HashedCircle.java

/******************************************************************************
 * Copyright (c) 2002, 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.gmf.runtime.draw2d.ui.figures;

import org.eclipse.draw2d.Ellipse;
import org.eclipse.draw2d.Graphics;
import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Point;

/**
 * A circle figure with hashed lines.
 * 
 * @author cmahoney
 */
public class HashedCircle extends Ellipse {

    /**
     * An enumeration describing the hash lines inside the circle.
     */
    public static final class HashType {
        private HashType() {
        	// empty constructor
        }

        /** Draws an 'X' through the circle */
        public static final HashType X = new HashType();

        /** Draws a '\' through the circle */
        public static final HashType BACKSLASH = new HashType();
    }

    /** The type of hash lines to draw - default 'X' */
    private HashType hashType = HashType.X;

	/**
	 * Creates a <code>HashedCircle</code>.
     * @param hashType The hashType to set
     * @param radius The radius to set
	 */
	public HashedCircle(HashType hashType, int radius) {
		super();
		this.hashType = hashType;
		int width = radius * 2;
		setSize(new Dimension(width, width));
		setMaximumSize(new Dimension(width, width));
	}

    protected void outlineShape(Graphics graphics) {
        // draw the circle
        super.outlineShape(graphics);

        // calculate the x and y shift from the center to the corners of the circle
        double radius = getBounds().width / 2.0;
        int xyShift = new Double(radius / Math.sqrt(2.0)).intValue();

        Point center = getBounds().getCenter();

        if (hashType == HashType.X || hashType == HashType.BACKSLASH) {
            Point topLeft = center.getTranslated(-xyShift, -xyShift);
            Point bottomRight = center.getTranslated(xyShift, xyShift);
            graphics.drawLine(topLeft, bottomRight);
        }

        if (hashType == HashType.X) {
            Point topRight = center.getTranslated(xyShift, -xyShift);
            Point bottomLeft = center.getTranslated(-xyShift, xyShift);
            graphics.drawLine(bottomLeft, topRight);
        }
    }

}