LineJoinTab.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.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
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.Menu;

/**
 * This tab demonstrates various line joins. It allows a user to choose from bevel, miter and round.
 */
public class LineJoinTab extends GraphicsTab {

	private Button				colorButton;
	private Combo				joinCb;
	private int[]				joinValues	= new int[] { SWT.JOIN_BEVEL, SWT.JOIN_MITER, SWT.JOIN_ROUND };
	private Menu				menu;
	private GraphicsBackground	shapeColor;

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

	public void createControlPanel(Composite parent) {

		// create drop down combo for choosing clipping
		Composite comp = new Composite(parent, SWT.NONE);
		comp.setLayout(new GridLayout(2, false));

		new Label(comp, SWT.CENTER).setText(GraphicsExample.getResourceString("LineJoin")); //$NON-NLS-1$
		joinCb = new Combo(comp, SWT.DROP_DOWN);
		joinCb.add(GraphicsExample.getResourceString("bevel")); //$NON-NLS-1$
		joinCb.add(GraphicsExample.getResourceString("miter")); //$NON-NLS-1$
		joinCb.add(GraphicsExample.getResourceString("round")); //$NON-NLS-1$
		joinCb.select(1);
		joinCb.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event event) {
				example.redraw();
			}
		});

		// color menu
		ColorMenu cm = new ColorMenu();
		cm.setPatternItems(example.checkAdvancedGraphics());
		menu = cm.createMenu(parent.getParent(), new ColorListener() {
			public void setColor(GraphicsBackground gb) {
				shapeColor = gb;
				colorButton.setImage(gb.getThumbNail());
				example.redraw();
			}
		});

		// initialize the shape color to the 4th item in the menu (green)
		shapeColor = (GraphicsBackground) menu.getItem(3).getData();

		// color button
		comp = new Composite(parent, SWT.NONE);
		comp.setLayout(new GridLayout(2, false));

		colorButton = new Button(comp, SWT.PUSH);
		colorButton.setText(GraphicsExample.getResourceString("Color")); //$NON-NLS-1$
		colorButton.setImage(shapeColor.getThumbNail());
		colorButton.addListener(SWT.Selection, new Listener() {
			public void handleEvent(Event event) {
				final Button button = (Button) event.widget;
				final Composite parent = button.getParent();
				Rectangle bounds = button.getBounds();
				Point point = parent.toDisplay(new Point(bounds.x, bounds.y));
				menu.setLocation(point.x, point.y + bounds.height);
				menu.setVisible(true);
			}
		});

	}

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

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

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

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

	public void paint(GC gc, int width, int height) {
		if (!example.checkAdvancedGraphics())
			return;
		Device device = gc.getDevice();

		gc.setLineWidth(20);
		gc.setLineJoin(joinValues[joinCb.getSelectionIndex()]);

		// set the foreground color or pattern
		Pattern pattern = null;
		if (shapeColor.getBgColor1() != null)
			gc.setForeground(shapeColor.getBgColor1());
		else if (shapeColor.getBgImage() != null) {
			pattern = new Pattern(device, shapeColor.getBgImage());
			gc.setForegroundPattern(pattern);
		}

		// draw the shape
		Path path = new Path(device);
		path.moveTo(width / 2, 25);
		path.lineTo(2 * width / 3, height / 3);
		path.lineTo(width - 25, height / 2);
		path.lineTo(2 * width / 3, 2 * height / 3);
		path.lineTo(width / 2, height - 25);
		path.lineTo(width / 3, 2 * height / 3);
		path.lineTo(25, height / 2);
		path.lineTo(width / 3, height / 3);
		path.lineTo(width / 2, 25);
		path.close();
		gc.drawPath(path);
		path.dispose();

		if (pattern != null)
			pattern.dispose();
	}

}