LineCapTab.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.Font;
import org.eclipse.swt.graphics.GC;
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.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Menu;

/**
 * This tab demonstrates various line caps applicable to a line.
 */
public class LineCapTab extends GraphicsTab {

	/**
	 * Returns the name of a valid font for the resident platform.
	 */
	static String getPlatformFont() {
		if (SWT.getPlatform() == "win32")
			return "Arial";
		else if (SWT.getPlatform() == "motif")
			return "Helvetica";
		else if (SWT.getPlatform() == "gtk")
			return "Baekmuk Batang";
		else if (SWT.getPlatform() == "carbon")
			return "Arial";
		else
			return "Verdana";
	}

	Button				colorButton;
	GraphicsBackground	foreground;

	Menu				menu;

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

	public void createControlPanel(Composite parent) {

		Composite comp;

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

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

		// initialize the foreground to the 3rd item in the menu (red)
		foreground = (GraphicsBackground) menu.getItem(2).getData();

		// color button
		colorButton = new Button(comp, SWT.PUSH);
		colorButton.setText(GraphicsExample.getResourceString("Color")); //$NON-NLS-1$
		colorButton.setImage(foreground.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("LineCapDescription"); //$NON-NLS-1$
	}

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

	public void paint(GC gc, int width, int height) {
		Device device = gc.getDevice();

		// draw side lines
		gc.setLineWidth(1);
		gc.setLineStyle(SWT.LINE_DOT);
		gc.setForeground(device.getSystemColor(SWT.COLOR_BLACK));
		gc.drawLine(3 * width / 16, height / 6, 3 * width / 16, 5 * height / 6);
		gc.drawLine(13 * width / 16, height / 6, 13 * width / 16, 5 * height / 6);
		gc.setLineStyle(SWT.LINE_SOLID);

		// draw labels
		Font font = new Font(device, LineCapTab.getPlatformFont(), 20, SWT.NORMAL);
		gc.setFont(font);

		String text = GraphicsExample.getResourceString("Flat"); //$NON-NLS-1$
		Point size = gc.stringExtent(text);
		gc.drawString(text, (width - size.x) / 2, 3 * height / 12, true);
		text = GraphicsExample.getResourceString("Square"); //$NON-NLS-1$
		size = gc.stringExtent(text);
		gc.drawString(text, (width - size.x) / 2, 5 * height / 12, true);
		text = GraphicsExample.getResourceString("Round"); //$NON-NLS-1$
		size = gc.stringExtent(text);
		gc.drawString(text, (width - size.x) / 2, 7 * height / 12, true);
		font.dispose();

		Pattern pattern = null;
		if (foreground.getBgColor1() != null)
			gc.setForeground(foreground.getBgColor1());
		else if (foreground.getBgImage() != null) {
			pattern = new Pattern(device, foreground.getBgImage());
			gc.setForegroundPattern(pattern);
		}

		// draw lines with caps
		gc.setLineWidth(20);
		gc.setLineCap(SWT.CAP_FLAT);
		gc.drawLine(3 * width / 16, 2 * height / 6, 13 * width / 16, 2 * height / 6);
		gc.setLineCap(SWT.CAP_SQUARE);
		gc.drawLine(3 * width / 16, 3 * height / 6, 13 * width / 16, 3 * height / 6);
		gc.setLineCap(SWT.CAP_ROUND);
		gc.drawLine(3 * width / 16, 4 * height / 6, 13 * width / 16, 4 * height / 6);

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