path: root/src/com/wordpress/tipsforjava/swing/StretchIcon.java

/**
 * @(#)StretchIcon.java	1.0 03/27/12
 */
package com.wordpress.tipsforjava.swing;

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>.
 * <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 03/22/12
 * @author Darryl
 */
public class StretchIcon extends ImageIcon {

	/**
	 * Determines whether the aspect ratio of the image is maintained. Set to
	 * <code>false</code> to distort the image 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 StretchIcon from the image.
	 * 
	 * @param image
	 *            the image
	 * 
	 * @see ImageIcon#ImageIcon(java.awt.Image)
	 */
	public StretchIcon(Image image) {
		super(image);
	}

	/**
	 * Creates a StretchIcon from the image with the specifiec 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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 StretchIcon 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) {
		if (getImage() == 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;
		Image image = getImage();

		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;
	}
}