BufferedImageBackgroundPainterStrategy.java

/*
 * 01/22/2005
 *
 * BufferedImageBackgroundPainterStrategy.java - Renders an RTextAreaBase's
 * background as an image using a BufferedImage.
 * Copyright (C) 2005 Robert Futrell
 * robert_futrell at users.sourceforge.net
 * http://fifesoft.com/rsyntaxtextarea
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; 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;
        }
    }

}