SquareHandle.java

/*******************************************************************************
 * Copyright (c) 2000, 2005 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.gef.handles;

import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Cursor;

import org.eclipse.draw2d.ColorConstants;
import org.eclipse.draw2d.Graphics;
import org.eclipse.draw2d.Locator;
import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Rectangle;

import org.eclipse.gef.EditPart;
import org.eclipse.gef.GraphicalEditPart;

/**
 * A small square handle approximately 7x7 pixels in size, that is either black or white.
 */
public abstract class SquareHandle
	extends AbstractHandle
{

/**
 * The default size for square handles.
 */
protected static final int DEFAULT_HANDLE_SIZE = 7;

{
	init();
}

/**
 * Null constructor
 */
public SquareHandle() { }

/**
 * Creates a SquareHandle for the given <code>GraphicalEditPart</code> with the given
 * <code>Locator</code>.
 * @param owner the owner
 * @param loc the locator
 */
public SquareHandle(GraphicalEditPart owner, Locator loc) {
	super(owner, loc);
}

/**
 * Creates a SquareHandle for the given <code>GraphicalEditPart</code> with the given
 * <code>Cursor</code> using the given <code>Locator</code>.
 * @param owner The editpart which provided this handle
 * @param loc The locator to position the handle
 * @param c The cursor to display when the mouse is over the handle
 */
public SquareHandle(GraphicalEditPart owner, Locator loc, Cursor c) {
	super(owner, loc, c);
}

/**
 * Returns the color for the outside of the handle.
 * @return the color for the border
 */
protected Color getBorderColor() {
	return (isPrimary())
		? ColorConstants.white
		: ColorConstants.black;
}

/**
 * Returns the color for the inside of the handle.
 * @return the color of the handle
 */
protected Color getFillColor() {
	return (isPrimary())
		? ColorConstants.black
		: ColorConstants.white;
}

/**
 * Initializes the handle.
 */
protected void init() {
	setPreferredSize(new Dimension(DEFAULT_HANDLE_SIZE, DEFAULT_HANDLE_SIZE));
}

/**
 * Returns <code>true</code> if the handle's owner is the primary selection.
 * @return <code>true</code> if the handles owner has primary selection.
 */
protected boolean isPrimary() {
	return getOwner().getSelected() == EditPart.SELECTED_PRIMARY;
}

/**
 * Draws the handle with fill color and outline color dependent 
 * on the primary selection status of the owner editpart.
 *
 * @param g The graphics used to paint the figure.
 */
public void paintFigure(Graphics g) {
	Rectangle r = getBounds();
	r.shrink(1, 1);
	try {
		g.setBackgroundColor(getFillColor());
		g.fillRectangle(r.x, r.y, r.width, r.height);
		g.setForegroundColor(getBorderColor()); 
		g.drawRectangle(r.x, r.y, r.width, r.height);
	} finally {
		//We don't really own rect 'r', so fix it.
		r.expand(1, 1);
	}
}

}