An example of the JPopupMenu in action
/*
Java Swing, 2nd Edition
By Marc Loy, Robert Eckstein, Dave Wood, James Elliott, Brian Cole
ISBN: 0-596-00408-7
Publisher: O'Reilly
*/
// MenuElementExample.java
// An example of the JPopupMenu in action.
//
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JSeparator;
import javax.swing.JSlider;
import javax.swing.MenuElement;
import javax.swing.MenuSelectionManager;
import javax.swing.border.CompoundBorder;
import javax.swing.border.EmptyBorder;
import javax.swing.border.TitledBorder;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;
public class MenuElementExample extends JPanel {
public JPopupMenu popup;
SliderMenuItem slider;
int theValue = 0;
public MenuElementExample() {
popup = new JPopupMenu();
slider = new SliderMenuItem();
popup.add(slider);
popup.add(new JSeparator());
JMenuItem ticks = new JCheckBoxMenuItem("Slider Tick Marks");
ticks.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
slider.setPaintTicks(!slider.getPaintTicks());
}
});
JMenuItem labels = new JCheckBoxMenuItem("Slider Labels");
labels.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
slider.setPaintLabels(!slider.getPaintLabels());
}
});
popup.add(ticks);
popup.add(labels);
popup.addPopupMenuListener(new PopupPrintListener());
addMouseListener(new MousePopupListener());
}
// Inner class to check whether mouse events are the popup trigger
class MousePopupListener extends MouseAdapter {
public void mousePressed(MouseEvent e) {
checkPopup(e);
}
public void mouseClicked(MouseEvent e) {
checkPopup(e);
}
public void mouseReleased(MouseEvent e) {
checkPopup(e);
}
private void checkPopup(MouseEvent e) {
if (e.isPopupTrigger()) {
popup.show(MenuElementExample.this, e.getX(), e.getY());
}
}
}
// Inner class to print information in response to popup events
class PopupPrintListener implements PopupMenuListener {
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {
}
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
theValue = slider.getValue();
System.out.println("The value is now " + theValue);
}
public void popupMenuCanceled(PopupMenuEvent e) {
System.out.println("Popup menu is hidden!");
}
}
public static void main(String s[]) {
JFrame frame = new JFrame("Menu Element Example");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane(new MenuElementExample());
frame.setSize(300, 300);
frame.setVisible(true);
}
// Inner class that defines our special slider menu item
class SliderMenuItem extends JSlider implements MenuElement {
public SliderMenuItem() {
setBorder(new CompoundBorder(new TitledBorder("Control"),
new EmptyBorder(10, 10, 10, 10)));
setMajorTickSpacing(20);
setMinorTickSpacing(10);
}
public void processMouseEvent(MouseEvent e, MenuElement path[],
MenuSelectionManager manager) {
}
public void processKeyEvent(KeyEvent e, MenuElement path[],
MenuSelectionManager manager) {
}
public void menuSelectionChanged(boolean isIncluded) {
}
public MenuElement[] getSubElements() {
return new MenuElement[0];
}
public Component getComponent() {
return this;
}
}
}
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