How to create a JButton with a menu?
-
18-09-2019 - |
Question
I want to create a Toolbar in my application. If you click a button on that toolbar, it will pop up a menu, just like in Eclipse's toolbar. I don't know how to do this in Swing. Can someone help me please? I've tried Google but found nothing.
Solution
This is way harder in Swing than it needs to be. So instead of pointing you to tutorials I've created a fully working example.
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class ToolbarDemo {
public static void main(String[] args) {
final JFrame frame = new JFrame();
frame.setPreferredSize(new Dimension(600, 400));
final JToolBar toolBar = new JToolBar();
//Create the popup menu.
final JPopupMenu popup = new JPopupMenu();
popup.add(new JMenuItem(new AbstractAction("Option 1") {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(frame, "Option 1 selected");
}
}));
popup.add(new JMenuItem(new AbstractAction("Option 2") {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(frame, "Option 2 selected");
}
}));
final JButton button = new JButton("Options");
button.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
popup.show(e.getComponent(), e.getX(), e.getY());
}
});
toolBar.add(button);
frame.getContentPane().add(toolBar, BorderLayout.NORTH);
frame.pack();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
OTHER TIPS
I don't see why this is harder than it needs to be or why you should use a MouseListener. The solution by Steve McLeod works, but where the menu appears depends on where the mouse was clicked. Why not just use an ActionListener as normally used for a JButton. It seems neither harder nor less hard.
final JPopupMenu menu = new JPopupMenu();
menu.add(...whatever...);
final JButton button = new JButton();
button.setText("My Menu");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ev) {
menu.show(button, button.getBounds().x, button.getBounds().y
+ button.getBounds().height);
}
});
This positions the menu about the same as a menu in a JMenuBar for me, and the position is consistent. You could place it differently by modifying the x and y in menu.show().
I think it's the same as in AWT.
You should put an ActionCommand on that button and when it's executed show the pop-up menu according to the mouse coordinates.
See the section Bringing Up a Popup Menu, in How to Use Menus.
I'm not sure I understand you correctly but if you want to know how to make toolbars in Swing check this
Java Tutorials: How to Use Tool Bars and this
Here is a simple and nice class
import javax.swing.JPopupMenu;
import javax.swing.JToggleButton;
import javax.swing.event.PopupMenuEvent;
import javax.swing.event.PopupMenuListener;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class MenuButton extends JToggleButton {
JPopupMenu popup;
public MenuButton(String name, JPopupMenu menu) {
super(name);
this.popup = menu;
addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ev) {
JToggleButton b = MenuButton.this;
if (b.isSelected()) {
popup.show(b, 0, b.getBounds().height);
} else {
popup.setVisible(false);
}
}
});
popup.addPopupMenuListener(new PopupMenuListener() {
@Override
public void popupMenuWillBecomeVisible(PopupMenuEvent e) {}
@Override
public void popupMenuWillBecomeInvisible(PopupMenuEvent e) {
MenuButton.this.setSelected(false);
}
@Override
public void popupMenuCanceled(PopupMenuEvent e) {}
});
}
}