IntroTab.java

/*******************************************************************************
 * Copyright (c) 2000, 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 java.util.Random;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Path;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;

public class IntroTab extends AnimatedGraphicsTab {

	Font	font;
	Image	image;
	float	incX	= 10.0f;
	float	incY	= 5.0f;
	Random	random	= new Random();
	String	text	= GraphicsExample.getResourceString("SWT");
	int		textWidth, textHeight;
	float	x, y;

	public IntroTab(GraphicsExample example) {
		super(example);
	}

	public void dispose() {
		if (image != null)
			image.dispose();
		image = null;
		if (font != null)
			font.dispose();
		font = null;
	}

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

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

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

	public void next(int width, int height) {
		x += incX;
		y += incY;
		float random = (float) Math.random();
		if (x + textWidth > width) {
			x = width - textWidth;
			incX = random * -width / 16 - 1;
		}
		if (x < 0) {
			x = 0;
			incX = random * width / 16 + 1;
		}
		if (y + textHeight > height) {
			y = height - textHeight - 2;
			incY = random * -height / 16 - 1;
		}
		if (y < 0) {
			y = 0;
			incY = random * height / 16 + 1;
		}
	}

	public void paint(GC gc, int width, int height) {
		if (!example.checkAdvancedGraphics())
			return;
		Device device = gc.getDevice();
		if (image == null) {
			image = example.loadImage(device, "irmaos.jpg");
			Rectangle rect = image.getBounds();
			FontData fd = device.getSystemFont().getFontData()[0];
			font = new Font(device, fd.getName(), rect.height / 4, SWT.BOLD);
			gc.setFont(font);
			Point size = gc.stringExtent(text);
			textWidth = size.x;
			textHeight = size.y;
		}
		Path path = new Path(device);
		path.addString(text, x, y, font);
		gc.setClipping(path);
		Rectangle rect = image.getBounds();
		gc.drawImage(image, 0, 0, rect.width, rect.height, 0, 0, width, height);
		gc.setClipping((Rectangle) null);
		gc.setForeground(device.getSystemColor(SWT.COLOR_BLUE));
		gc.drawPath(path);
		path.dispose();
	}
}