ImageTransformTab.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.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.graphics.Transform;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Spinner;

/**
 * This tab demonstrates transformations, such as scaling, rotation, and invert. It allows the user to specify values
 * for scaling and rotation.
 */
public class ImageTransformTab extends GraphicsTab {

	private Button	invertButton;
	private Spinner	rotateSpinner, scaleSpinnerX, scaleSpinnerY;

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

	/**
	 * This method creates the controls specific to the tab. The call to the createControlPanel method in the super
	 * class create the controls that are defined in the super class.
	 * 
	 * @param parent
	 *            The parent composite
	 */
	public void createControlPanel(Composite parent) {

		Composite comp;
		GridLayout gridLayout = new GridLayout(2, false);

		// create spinner for the rotation angle
		comp = new Composite(parent, SWT.NONE);
		comp.setLayout(gridLayout);

		new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("Rotate")); //$NON-NLS-1$
		rotateSpinner = new Spinner(comp, SWT.BORDER | SWT.WRAP);
		rotateSpinner.setSelection(0);
		rotateSpinner.setMinimum(0);
		rotateSpinner.setMaximum(360);
		rotateSpinner.setIncrement(10);
		rotateSpinner.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event event) {
				example.redraw();
			}
		});

		// create a slider for scaling along the x axis
		comp = new Composite(parent, SWT.NONE);
		comp.setLayout(gridLayout);

		new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("xscale")); //$NON-NLS-1$
		scaleSpinnerX = new Spinner(comp, SWT.BORDER | SWT.WRAP);
		scaleSpinnerX.setDigits(2);
		scaleSpinnerX.setMinimum(1);
		scaleSpinnerX.setMaximum(500);
		scaleSpinnerX.setSelection(75);
		scaleSpinnerX.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event event) {
				example.redraw();
			}
		});

		// create a slider for scaling along the y axis
		comp = new Composite(parent, SWT.NONE);
		comp.setLayout(gridLayout);

		new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("yscale")); //$NON-NLS-1$
		scaleSpinnerY = new Spinner(comp, SWT.BORDER | SWT.WRAP);
		scaleSpinnerY.setDigits(2);
		scaleSpinnerY.setMinimum(1);
		scaleSpinnerY.setMaximum(500);
		scaleSpinnerY.setSelection(75);
		scaleSpinnerY.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event event) {
				example.redraw();
			}
		});

		// create a button for "invert"
		comp = new Composite(parent, SWT.NONE);
		comp.setLayout(new GridLayout());
		invertButton = new Button(comp, SWT.TOGGLE);
		invertButton.setText(GraphicsExample.getResourceString("Invert")); //$NON-NLS-1$
		invertButton.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event event) {
				example.redraw();
			}
		});
	}

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

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

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

	/*
	 * (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();

		Image image = GraphicsExample.loadImage(device, GraphicsExample.class, "ace_club.jpg");

		Transform transform = new Transform(device);

		// scale image
		transform.scale(scaleSpinnerX.getSelection() / 100f, scaleSpinnerY.getSelection() / 100f);

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

		if (invertButton.getSelection())
			transform.invert();

		gc.setTransform(transform);

		gc.drawImage(image, 0, 0);
		gc.drawRoundRectangle(0, 0, image.getBounds().width, image.getBounds().height, 22, 22);
		transform.dispose();
		image.dispose();
	}

}