java - JFrame.HIDE_ON_CLOSE onHide 事件？

Question

我有一个WorldEditor启动 JFrame 的GameJFrame。但是，当Game关闭时，我不希望它结束​​整个程序，所以我将默认关闭操作设置为HIDE_ON_CLOSE. 但是，为了节省资源，我WorldEditor会在Game运行时暂停。

如何检测Game窗口何时隐藏以便恢复WorldEditor？

Answer 1

Why don't you hide the frame yourself instead of using a default HIDE_ON_CLOSE?

// inside WindowListener class
public windowClosing(WindowEvent e) {
    yourFrame.setVisible( false );
    // your code here...
}

Edit made: from docs:

The default close operation is executed after any window listeners handle the window-closing event. So, for example, assume that you specify that the default close operation is to dispose of a frame. You also implement a window listener that tests whether the frame is the last one visible and, if so, saves some data and exits the application. Under these conditions, when the user closes a frame, the window listener will be called first. If it does not exit the application, then the default close operation — disposing of the frame — will then be performed.

New edit with a working example:

import java.awt.event.*;
import javax.swing.JFrame;

public class ListenerTest extends JFrame implements WindowListener {

public static void main(String[] args) {
    ListenerTest frame = new ListenerTest();
    frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
    frame.setVisible( true );
}

public ListenerTest() {
    this.addWindowListener( this );
}

public void windowActivated(WindowEvent e) {
    System.out.println(" activated ");
}
public void windowClosed(WindowEvent e){
    System.out.println(" closed ");
}
public void windowClosing(WindowEvent e){
    System.out.println(" closing ");
}
public void windowDeactivated(WindowEvent e){
    System.out.println(" deactivated ");
}
public void windowDeiconified(WindowEvent e){
    System.out.println(" deiconified ");
}
public void windowIconified(WindowEvent e){
    System.out.println(" iconified ");
}
public void windowOpened(WindowEvent e){
    System.out.println(" opened ");
}
}

Test this out in order to catch what which events are firing.