/*
 * AboutDialog.java - About jEdit dialog box
 * :tabSize=8:indentSize=8:noTabs=false:
 * :folding=explicit:collapseFolds=1:
 *
 * Copyright (C) 2000, 2001, 2002 Slava Pestov
 *
 * This program 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 2
 * of the License, or any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package org.gjt.sp.jedit.gui;

//{{{ Imports
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import java.util.*;
import org.gjt.sp.jedit.*;
import org.gjt.sp.util.Log;
//}}}

public class AboutDialog extends JDialog implements ActionListener
{
	//{{{ AboutDialog constructor
	public AboutDialog(View view)
	{
		super(view,jEdit.getProperty("about.title"), true);
		setResizable(false);
		JButton closeBtn = new JButton(jEdit.getProperty("common.close"));
		closeBtn.addActionListener(this);
		getRootPane().setDefaultButton(closeBtn);

		JPanel p = new JPanel(new BorderLayout());
		AboutPanel aboutPanel = new AboutPanel();
		JPanel flowP = new JPanel(new FlowLayout());
		flowP.add(closeBtn);
		flowP.add(Box.createRigidArea(new Dimension(40, 40)));
		Dimension dim = new Dimension(10, 0);
		p.add(BorderLayout.WEST, Box.createRigidArea(dim));
		p.add(BorderLayout.EAST, Box.createRigidArea(dim));
		p.add(BorderLayout.NORTH, Box.createRigidArea(new Dimension(10, 10)));
		p.add(BorderLayout.SOUTH, flowP);
		p.add(BorderLayout.CENTER, aboutPanel);

		setContentPane(p);
		pack();
		Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
		setLocation((d.width-getWidth())/2, (d.height-getHeight())/2);
		addWindowListener(new WindowAdapter()
		{
			@Override
			public void windowClosing(WindowEvent e)
			{
				closeDialog();
			}
		});
		setVisible(true);
	} //}}}

	//{{{ actionPerformed() method
	public void actionPerformed(ActionEvent e)
	{
		closeDialog();
	} //}}}

	//{{{ closeDialog() method
	private void closeDialog()
	{
		AboutPanel.stopThread();
		dispose();
	} //}}}


	//{{{ AboutPanel class
	private static class AboutPanel extends JComponent implements Runnable
	{
		private BufferedImage bufImage;
		private Graphics2D g;
		private static final Font defaultFont = UIManager.getFont("Label.font");
		private final Font bottomLineFont = defaultFont.deriveFont(9.8f);
		private final String sBottomLine;
		private final ImageIcon image;
		private final Vector<String> vLines;
		private static boolean doWork;
		private Thread th;
		private final FontMetrics fm;
		private int iLineHeight = 0, iListHeight, iLineCount = 0,
			iBottomLineXOffset = 0, iBottomLineYOffset = 0,
			iPipeLineCount = 0, w = 0, h = 0, y = 0;
		private static final int
			SLEEP_TIME = 30,
			iBottomPadding = 36,
			iTopPadding = 120;
		private static Rectangle2D.Float rectangle;
		private static GradientPaint gradientPaint;

		AboutPanel()
		{
			String[] args = { jEdit.getVersion(), System.getProperty("java.version") };
			sBottomLine = jEdit.getProperty("about.version",args);
			setFont(defaultFont);
			fm = getFontMetrics(defaultFont);
			FontMetrics fmBottom = getFontMetrics(bottomLineFont);
			iLineHeight = fm.getHeight();
			vLines = new Vector<String>(50);
			image = (ImageIcon)GUIUtilities.loadIcon("about.png");
			MediaTracker tracker = new MediaTracker(this);
			tracker.addImage(image.getImage(), 0);

			try
			{
				tracker.waitForID(0);
			}
			catch(Exception exc)
			{
				tell("AboutPanel: " + exc);
			}

			Dimension d = new Dimension(image.getIconWidth(), image.getIconHeight());
			setSize(d);
			setPreferredSize(d);
			w = d.width;
			h = d.height;
			iBottomLineXOffset = (w / 2) - (fmBottom.stringWidth(sBottomLine) / 2);
			iBottomLineYOffset = h-iLineHeight/2;
			StringTokenizer st = new StringTokenizer(
				jEdit.getProperty("about.text"),"\n");
			while(st.hasMoreTokens())
			{
				vLines.add(st.nextToken());
			}

			iLineCount = vLines.size();
			iListHeight = iLineCount * iLineHeight;
			startThread();
			updateUI();
		}

		private void drain()
		{
			if (bufImage == null)
			{
				//pre-computing all data that can be known at this time
				Dimension d = getSize();
				bufImage = new BufferedImage(d.width, d.height,
					BufferedImage.TYPE_INT_RGB);
				g = bufImage.createGraphics();
				rectangle = new Rectangle2D.Float(0, iTopPadding,
					d.width, d.height-iBottomPadding-iTopPadding);
				//"+1" makes sure every new line from below comes up smoothly
				//cause it gets pre-painted and clipped as needed
				iPipeLineCount = 1 + (int)Math.ceil(rectangle.height/iLineHeight);
				y = d.height+iBottomPadding;
				g.setFont(defaultFont);
				gradientPaint = new GradientPaint(
					rectangle.width/2, iTopPadding+80, new Color(80, 80, 80),
					rectangle.width/2, iTopPadding, new Color(205, 205, 205)
					);
				g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
			}

			g.drawImage(image.getImage(), 0, 0, w, h, this);

			g.setFont(bottomLineFont);

			g.setPaint(new Color(55, 55, 55));
			g.drawString(sBottomLine, iBottomLineXOffset, iBottomLineYOffset);
			// Draw a highlight effect
			g.setPaint(new Color(255, 255, 255, 50));
			g.drawString(sBottomLine, iBottomLineXOffset + 1, iBottomLineYOffset + 1);

			g.setFont(defaultFont);
			g.setPaint(Color.black);


			g.drawRect(0, 0, w-1, h-1);
			g.clip(rectangle);
			g.setPaint(gradientPaint);
			int iDrawnLinesCount = 0, yCoor = 0;

			for (int i=0; i<iLineCount; i++)
			{
				//check whether the text line is above the canvas, if so, the code skips it
				yCoor = y+ i * iLineHeight;
				if (yCoor < iTopPadding)
				{
					continue;
				}

				//good to go, now draw only iPipeLineCount lines and get out from loop
				String sLine = vLines.get(i);
				int x = (w - fm.stringWidth(sLine))/2;
				g.drawString(sLine, x, yCoor);
				if (++iDrawnLinesCount >= iPipeLineCount)
				{
					break;
				}
			}

			y--;
			paint(getGraphics());

			//check if the end of the list has been reached,
			//if so rewind
			if ((y + iListHeight) < iTopPadding)
			{
				y = h+iBottomPadding;
			}
		}

		@Override
		public void update(Graphics g)
		{
			paint(g);
		}

		@Override
		public void paint(Graphics panelGraphics)
		{
			if (panelGraphics != null && bufImage != null)
			{
				panelGraphics.drawImage(bufImage, 0, 0, w, h, this);
			}
		}

		public void run()
		{
			try
			{
				while(doWork)
				{
					drain();
					Thread.sleep(SLEEP_TIME);
				}
			}
			catch(Exception exc)
			{
				Log.log(Log.ERROR, this, exc);
			}

			doWork = false;
			th = null;
		}

		public void startThread()
		{
			if (th == null)
			{
				th = new Thread(this);
				doWork = true;
				th.start();
			}
		}

		public static void stopThread()
		{
			doWork = false;
		}

		public static void tell(Object obj)
		{
			String str = obj == null ? "NULL" : obj.toString();
			JOptionPane.showMessageDialog(jEdit.getActiveView(), str, "Title", 1);
		}
	} //}}}
}