Border.java

/*******************************************************************************
 * Copyright (c) 2000, 2010, 2012 IBM Corporation, Gerhardt Informatics Kft. 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
 *     Gerhardt Informatics Kft. - GEFGWT port
 *******************************************************************************/
package org.eclipse.draw2d;

import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Insets;
import org.eclipse.draw2d.geometry.Rectangle;

/**
 * A decoration on a Figure. A border may paint itself within the bounds of a
 * figure, and it may provide Insets which can affect how the figures children
 * are posiiton and painted.
 * <P>
 * A border instance may be used with multiple figure instances.
 */
public interface Border {

	/**
	 * Returns the Insets for this Border for the given Figure.
	 * 
	 * @param figure
	 *            The figure this border belongs to
	 * @return The insets
	 */
	Insets getInsets(IFigure figure);

	/**
	 * Returns the preferred width and height that this border would like to
	 * display itself properly.
	 * 
	 * @param figure
	 *            The figure
	 * @return The preferred size
	 */
	Dimension getPreferredSize(IFigure figure);

	/**
	 * Returns <code>true</code> if the Border completely fills the region
	 * defined in {@link #paint(IFigure, Graphics, Insets)}.
	 * 
	 * @return <code>true</code> if this border is opaque
	 */
	boolean isOpaque();

	/**
	 * Paints the border. The border should paint inside figure's
	 * {@link IFigure#getBounds()}, inset by the parameter <i>insets</i>. The
	 * border generally should not paint inside its own insets. More
	 * specifically, Border <i>b</i> should paint inside the rectangle:
	 * figure.getBounds().getCropped(insets) and outside of the rectangle:
	 * figure.getBounds().getCropped(insets).getCropped(getInsets()) where
	 * <i>inside</i> is defined as {@link Rectangle#contains(int, int)}.
	 * 
	 * @param figure
	 *            The figure this border belongs to
	 * @param graphics
	 *            The graphics object used for painting
	 * @param insets
	 *            The insets
	 */
	void paint(IFigure figure, Graphics graphics, Insets insets);

}