/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.ui.swing.util;

import java.awt.Component;
import java.awt.Container;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.URL;

import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRootPane;
import javax.swing.SwingUtilities;
import javax.swing.Timer;

/**
 * Visually highlights a component with the specified image for a brief period.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 904 $ $Date: 2006-02-18 18:19:05 -0500 (Sat, 18 Feb 2006)
 *          $
 */
public class ComponentHighlighter implements ActionListener {
	// lots of state to track
	JRootPane rootPane;
	JComponent component;
	Component oldGlassPane;
	JLabel imageLabel;
	Timer timer;
	JPanel glassPane;

	/**
	 * Alternate "Fire-and-forget" constructor loads an image from a URL.
	 * 
	 * @param aComponent A Component that will be highlighted.
	 * @param aURL       A URL pointing to an image.
	 */
	public ComponentHighlighter(JComponent aComponent, URL aURL) {
		if (aURL == null)
			return;
		init(aComponent, Toolkit.getDefaultToolkit().getImage(aURL));
	}

	/**
	 * "Fire-and-forget" constructor.
	 * 
	 * @param aComponent A Component that will be highlighted.
	 * @param anImage    An image, preferably an animated GIF with transparency,
	 *                   that will slide along the length of the component.
	 */
	public ComponentHighlighter(JComponent aComponent, Image anImage) {
		init(aComponent, anImage);
	}

	protected void init(JComponent aComponent, Image anImage) {
		if ((aComponent == null) || (anImage == null))
			return;

		component = aComponent;
		rootPane = SwingUtilities.getRootPane(component);
		oldGlassPane = rootPane.getGlassPane();

		glassPane = new JPanel();
		rootPane.setGlassPane(glassPane);
		glassPane.setVisible(true);
		glassPane.setOpaque(false);
		glassPane.setLayout(null);

		ImageIcon icon = new ImageIcon(anImage);

		imageLabel = new JLabel();
		imageLabel.setIconTextGap(0);
		imageLabel.setIcon(icon);
		imageLabel.setSize(icon.getIconWidth(), icon.getIconHeight());
		glassPane.add(imageLabel);

		Rectangle bounds = component.getBounds();
		if (component.getParent() instanceof Component) {
			bounds = SwingUtilities.convertRectangle((Container) component.getParent(), bounds,
					rootPane.getContentPane());
		}
		imageLabel.setLocation(bounds.x, bounds.y + bounds.height - imageLabel.getBounds().height);

		glassPane.revalidate();
		glassPane.repaint();

		component.transferFocus(); // halts a caret, if necessary

		timer = new Timer(80, this);
		timer.setRepeats(true);
		timer.start();
	}

	public void actionPerformed(ActionEvent evt) {
		Rectangle bounds = imageLabel.getBounds();
		Rectangle target = component.getBounds();
		if (component.getParent() instanceof Component) {
			target = SwingUtilities.convertRectangle((Container) component.getParent(), target,
					rootPane.getContentPane());
		}

		if (bounds.x + bounds.width > target.x + target.width) { // clean up and end
			timer.stop();
			rootPane.setGlassPane(oldGlassPane);
			component.requestFocus();
			return;
		}

		// else, slide to the right and continue
		imageLabel.setLocation(bounds.x + Math.max(bounds.width / 12, 1), bounds.y);
		imageLabel.repaint();
	}
}

/*
 * $Log$ Revision 1.2 2006/02/18 23:19:05 cgruber Update imports and maven
 * dependencies.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.1.1.1 2000/12/21 15:51:18 mpowers Contributing wotonomy.
 *
 * Revision 1.2 2000/12/20 16:25:45 michael Added log to all files.
 *
 *
 */