lwimagebutton.java

it is whiteboard sourse code

package org.merlin.step.nov;

import java.awt.*;
import java.awt.event.*;

public class LWImageButton extends Component {
  String name;
  Image image;
  Dimension size, imSize;
  boolean up, down;
  
  public LWImageButton (String n, Image i, Dimension d) {
    name = n;
    image = i;
    size = d;
    enableEvents (AWTEvent.MOUSE_EVENT_MASK);
    imSize = new Dimension (image.getWidth (this), image.getHeight (this));
  }

  public Dimension getPreferredSize () {
    return getMinimumSize ();
  }

  public Dimension getMinimumSize () {
    return new Dimension (size);
  }

  public void paint (Graphics g) {
    if ((imSize.width == -1) || (imSize.height == -1))
      imSize = new Dimension (image.getWidth (this), image.getHeight (this));
    int off = !up ? 0 : down ? 1 : -1;
    if ((imSize.width != -1) && (imSize.height != -1))
      g.drawImage (image, (getSize ().width - imSize.width) / 2 + off, (getSize ().height - imSize.height) / 2 + off, this);
    g.setColor (Color.gray);
    if (up)
      g.draw3DRect (0, 0, getSize ().width - 1, getSize ().height - 1, !down);
  }

  protected void processMouseEvent (MouseEvent e) {
    super.processMouseEvent (e);
    if (isEnabled ()) {
      if (e.getID () == MouseEvent.MOUSE_ENTERED) {
        if (!up) {
          up = true;
          repaint ();
        }
      } else if (e.getID () == MouseEvent.MOUSE_EXITED) {
        if (up) {
          up = false;
          repaint ();
        }
      } else if (e.getID () == MouseEvent.MOUSE_PRESSED) {
        if (!down) {
          down = true;
          repaint ();
        }
      } else if (e.getID () == MouseEvent.MOUSE_RELEASED) {
        if (down) {
          down = false;
          repaint ();
        }
        if (up)
          fireActionEvent (new ActionEvent (this, ActionEvent.ACTION_PERFORMED, name));
      }
    }
  }
  
  ActionListener listeners;

  public synchronized void addActionListener (ActionListener l) {
    listeners = AWTEventMulticaster.add (listeners, l);
  }

  public synchronized void removeActionListener (ActionListener l) {
    listeners = AWTEventMulticaster.remove (listeners, l);
  }

  public synchronized void fireActionEvent (ActionEvent e) {
    if (listeners != null)
      listeners.actionPerformed (e);
  }
}