* Event handling is delegated to an ButtonLikeListener. * setListener(ButtonLikeListener) may be used to fit an * ImageButton with a different derivation of * ButtonLikeListener after construction.
* * ImageButtons ensure that their Images are completely loaded * before they are displayed.
*
* setEnabled (false) disables response to input and repaints
* the image with a black and white version. setEnabled (true)
* restores the original image and enables response to input.
*
* @version 1.0, Apr 1 1996
* @version 1.1, Nov 8 1996
* @version 1.2, Dec 19 1996
*
* 1.1:.........................................................
* Added default constructor and a constructor taking an Image
* and an int (for thickness).
*
* Added static methods for getting/setting default thickness.
*
* Since an ImageButton is a Canvas,
* it will fire mouse and mouse motion events
* that can be listened to by others.
*
* ImageButton uses a BlackAndWhiteFilter to drain the color out
* of the button when it is disabled.
*
* @author David Geary
* @see ThreeDRectangle
* @see ButtonLikeListener
* @see SpringyButtonLikeListener
* @see StickyButtonLikeListener
* @see BleachImageFilter
* @see gjt.test.ImageButtonTest
*
* Extensive changes to the text book example;
* simplified event handling,
* simplified API
* simplified painting
* accepts either Image or DrawImage
* optional separate pressedImage
* @see DrawImage
*
* additions by Morris Hirsch IPD Inc 1998
*/
public class ImageButton extends Component
implements ButtonLike {
private static BlackAndWhiteFilter _bwFilter;
private boolean Pressed = false;
private boolean Enabled = true;
private Dimension prefSize = new Dimension(0,0);
private int thickness;
private Image
mainImage = null,
disabledImage = null,
pressedImage = null,
pressed_disabledImage = null;
private String text = null;
private DrawImage drawImage = null;
private ButtonLikeListener listener = null;
/* Constructors and param setting methods */
/** Construct an ImageButton.
* @param listener,
* @param image,
* @param thickness,
* @param text
*/
public ImageButton (ButtonLikeListener listener, Image image, int thickness, String text) {
setListener (listener);
setImage (image);
setThickness (thickness);
setText (text);
}
/** Construct an ImageButton,
* using a DrawImage instead of an Image.
* @param listener,
* @param drawImage,
* @param thickness,
* @param text
*/
public ImageButton (ButtonLikeListener listener, DrawImage drawImage, int thickness, String text) {
setListener (listener);
setDrawImage (drawImage);
setThickness (thickness);
setText (text);
}
/** Set 3D edge thickness.
* @param thickness,
*/
public void setThickness(int thickness) {
if (thickness < 0)
thickness = 0;
this.thickness = thickness;
if (isShowing ()) {
invalidate ();
getParent ().validate();
}
}
public void setText (String text) {
this.text = text;
}
public String getText () {
return text;
}
/** Set the main Image */
public void setImage (Image mainImage) {
this.mainImage = mainImage;
if (isShowing ()) {
invalidate ();
getParent ().validate();
}
}
/* Set a distinct Pressed / Inset Image.
* Must be same width and height as mainImage. */
public void setPressedImage (Image pressedImage) {
this.pressedImage = pressedImage;
}
/* Set a drawing to use instead of fixed Image */
public void setDrawImage (DrawImage drawImage) {
this.drawImage = drawImage;
drawImage.setButton (this);
}
/** Set the Listener to provide some button behavior.
* It will listen for both kinds of Mouse events,
* so register it as both kinds of listener. */
public void setListener (ButtonLikeListener ibl) {
if (listener != null) {
removeMouseListener(listener);
removeMouseMotionListener(listener);
}
listener = ibl;
addMouseListener(listener);
addMouseMotionListener(listener);
}
/** Get the current Listener. */
public ButtonLikeListener getListener () {
return listener;
}
/* Sizing methods */
/** * @deprecated as of JDK1.1 */
public Dimension minimumSize () {
return getMinimumSize ();
}
public Dimension getMinimumSize () {
return getPreferredSize ();
}
/** * @deprecated as of JDK1.1 */
public Dimension preferredSize () {
return getPreferredSize ();
}
public Dimension getPreferredSize () {
if (null != drawImage) {
prefSize.width = drawImage.getWidth ();
prefSize.height = drawImage.getHeight ();
}
else {
if (null == mainImage) {
//throw new IllegalStateException ("null image");
prefSize.width = 32;
prefSize.height = 32;
}
else {
Util.waitForImage(this, mainImage);
prefSize.width = mainImage.getWidth (this);
prefSize.height = mainImage.getHeight(this);
}
}
prefSize.width += (2*thickness);
prefSize.height += (2*thickness);
return prefSize;
}
/** * @deprecated as of JDK1.1 */
public void resize(int w, int h) {
setBounds(getLocation ().x, getLocation().y, w, h);
}
public void setSize(int w, int h) {
resize(w,h);
}
/** * @deprecated as of JDK1.1 */
public void reshape(int x, int y, int w, int h) {
// compiler will issue deprecation warning,
// but we can't call super.setBounds ()
super.reshape(x,y,w,h);
}
public void setBounds(int x, int y, int w, int h) {
reshape(x,y,w,h);
}
/** Set appearance Pressed or not */
public void setPressed (boolean Pressed) {
if (this.Pressed == Pressed)
return;
this.Pressed = Pressed;
if (isShowing ()) repaint();
}
public boolean isPressed () {
return Pressed;
}
/* Enable / Disable methods */
public void setEnabled (boolean enable) {
if (Enabled == enable)
return;
Enabled = enable;
if (isShowing ())
repaint();
}
public boolean isEnabled () {
return Enabled;
}
/** * @deprecated as of JDK1.1 */
public void enable () {
setEnabled (true);
}
/** * @deprecated as of JDK1.1 */
public void disable () {
setEnabled (false);
}
/* Paint */
public void paint (Graphics g) {
/* offset to center PS within larger S */
Dimension PS = getPreferredSize ();
Dimension S = getSize ();
Point upperLeft = new Point
((S.width - PS.width) /2,
(S.height - PS.height) /2);
int ulx = upperLeft.x,
uly = upperLeft.y;
/* This should take another arg for Pressed... */
if (null != drawImage)
drawImage.draw (g,
ulx + thickness,
uly + thickness,
Enabled);
else {
if (null == mainImage)
throw new IllegalStateException ("null image");
Image pImage;
if (Enabled) {
if ((null != pressedImage) && Pressed)
pImage = pressedImage;
else
pImage = mainImage;
}
else {
if (null == disabledImage)
disabledImage
= createDisabledImage (mainImage);
if (null == pressed_disabledImage)
pressed_disabledImage
= createDisabledImage (pressedImage);
if ((null != pressed_disabledImage) && Pressed)
pImage = pressed_disabledImage;
else
pImage = disabledImage;
}
g.drawImage (pImage,
ulx + thickness,
uly + thickness,
this);
}
/* Not Pressed --
* Top and Left edges brighter than BG,
* Bottom and Right edges darker than BG
*
* Pressed --
* Top and Left edges darker than BG,
* Bottom and Right edges brighter than BG */
Util.paint3DRect (g, getBackground (),
ulx, uly, PS.width, PS.height,
thickness, false,
!Pressed);
}
private Image createDisabledImage (Image fromImage) {
Image grayImage;
if (null == fromImage)
return null;
Util.waitForImage (this, fromImage);
if (_bwFilter == null)
_bwFilter = new BlackAndWhiteFilter ();
FilteredImageSource fis =
new FilteredImageSource (fromImage.getSource (),
_bwFilter);
Util.waitForImage (this, grayImage = createImage (fis));
return grayImage;
}
/** Extensions should override one or both of these, */
public void processStateChange (boolean s) { }
public void processAction () { }
}
/* */