我正在处理的应用程序包含一个主 JFrame,用户最终可能会从中打开另一个补充框架。我正在尝试实现应用程序的这种行为,其中一旦主框架最小化,补充框架就会最小化(图标化)。
我正在考虑覆盖主框架的 setExtendedState 方法以捕获它被最小化的时刻,然后从那里触发属性更改事件,以便补充框架可以对其进行操作。
然而,我发现,不幸的是,被覆盖的 setExtendedState 永远不会被调用。
我将不胜感激任何实现所需行为的想法。以下是我用于测试的代码...
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
public class IconifySupplementaryFrameTest {
public static void main(String[] args) {
(new MainFrame()).setVisible(true);
}
}
class MainFrame extends JFrame {
public static final String EXTENDED_STATE_KEY = "extendedState";
MainFrame() {
super("Iconify test - main window");
setLayout(new FlowLayout(FlowLayout.LEADING));
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(400, 400);
setLocationByPlatform(true);
add(new JButton(new AbstractAction("Show supplementary frame") {
@Override
public void actionPerformed(ActionEvent e) {
SupplementaryFrame.doShow(MainFrame.this);
}
}));
}
@Override
public synchronized void setExtendedState(int state) {
// This overridden method is never called ???
int oldState = getExtendedState();
super.setExtendedState(state);
firePropertyChange(EXTENDED_STATE_KEY, oldState, state);
}
}
class SupplementaryFrame extends JFrame implements PropertyChangeListener {
private static SupplementaryFrame instance;
private SupplementaryFrame(final JFrame parentFrame) {
super("Iconify test - supplementary window");
setSize(300, 300);
setLocationRelativeTo(parentFrame);
parentFrame.addPropertyChangeListener(
MainFrame.EXTENDED_STATE_KEY, this);
addWindowListener(new WindowAdapter() {
@Override
public void windowClosing(WindowEvent e) {
instance = null;
parentFrame.removePropertyChangeListener(
MainFrame.EXTENDED_STATE_KEY,
SupplementaryFrame.this);
SupplementaryFrame.this.dispose();
}
});
}
static void doShow(JFrame parentFrame) {
if(instance == null) {
instance = new SupplementaryFrame(parentFrame);
instance.setVisible(true);
}
else {
// omitted _ugly_ code to bring this window (instance) to front
}
}
@Override
public void propertyChange(PropertyChangeEvent evt) {
int state = this.getExtendedState();
int parentState = ((Integer)evt.getNewValue()).intValue();
if((parentState & ICONIFIED) == ICONIFIED)
this.setExtendedState(state | ICONIFIED);
}
}