/*
    * Copyright (c) 2003-2008 by Cosylab d. d.
    *
    * This file is part of CosyBeans-Common.
    *
    * CosyBeans-Common is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
   *
   * CosyBeans-Common 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with CosyBeans-Common.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package com.cosylab.gui.components;
  
  import java.awt.BorderLayout;
  import java.awt.Color;
  import java.awt.Dimension;
  import java.awt.GradientPaint;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.image.BufferedImage;
  
  import javax.swing.Icon;
  import javax.swing.JFrame;
  
  import com.cosylab.gui.components.util.ColorHelper;
  
  
  /**
   * A label that paints a gradient as a background. User can specify gradient
   * colors (one of them is the default label background) and direction (the
   * default is from the upper left to the upper right corner) relative to the
   * label's proportions.
   *
   * @author <a href="mailto:miha.kadunc@cosylab.com">Miha Kadunc</a>
   * @version $id$
   */
  public class GradientLabel extends ResizableTextLabel
  {
  	private static final long serialVersionUID = 1L;
  	private Color backgroundOther = ColorHelper.getControlShadow();
  	private BufferedImage daBuffer = null;
  	private double endX = 1;
  	private double endY = 0;
  	private boolean gradientEnabled = true;
  	private double startX = 0.2f;
  	private double startY = 0;
  	
  	/**
  	 * Constructs an empty GradientLabel
  	 */
  	public GradientLabel()
  	{
  		super();
  		setOpaque(true);
  	}
  
  	/**
  	 * Constructs a GradientLabel with the specified icon.
  	 *
  	 * @param image
  	 */
  	public GradientLabel(Icon image)
  	{
  		super(image);
  		setOpaque(true);
  	}
  
  	/**
  	 * Constructor for GradientLabel.
  	 *
  	 * @param image
  	 * @param horizontalAlignment
  	 */
  	public GradientLabel(Icon image, int horizontalAlignment)
  	{
  		super(image, horizontalAlignment);
  		setOpaque(true);
  	}
  	
  	
  
  	/**
  	 * Constructs a GradientLabel with the specified text.
  	 *
  	 * @param text
  	 */
  	public GradientLabel(String text)
  	{
  		super(text);
  		setOpaque(true);
  	}
 
 	/**
 	 * Constructor for GradientLabel.
 	 *
 	 * @param text
 	 * @param icon
 	 * @param horizontalAlignment
 	 */
 	public GradientLabel(String text, Icon icon, int horizontalAlignment)
 	{
 		super(text, icon, horizontalAlignment);
 		setOpaque(true);
 	}
 
 	/**
 	 * Constructor for GradientLabel.
 	 *
 	 * @param text
 	 * @param horizontalAlignment
 	 */
 	public GradientLabel(String text, int horizontalAlignment)
 	{
 		super(text, horizontalAlignment);
 		setOpaque(true);
 	}
 
 	private void clearBuffer()
 	{
 		synchronized (this) {
 			daBuffer = null;
 		}
 	}
 
 	/**
 	 * Returns the backgroundStart, this is the color that is used for the
 	 * start of label's gradient. The end color is that of the label's
 	 * background.
 	 *
 	 * @return Color
 	 */
 	public Color getBackgroundStart()
 	{
 		return backgroundOther;
 	}
 
 	/**
 	 * Returns whether the gradient background is enabled.
 	 *
 	 * @return boolean
 	 */
 	public boolean isGradientEnabled()
 	{
 		return gradientEnabled;
 	}
 
 	/**
 	 * @see javax.swing.JComponent#paintComponent(java.awt.Graphics)
 	 */
 	protected void paintComponent(Graphics g)
 	{
 		boolean oldOpaque = isOpaque();
 
 		if (oldOpaque && (isGradientEnabled())) {
 			int w = getWidth();
 			int h = getHeight();
 
 			synchronized (this) {
 				if ((daBuffer == null) || (daBuffer.getWidth() != w)
 				    || (daBuffer.getHeight() != h)) {
 					daBuffer = new BufferedImage(w, h,
 						    BufferedImage.TYPE_3BYTE_BGR);
 
 					Graphics2D g2d = daBuffer.createGraphics();
 					g2d.setPaint(new GradientPaint((int)(startX * w),(int)(startY * h),
 					        getBackgroundStart(), (int)(endX * w), (int)(endY * h),
 					        getBackground()));
 					g2d.fillRect(0, 0, w, h);
 				}
 
 				g.drawImage(daBuffer, 0, 0, this);
 			}
 		}
 
 		if (isGradientEnabled()) {
 			setOpaque(false);
 		}
 
 		super.paintComponent(g);
 		super.setOpaque(oldOpaque);
 	}
 
 	/**
 	 * Sets the background color. This color is used for the gradient's end
 	 * point.
 	 *
 	 * @param c The color to be set
 	 *
 	 * @see java.awt.Component#setBackground(Color)
 	 * @see #setBackgroundStart(Color)
 	 */
 	public void setBackground(Color c)
 	{
 		if (!c.equals(getBackground())) {
 			clearBuffer();
 			super.setBackground(c);
 		}
 	}
 
 	/**
 	 * Sets the backgroundStart color.
 	 *
 	 * @param newBackgroundStart The backgroundStart to set
 	 *
 	 * @see #getBackgroundStart()
 	 */
 	public void setBackgroundStart(Color newBackgroundStart)
 	{
 		if (newBackgroundStart != null
 		    && !newBackgroundStart.equals(backgroundOther)) {
 			Color oldBackgroundStart = backgroundOther;
 			backgroundOther = newBackgroundStart;
 			clearBuffer();
 			repaint();
 			firePropertyChange("backgroundStart", oldBackgroundStart,
 			    newBackgroundStart);
 		}
 	}
 
 	/**
 	 * Sets the gradientEnabled property.
 	 *
 	 * @param gradientEnabled The gradientEnabled to set
 	 *
 	 * @see #isGradientEnabled()
 	 */
 	public void setGradientEnabled(boolean gradientEnabled)
 	{
 		this.gradientEnabled = gradientEnabled;
 		clearBuffer();
 	}
 
 	/**
 	 * Sets the start and end point of the label's gradient, relative to the
 	 * label's size. Value 0 is the left/top edge of the label. 1 is the
 	 * right/bottom edge of the label.
 	 *
 	 * @param startX the x coordinate of the start of the gradient
 	 * @param startY the y coordinate of the start of the gradient
 	 * @param endX the x coordinate of the end of the gradient
 	 * @param endY the y coordinate of the end of the gradient
 	 */
 	public void setGradientPoints(double startX, double startY, double endX,
 	    double endY)
 	{
 		this.startX = startX;
 		this.startY = startY;
 		this.endX = endX;
 		this.endY = endY;
 		clearBuffer();
 	}
 	
 	public static void main(String[] args) {
 		JFrame f = new JFrame();
 		f.getContentPane().setLayout(new BorderLayout());
 		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 		f.setSize(new Dimension(200,100));
 		f.getContentPane().add(new GradientLabel());
 		f.setVisible(true);
 	}
 }
 
 /* __oOo__ */