Paint a check pattern, used for a background to indicate image transparency. - Java 2D Graphics

Java examples for 2D Graphics:Image

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Description

Paint a check pattern, used for a background to indicate image transparency.

Demo Code


//package com.java2s;
import java.awt.*;

import java.awt.image.*;

public class Main {
    private static BufferedImage backgroundImage = null;

    /**/*from  ww w. ja v a2s.  co  m*/
     * Paint a check pattern, used for a background to indicate image transparency.
     * @param c the component to draw into
     * @param g the Graphics objects
     * @param x the x position
     * @param y the y position
     * @param width the width
     * @param height the height
     */
    public static void paintCheckedBackground(Component c, Graphics g,
            int x, int y, int width, int height) {
        if (backgroundImage == null) {
            backgroundImage = new BufferedImage(64, 64,
                    BufferedImage.TYPE_INT_ARGB);
            Graphics bg = backgroundImage.createGraphics();
            for (int by = 0; by < 64; by += 8) {
                for (int bx = 0; bx < 64; bx += 8) {
                    bg.setColor(((bx ^ by) & 8) != 0 ? Color.lightGray
                            : Color.white);
                    bg.fillRect(bx, by, 8, 8);
                }
            }
            bg.dispose();
        }

        if (backgroundImage != null) {
            Shape saveClip = g.getClip();
            Rectangle r = g.getClipBounds();
            if (r == null)
                r = new Rectangle(c.getSize());
            r = r.intersection(new Rectangle(x, y, width, height));
            g.setClip(r);
            int w = backgroundImage.getWidth();
            int h = backgroundImage.getHeight();
            if (w != -1 && h != -1) {
                int x1 = (r.x / w) * w;
                int y1 = (r.y / h) * h;
                int x2 = ((r.x + r.width + w - 1) / w) * w;
                int y2 = ((r.y + r.height + h - 1) / h) * h;
                for (y = y1; y < y2; y += h)
                    for (x = x1; x < x2; x += w)
                        g.drawImage(backgroundImage, x, y, c);
            }
            g.setClip(saveClip);
        }
    }
}

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