CardsTab.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.graphics.Device;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Transform;

/**
 * This tab demonstrates various transformations, such as scaling, rotation, and translation.
 */
public class CardsTab extends AnimatedGraphicsTab {

	Image	ace_club, ace_spade, ace_diamond, ace_hearts;
	int		clubWidth, diamondWidth, heartWidth, spadeHeight;
	float	heartScale		= 0.5f;
	float	inc_club		= 5.0f;
	float	inc_diamond		= 5.0f;
	float	inc_hearts		= 5.0f;
	float	inc_spade		= 5.0f;
	float	movClubX, movClubY, movDiamondX, movDiamondY, movHeart, movSpade;
	int		rotationAngle	= 0;
	float	scale, scaleWidth;
	float	scaleArg		= 0;

	float	spadeScale		= 0.333f;

	/**
	 * Constructor
	 * 
	 * @param example
	 *            A GraphicsExample
	 */
	public CardsTab(GraphicsExample example) {
		super(example);
	}

	public void dispose() {
		if (ace_club != null) {
			ace_club.dispose();
			ace_club = null;
			ace_spade.dispose();
			ace_spade = null;
			ace_diamond.dispose();
			ace_diamond = null;
			ace_hearts.dispose();
			ace_hearts = null;
		}
	}

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

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

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

	public void next(int width, int height) {
		rotationAngle = (rotationAngle + 10) % 360;

		// scaleVal goes from 0 to 1, then 1 to 0, then starts over
		scaleArg = (float) (scaleArg == 1 ? scaleArg - 0.1 : scaleArg + 0.1);
		scale = (float) Math.cos(scaleArg);

		movClubX += inc_club;
		movDiamondX += inc_diamond;
		movHeart += inc_hearts;
		movSpade += inc_spade;

		scaleWidth = (float) (movClubY / height * 0.35 + 0.15);
		movClubY = 2 * height / 5 * (float) Math.sin(0.01 * movClubX - 90) + 2 * height / 5;
		movDiamondY = 2 * height / 5 * (float) Math.cos(0.01 * movDiamondX) + 2 * height / 5;

		if (movClubX + clubWidth * scaleWidth > width) {
			movClubX = width - clubWidth * scaleWidth;
			inc_club = -inc_club;
		}
		if (movClubX < 0) {
			movClubX = 0;
			inc_club = -inc_club;
		}
		if (movDiamondX + diamondWidth * scaleWidth > width) {
			movDiamondX = width - diamondWidth * scaleWidth;
			inc_diamond = -inc_diamond;
		}
		if (movDiamondX < 0) {
			movDiamondX = 0;
			inc_diamond = -inc_diamond;
		}
		if (movHeart + heartWidth * heartScale > width) {
			movHeart = width - heartWidth * heartScale;
			inc_hearts = -inc_hearts;
		}
		if (movHeart < 0) {
			movHeart = 0;
			inc_hearts = -inc_hearts;
		}
		if (movSpade + spadeHeight * spadeScale > height) {
			movSpade = height - spadeHeight * spadeScale;
			inc_spade = -inc_spade;
		}
		if (movSpade < 0) {
			movSpade = 0;
			inc_spade = -inc_spade;
		}
	}

	/*
	 * (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();

		if (ace_club == null) {
			ace_club = GraphicsExample.loadImage(device, GraphicsExample.class, "ace_club.jpg");
			ace_spade = GraphicsExample.loadImage(device, GraphicsExample.class, "ace_spade.jpg");
			ace_diamond = GraphicsExample.loadImage(device, GraphicsExample.class, "ace_diamond.jpg");
			ace_hearts = GraphicsExample.loadImage(device, GraphicsExample.class, "ace_hearts.jpg");
		}

		clubWidth = ace_club.getBounds().width;
		diamondWidth = ace_diamond.getBounds().width;
		heartWidth = ace_hearts.getBounds().width;
		spadeHeight = ace_spade.getBounds().height;

		Transform transform;

		// ace of clubs
		transform = new Transform(device);
		transform.translate((int) movClubX, (int) movClubY);
		transform.scale(scaleWidth, scaleWidth);

		// rotate on center of image
		Rectangle rect = ace_club.getBounds();
		transform.translate(rect.width / 2, rect.height / 2);
		transform.rotate(rotationAngle);
		transform.translate(-rect.width / 2, -rect.height / 2);

		gc.setTransform(transform);
		transform.dispose();
		gc.drawImage(ace_club, 0, 0);

		// ace of diamonds
		transform = new Transform(device);
		transform.translate((int) movDiamondX, (int) movDiamondY);
		transform.scale(scaleWidth, scaleWidth);
		gc.setTransform(transform);
		transform.dispose();
		gc.drawImage(ace_diamond, 0, 0);

		// ace of hearts
		transform = new Transform(device);
		transform.translate(movHeart, height / 2);
		transform.scale(heartScale, 0.5f * scale);
		gc.setTransform(transform);
		transform.dispose();
		gc.drawImage(ace_hearts, 0, 0);

		// ace of spades
		transform = new Transform(device);
		transform.translate(movSpade, movSpade);
		transform.scale(0.5f * scale, spadeScale);
		gc.setTransform(transform);
		transform.dispose();
		gc.drawImage(ace_spade, 0, 0);
	}
}