事件子集的侦听器Toolkit.从那些你可以选择和处理WindowEvent窗口打开和关闭,如下所示:

class WindowMonitor implements AWTEventListener {
    public void eventDispatched(AWTEvent event) {
        switch (event.getID()){
            case WindowEvent.WINDOW_OPENED:
                doSomething();
                break;
            case WindowEvent.WINDOW_CLOSED:
                doSomethingElse();
                break;
        }
    }

    // ...
}

class MyClass {

    // alternative 1
    public void registerListener() {
        Toolkit.getDefaultToolkit().addAWTEventListener(new WindowMonitor(),
                AWTEvent.WINDOW_EVENT_MASK);
    }

    // alternative 2
    public void registerListener(Component component) {
        component.getToolkit().addAWTEventListener(new WindowMonitor(),
                AWTEvent.WINDOW_EVENT_MASK);
    }
}

我建议使用替代方案2,其中Component您获得的Toolkit是您应用程序的主框架(应该只有一个),但如果您必须在不参考任何特定组件的情况下执行此操作,则替代方案1应该适合您(对于实例,在创建之前).

但请注意,注册AWTEventListener是否需要进行安全检查.