In this example we are going to see how to use InternalFrameListener in Java. When you are developing an application with a vivid Graphical environment it is very possible that you will use JInternalFrame components to enhance the end user’s experience. As you might image the monitoring an handling of the several events that occur in the life cycle of the internal frame is very important in this case.
In short, to use an InternalFrameListener, one should follow these steps:
- Create a new
InternalFrameListener. - Override the methods that correspond to the events that you want to monitor in the frame e.g
internalFrameActivated,internalFrameClosed,internalFrameClosing,internalFrameDeactivated,internalFrameDeiconified,internalFrameIconified,internalFrameOpenedand customize as you wish the handling of the respective events. Now every time an event occurs in the frame, the corresponding method will be executed. - Create a new
JInternalFramecomponent and use theaddInternalFrameListenerto add theInternalFrameListeneryou’ve created.
Let’s take a closer look at the code snippet that follows:
package com.javacodegeeks.snippets.desktop;
import java.awt.BorderLayout;
import java.awt.Container;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JLayeredPane;
import javax.swing.event.InternalFrameEvent;
import javax.swing.event.InternalFrameListener;
public class InternalFrameListenerExample {
public static void main(String args[]) {
JFrame jFrame = new JFrame();
Container cPane = jFrame.getContentPane();
JLayeredPane layerPane = new JDesktopPane();
layerPane.setOpaque(false);
layerPane.add(createLayer("First"), JLayeredPane.POPUP_LAYER);
layerPane.add(createLayer("Seond"), JLayeredPane.DEFAULT_LAYER);
layerPane.add(createLayer("Third"), JLayeredPane.PALETTE_LAYER);
cPane.add(layerPane, BorderLayout.CENTER);
jFrame.setSize(800, 600);
jFrame.setVisible(true);
}
static JInternalFrame createLayer(String label) {
return new InternalFrame(label);
}
static class InternalFrame extends JInternalFrame {
InternalFrameListener listener = new InternalFrameListener() {
@Override
public void internalFrameActivated(InternalFrameEvent event) {
printInfoOfEvent("Activated", event);
}
@Override
public void internalFrameClosed(InternalFrameEvent event) {
printInfoOfEvent("Closed", event);
}
@Override
public void internalFrameClosing(InternalFrameEvent event) {
printInfoOfEvent("Closing", event);
}
@Override
public void internalFrameDeactivated(InternalFrameEvent event) {
printInfoOfEvent("Deactivated", event);
}
@Override
public void internalFrameDeiconified(InternalFrameEvent event) {
printInfoOfEvent("Deiconified", event);
}
@Override
public void internalFrameIconified(InternalFrameEvent event) {
printInfoOfEvent("Iconified", event);
}
@Override
public void internalFrameOpened(InternalFrameEvent event) {
printInfoOfEvent("Opened", event);
}
private void printInfoOfEvent(String str, InternalFrameEvent event) {
System.out.println("Source: " + event.getInternalFrame().getName()
+ " : " + str);
}
};
public InternalFrame(String str) {
getContentPane().add(new JLabel(str, JLabel.CENTER),BorderLayout.CENTER);
setName(str);
addInternalFrameListener(listener);
setBounds(100, 100, 100, 100);
setResizable(true);
setClosable(true);
setMaximizable(true);
setIconifiable(true);
setTitle(str);
setVisible(true);
}
}
}
This was an example on how to use InternalFrameListener in Java.
