RGBTab.java

/*******************************************************************************
 * Copyright (c) 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.swt.examples.graphics;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Path;
import org.eclipse.swt.graphics.Pattern;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Transform;

/**
 * Miscellaneous tab that demonstrates emerging colors from layering other colors.
 */
public class RGBTab extends AnimatedGraphicsTab {

	float	diagTranslateX1, diagTranslateX2, diagTranslateY1, diagTranslateY2;
	int		translateX, translateY;

	/**
	 * Constructor
	 * 
	 * @param example
	 *            A GraphicsExample
	 */
	public RGBTab(GraphicsExample example) {
		super(example);
		translateX = translateY = 0;
		diagTranslateX1 = diagTranslateX2 = diagTranslateY1 = diagTranslateY2 = 0;
	}

	public String getCategory() {
		return GraphicsExample.getResourceString("Misc"); //$NON-NLS-1$
	}

	public String getDescription() {
		return GraphicsExample.getResourceString("rgbDescription"); //$NON-NLS-1$
	}

	public String getText() {
		return GraphicsExample.getResourceString("rgb"); //$NON-NLS-1$
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.examples.graphics.AnimatedGraphicsTab#next(int, int)
	 */
	public void next(int width, int height) {

		float h = height;
		float w = width;

		translateX = (translateX + 3) % width;
		translateY = (translateY + 5) % height;

		diagTranslateX1 = (diagTranslateX1 + 6) % width;
		diagTranslateY1 = diagTranslateX1 * h / w;

		diagTranslateX2 = (diagTranslateX2 + 8) % width;
		diagTranslateY2 = -diagTranslateX2 * h / w + h;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.swt.examples.graphics.GraphicsTab#paint(org.eclipse.swt.graphics.GC, int, int)
	 */
	public void paint(GC gc, int width, int height) {
		if (!example.checkAdvancedGraphics())
			return;
		Device device = gc.getDevice();

		// horizontal rectangle
		Transform transform = new Transform(device);
		transform.translate(0, translateY);
		gc.setTransform(transform);
		transform.dispose();

		Path path = new Path(device);
		path.addRectangle(0, 0, width, 50);
		Pattern pattern = new Pattern(device, 0, 0, width, 50, device.getSystemColor(SWT.COLOR_BLUE), 0x7f, device
				.getSystemColor(SWT.COLOR_RED), 0x7f);
		gc.setBackgroundPattern(pattern);
		gc.fillPath(path);
		gc.drawPath(path);
		path.dispose();

		// vertical rectangle
		transform = new Transform(device);
		transform.translate(translateX, 0);
		gc.setTransform(transform);
		transform.dispose();

		path = new Path(device);
		path.addRectangle(0, 0, 50, height);
		pattern.dispose();
		pattern = new Pattern(device, 0, 0, 50, height, device.getSystemColor(SWT.COLOR_DARK_CYAN), 0x7f, device
				.getSystemColor(SWT.COLOR_WHITE), 0x7f);
		gc.setBackgroundPattern(pattern);
		gc.fillPath(path);
		gc.drawPath(path);
		path.dispose();

		// diagonal rectangle from bottom right corner
		Rectangle rect = new Rectangle(0, 0, 50, height);
		transform = new Transform(device);
		transform.translate(width - diagTranslateX1, height / 2 - diagTranslateY1);

		// rotate on center of rectangle
		transform.translate(rect.width / 2, rect.height / 2);
		transform.rotate(45);
		transform.translate(-rect.width / 2, -rect.height / 2);
		gc.setTransform(transform);
		transform.dispose();

		path = new Path(device);
		path.addRectangle(rect.x, rect.y, rect.width, rect.height);
		pattern.dispose();
		pattern = new Pattern(device, rect.x, rect.y, rect.width, rect.height, device
				.getSystemColor(SWT.COLOR_DARK_GREEN), 0x7f, device.getSystemColor(SWT.COLOR_DARK_MAGENTA), 0x7f);
		gc.setBackgroundPattern(pattern);
		gc.fillPath(path);
		gc.drawPath(path);
		path.dispose();

		// diagonal rectangle from top right corner
		transform = new Transform(device);
		transform.translate(width - diagTranslateX2, height / 2 - diagTranslateY2);

		// rotate on center of rectangle
		transform.translate(rect.width / 2, rect.height / 2);
		transform.rotate(-45);
		transform.translate(-rect.width / 2, -rect.height / 2);
		gc.setTransform(transform);
		transform.dispose();

		path = new Path(device);
		path.addRectangle(rect.x, rect.y, rect.width, rect.height);
		pattern.dispose();
		pattern = new Pattern(device, rect.x, rect.y, rect.width, rect.height, device
				.getSystemColor(SWT.COLOR_DARK_RED), 0x7f, device.getSystemColor(SWT.COLOR_YELLOW), 0x7f);
		gc.setBackgroundPattern(pattern);
		gc.fillPath(path);
		gc.drawPath(path);
		pattern.dispose();
		path.dispose();
	}

}