Drop Down Menu Buttons

[Jeff Storey]

Hi. I'm looking for a way that I can create a menu button that has an optional drop-down arrow. Clicking the button switches the mode of my application to a "drawing" mode, where you can draw several different types of lines. If they just click the button, it should use the default drawing tool, but if they click the drop-down arrow they should see a list of available drawing tools (this is similar to MS Outlook where you can click the "New" button to create a new mail message or click the drop-down arrow to see what new items you can create). The key is that this needs to be a single button object such that mouse-overing, borders, etc don't make it appear as multiple buttons.

Thank you.
Jeff

[Michael Dunn]

it should be just a matter of adding a thin BasicArrowButton alongside
a normal button, with the BasicArrowButton displaying a popup, as in a JComboBox

[Jeff Storey]

The problem with doing it that way is that I lose the mouse over effect. I can mouse over the button and combo box as two separate components, where I'm trying to treat them as a single component for mousing over purposes.

[Craig Wood]

import java.awt.*;
import java.awt.event.*;
import java.awt.font.*;
import java.awt.geom.*;
import javax.swing.*;
 
public class OptionComponent extends JPanel {
    String text;
    GeneralPath arrow;
    int left;
    boolean firstTime = true;
    boolean isSelected = false;
 
    OptionComponent(String text) {
        this.text = text;
        setBackground(UIManager.getColor("Menu.background"));
        setForeground(UIManager.getColor("Menu.foreground"));
        setOpaque(false);
        addMouseListener(ml);
    }
 
    protected void paintComponent(Graphics g) {
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int h = getHeight();
        Font font = UIManager.getFont("Menu.font");
        g2.setFont(font);
        FontRenderContext frc = g2.getFontRenderContext();
        Rectangle2D r = font.getStringBounds(text, frc);
        float sx = 5f;
        float sy = (float)((h + r.getHeight())/2) -
                       font.getLineMetrics(text, frc).getDescent();
        g2.drawString(text, sx, sy);
        double x = sx + r.getWidth() + sx;
        if(isSelected) {
            g2.setPaint(Color.gray);
            g2.draw(new Line2D.Double(x, 0, x, h));
            g2.setPaint(Color.white);
            g2.draw(new Line2D.Double(x+1, 0, x+1, h));
            g2.setPaint(Color.gray);
            g2.draw(new Rectangle2D.Double(0, 0, getSize().width-1, h-1));
        }
        float ax = (float)(x + sx);
        if(firstTime)
            createArrow(ax, h);
        g2.setPaint(UIManager.getColor("Menu.foreground"));
        g2.fill(arrow);
        ax += 10f + sx;
        if(firstTime) {
            setSize((int)ax, h);         // initial sizing
            setPreferredSize(getSize());
            setMaximumSize(getSize());   // resizing behavior
            left = (int)x + 1;           // for mouse listener
            firstTime = false;
        }
    }
 
    private void createArrow(float x, int h) {
        arrow = new GeneralPath();
        arrow.moveTo(x, h/3f);
        arrow.lineTo(x + 10f, h/3f);
        arrow.lineTo(x + 5f, h*2/3f);
        arrow.closePath();
    }
 
    private JMenuBar getMenuBar() {
        JMenu menu = new JMenu("menu");
        JMenuItem item = new JMenuItem("menu item");
        menu.add(item);
        JMenuBar menuBar = new JMenuBar();
        menuBar.add(menu);
        menuBar.add(this);
        return menuBar;
    }
 
    public static void main(String[] args) {
        OptionComponent test = new OptionComponent("draw");
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setJMenuBar(test.getMenuBar());
        f.getContentPane();
        f.setSize(200,100);
        f.setLocation(200,200);
        f.setVisible(true);
    }
 
    private MouseListener ml = new MouseAdapter() {
        JPopupMenu popupMenu = getPopupMenu();
 
        public void mousePressed(MouseEvent e) {
            if(e.getX() <= left)
                System.out.println("Use default drawing tool.");
            else
                popupMenu.show(OptionComponent.this, 0, getHeight());
        }
 
        public void mouseEntered(MouseEvent e) {
            isSelected = true;
            repaint();
        }
 
        public void mouseExited(MouseEvent e) {
            isSelected = false;
            repaint();
        }
    };
 
    private JPopupMenu getPopupMenu() {
        JPopupMenu popupMenu = new JPopupMenu();
        String[] ids = { "pencil", "brush", "fill" };
        for(int j = 0; j < ids.length; j++) {
            JMenuItem item = new JMenuItem(ids[j]);
            popupMenu.add(item);
        }
        return popupMenu;
    }
}

[Jeff Storey]

Thanks. Can I ask if you wrote this code or if it is copyrighted or where you got it from?

[Craig Wood]

Can I ask if you wrote this code
Yes, I wrote it.
or if it is copyrighted
No, not that I know of.
or where you got it from?
I made it up after reading your original post today.
You can do whatever you like with it.