StretchIcon.java

/**
 * @(#)StretchIcon.java	1.0 03/27/12
 */
 

import java.awt.Component;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Insets;
import java.awt.image.ImageObserver;
import java.net.URL;
import javax.swing.ImageIcon;

/**
 * An <CODE>Icon</CODE> that scales its image to fill the component area,
 * excluding any border or insets, optionally maintaining the image's aspect
 * ratio by padding and centering the scaled image horizontally or vertically.
 * <P>
 * The class is a drop-in replacement for <CODE>ImageIcon</CODE>, except that
 * the no-argument constructor is not supported.
 * <P>
 * As the size of the Icon is determined by the size of the component in which
 * it is displayed, <CODE>StretchIcon</CODE> must only be used in conjunction
 * with a component and layout that does not depend on the size of the
 * component's Icon.
 * 
 * @version 1.0 03/27/12
 * @author Darryl
 */
public class StretchIcon extends ImageIcon {

    /**
     * Determines whether the aspect ratio of the image is maintained.
     * Set to <code>false</code> to allow th image to distort to fill the component.
     */
    protected boolean proportionate = true;

    /**
     * Creates a <CODE>StretchIcon</CODE> from an array of bytes.
     *
     * @param  imageData an array of pixels in an image format supported by
     *             the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG
     *
     * @see ImageIcon#ImageIcon(byte[])
     */
    public StretchIcon(byte[] imageData) {
        super(imageData);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from an array of bytes with the specified behavior.
     *
     * @param  imageData an array of pixels in an image format supported by
     *             the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(byte[])
     */
    public StretchIcon(byte[] imageData, boolean proportionate) {
        super(imageData);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from an array of bytes.
     *
     * @param  imageData an array of pixels in an image format supported by
     *             the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG
     * @param  description a brief textual description of the image
     *
     * @see ImageIcon#ImageIcon(byte[], java.lang.String)
     */
    public StretchIcon(byte[] imageData, String description) {
        super(imageData, description);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from an array of bytes with the specified behavior.
     *
     * @see ImageIcon#ImageIcon(byte[])
     * @param  imageData an array of pixels in an image format supported by
     *             the AWT Toolkit, such as GIF, JPEG, or (as of 1.3) PNG
     * @param  description a brief textual description of the image
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(byte[], java.lang.String)
     */
    public StretchIcon(byte[] imageData, String description, boolean proportionate) {
        super(imageData, description);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the image.
     *
     * @param image the image
     *
     * @see ImageIcon#ImageIcon(java.awt.Image)
     */
    public StretchIcon(Image image) {
        super(image);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the image with the specified behavior.
     * 
     * @param image the image
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     * 
     * @see ImageIcon#ImageIcon(java.awt.Image) 
     */
    public StretchIcon(Image image, boolean proportionate) {
        super(image);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the image.
     * 
     * @param image the image
     * @param  description a brief textual description of the image
     * 
     * @see ImageIcon#ImageIcon(java.awt.Image, java.lang.String) 
     */
    public StretchIcon(Image image, String description) {
        super(image, description);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the image with the specified behavior.
     *
     * @param image the image
     * @param  description a brief textual description of the image
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(java.awt.Image, java.lang.String)
     */
    public StretchIcon(Image image, String description, boolean proportionate) {
        super(image, description);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified file.
     *
     * @param filename a String specifying a filename or path
     *
     * @see ImageIcon#ImageIcon(java.lang.String)
     */
    public StretchIcon(String filename) {
        super(filename);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified file with the specified behavior.
     * 
     * @param filename a String specifying a filename or path
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(java.lang.String)
     */
    public StretchIcon(String filename, boolean proportionate) {
        super(filename);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified file.
     *
     * @param filename a String specifying a filename or path
     * @param  description a brief textual description of the image
     *
     * @see ImageIcon#ImageIcon(java.lang.String, java.lang.String)
     */
    public StretchIcon(String filename, String description) {
        super(filename, description);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified file with the specified behavior.
     * 
     * @param filename a String specifying a filename or path
     * @param  description a brief textual description of the image
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(java.awt.Image, java.lang.String)
     */
    public StretchIcon(String filename, String description, boolean proportionate) {
        super(filename, description);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified URL.
     *
     * @param location the URL for the image
     *
     * @see ImageIcon#ImageIcon(java.net.URL)
     */
    public StretchIcon(URL location) {
        super(location);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified URL with the specified behavior.
     * 
     * @param location the URL for the image
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(java.net.URL)
     */
    public StretchIcon(URL location, boolean proportionate) {
        super(location);
        this.proportionate = proportionate;
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified URL.
     *
     * @param location the URL for the image
     * @param  description a brief textual description of the image
     *
     * @see ImageIcon#ImageIcon(java.net.URL, java.lang.String)
     */
    public StretchIcon(URL location, String description) {
        super(location, description);
    }

    /**
     * Creates a <CODE>StretchIcon</CODE> from the specified URL with the specified behavior.
     * 
     * @param location the URL for the image
     * @param  description a brief textual description of the image
     * @param proportionate <code>true</code> to retain the image's aspect ratio,
     *        <code>false</code> to allow distortion of the image to fill the
     *        component.
     *
     * @see ImageIcon#ImageIcon(java.net.URL, java.lang.String)
     */
    public StretchIcon(URL location, String description, boolean proportionate) {
        super(location, description);
        this.proportionate = proportionate;
    }

    /**
     * Paints the icon.  The image is reduced or magnified to fit the component to which
     * it is painted.
     * <P>
     * If the proportion has not been specified, or has been specified as <code>true</code>,
     * the aspect ratio of the image will be preserved by padding and centering the image
     * horizontally or vertically.  Otherwise the image may be distorted to fill the
     * component it is painted to.
     * <P>
     * If this icon has no image observer,this method uses the <code>c</code> component
     * as the observer.
     *
     * @param c the component to which the Icon is painted.  This is used as the
     *          observer if this icon has no image observer
     * @param g the graphics context
     * @param x not used.
     * @param y not used.
     *
     * @see ImageIcon#paintIcon(java.awt.Component, java.awt.Graphics, int, int)
     */
    @Override
    public synchronized void paintIcon(Component c, Graphics g, int x, int y) {
        Image image = getImage();
        if (image == null) {
            return;
        }
        Insets insets = ((Container) c).getInsets();
        x = insets.left;
        y = insets.top;

        int w = c.getWidth() - x - insets.right;
        int h = c.getHeight() - y - insets.bottom;

        if (proportionate) {
            int iw = image.getWidth(c);
            int ih = image.getHeight(c);

            if (iw * h < ih * w) {
                iw = (h * iw) / ih;
                x += (w - iw) / 2;
                w = iw;
            } else {
                ih = (w * ih) / iw;
                y += (h - ih) / 2;
                h = ih;
            }
        }

        ImageObserver io = getImageObserver();
        g.drawImage(image, x, y, w, h, io == null ? c : io);
    }

    /**
     * Overridden to return 0.  The size of this Icon is determined by
     * the size of the component.
     * 
     * @return 0
     */
    @Override
    public int getIconWidth() {
        return 0;
    }

    /**
     * Overridden to return 0.  The size of this Icon is determined by
     * the size of the component.
     *
     * @return 0
     */
    @Override
    public int getIconHeight() {
        return 0;
    }
}