/*******************************************************************************
 * Copyright (c) 2000, 2010 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.draw2d;

import org.eclipse.swt.graphics.Image;

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

/**
 * A Figure that simply contains an Image. Use this Figure, instead of a Label,
 * when displaying Images without any accompanying text. This figure is not
 * intended to have a layout mananger or children.
 * <P>
 * Note that it is the client's responsibility to dispose the given image. There
 * is no "free" resource management in draw2d.
 * 
 * @author Pratik Shah
 */
public class ImageFigure extends AbstractImageFigure {

	private Image img;
	private Dimension size = new Dimension();
	private int alignment;

	/**
	 * Constructor<br>
	 * The default alignment is <code>PositionConstants.CENTER</code>.
	 */
	public ImageFigure() {
		this(null, PositionConstants.CENTER);
	}

	/**
	 * Constructor<br>
	 * The default alignment is <code>PositionConstants.CENTER</code>.
	 * 
	 * @param image
	 *            The Image to be displayed
	 */
	public ImageFigure(Image image) {
		this(image, PositionConstants.CENTER);
	}

	/**
	 * Constructor
	 * 
	 * @param image
	 *            The Image to be displayed
	 * @param alignment
	 *            A PositionConstant indicating the alignment
	 * 
	 * @see ImageFigure#setImage(Image)
	 * @see ImageFigure#setAlignment(int)
	 */
	public ImageFigure(Image image, int alignment) {
		setImage(image);
		setAlignment(alignment);
	}

	/**
	 * @return The Image that this Figure displays
	 */
	public Image getImage() {
		return img;
	}

	/**
	 * Calculates the necessary size to display the Image within the figure's
	 * client area.
	 * 
	 * @see org.eclipse.draw2d.Figure#getPreferredSize(int, int)
	 */
	public Dimension getPreferredSize(int wHint, int hHint) {
		if (getInsets() == NO_INSETS)
			return size;
		Insets i = getInsets();
		return size.getExpanded(i.getWidth(), i.getHeight());
	}

	/**
	 * @see org.eclipse.draw2d.Figure#paintFigure(Graphics)
	 */
	protected void paintFigure(Graphics graphics) {
		super.paintFigure(graphics);

		if (getImage() == null)
			return;

		int x, y;
		Rectangle area = getBounds().getShrinked(getInsets());
		switch (alignment & PositionConstants.NORTH_SOUTH) {
		case PositionConstants.NORTH:
			y = area.y;
			break;
		case PositionConstants.SOUTH:
			y = area.y + area.height - size.height;
			break;
		default:
			y = (area.height - size.height) / 2 + area.y;
			break;
		}
		switch (alignment & PositionConstants.EAST_WEST) {
		case PositionConstants.EAST:
			x = area.x + area.width - size.width;
			break;
		case PositionConstants.WEST:
			x = area.x;
			break;
		default:
			x = (area.width - size.width) / 2 + area.x;
			break;
		}
		graphics.drawImage(getImage(), x, y);
	}

	/**
	 * Sets the alignment of the Image within this Figure. The alignment comes
	 * into play when the ImageFigure is larger than the Image. The alignment
	 * could be any valid combination of the following:
	 * 
	 * <UL>
	 * <LI>PositionConstants.NORTH</LI>
	 * <LI>PositionConstants.SOUTH</LI>
	 * <LI>PositionConstants.EAST</LI>
	 * <LI>PositionConstants.WEST</LI>
	 * <LI>PositionConstants.CENTER or PositionConstants.NONE</LI>
	 * </UL>
	 * 
	 * @param flag
	 *            A constant indicating the alignment
	 */
	public void setAlignment(int flag) {
		alignment = flag;
	}

	/**
	 * Sets the Image that this ImageFigure displays.
	 * <p>
	 * IMPORTANT: Note that it is the client's responsibility to dispose the
	 * given image.
	 * 
	 * @param image
	 *            The Image to be displayed. It can be <code>null</code>.
	 */
	public void setImage(Image image) {
		if (img == image)
			return;
		img = image;
		if (img != null)
			size = new Rectangle(image.getBounds()).getSize();
		else
			size = new Dimension();
		revalidate();
		notifyImageChanged();
		repaint();
	}

}