bufferedimagebackgroundpainterstrategy.java

具有不同语法高亮的编辑器实例

/*
 * 01/22/2005
 *
 * BufferedImageBackgroundPainterStrategy.java - Renders an RTextAreaBase's
 * background as an image using a BufferedImage.
 * Copyright (C) 2005 Robert Futrell
 * [e-mail]
 * www.website.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
package org.fife.ui.rtextarea;

import java.awt.Graphics;
import java.awt.Image;


/**
 * A strategy for painting the background of an <code>RTextAreaBase</code>
 * as an image.  The image is always stretched to completely fill the
 * <code>RTextAreaBase</code>.<p>
 *
 * A <code>java.awt.image.BufferedImage</code> is used for rendering;
 * theoretically, for performance you should use
 * <code>java.awt.image.VolatileImage</code>; see
 * <code>org.fife.ui.RTextArea.VolatileImageBackgroundPainterStrategy</code>
 * for this.<p>
 *
 * You can set the scaling hint used when stretching/skewing the image
 * to fit in the <code>RTextAreaBase</code>'s background via the
 * <code>setScalingHint</code> method, but keep in mind the more
 * accurate the scaling hint, the less responsive your application will
 * be when stretching the window (as that's the only time the image's
 * size is recalculated).
 *
 * @author Robert Futrell
 * @version 0.1
 * @see org.fife.ui.rtextarea.ImageBackgroundPainterStrategy
 * @see org.fife.ui.rtextarea.VolatileImageBackgroundPainterStrategy
 */
public class BufferedImageBackgroundPainterStrategy
					extends ImageBackgroundPainterStrategy {

	private Image bgImage;


/*****************************************************************************/


	/**
	 * Constructor.
	 *
	 * @param ta The text area whose background we'll be painting.
	 */
	public BufferedImageBackgroundPainterStrategy(RTextAreaBase ta) {
		super(ta);
	}


/*****************************************************************************/


	/**
	 * Paints the image at the specified location.  This method assumes
	 * scaling has already been done, and simply paints the background
	 * image "as-is."
	 *
	 * @param g The graphics context.
	 * @param x The x-coordinate at which to paint.
	 * @param y The y-coordinate at which to paint.
	 */
	protected void paintImage(Graphics g, int x, int y) {
		if (bgImage != null)
			g.drawImage(bgImage, x,y, null);
	}


/*****************************************************************************/


	/**
	 * Rescales the displayed image to be the specified size.
	 *
	 * @param width The new width of the image.
	 * @param height The new height of the image.
	 * @param hint The scaling hint to use.
	 */
	protected void rescaleImage(int width, int height, int hint) {
		Image master = getMasterImage();
		if (master!=null) {
			bgImage = master.getScaledInstance(width,height, hint);
			tracker.addImage(bgImage, 1);
			try {
				tracker.waitForID(1);
			} catch (InterruptedException e) {
				e.printStackTrace();
				bgImage = null;
				return;
			} finally {
				tracker.removeImage(bgImage, 1);
			}
		}
		else {
			bgImage = null;
		}
	}


/*****************************************************************************/

}