code: //==============================================================================
  //	
  //	Copyright (c) 2002-
  //	Authors:
  //	* Andrew Hinton <ug60axh@cs.bham.ac.uk> (University of Birmingham)
  //	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
  //	* Mark Kattenbelt <mark.kattenbelt@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
  //	* Charles Harley <cd.harley@talk21.com> (University of Edinburgh)
  //	* Sebastian Vermehren <seb03@hotmail.com> (University of Edinburgh)
  //	
  //------------------------------------------------------------------------------
  //	
  //	This file is part of PRISM.
  //	
  //	PRISM 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
  //	(at your option) any later version.
  //	
  //	PRISM 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 PRISM; if not, write to the Free Software Foundation,
  //	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  //	
  //==============================================================================
  
  package userinterface.model;
  
  import java.awt.Color;
  import java.awt.Font;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.RenderingHints;
  
  import javax.swing.text.BadLocationException;
  import javax.swing.text.DefaultEditorKit;
  import javax.swing.text.DefaultStyledDocument;
  import javax.swing.text.Document;
  import javax.swing.text.Element;
  import javax.swing.text.PlainView;
  import javax.swing.text.Segment;
  import javax.swing.text.StyleContext;
  import javax.swing.text.Utilities;
  import javax.swing.text.View;
  import javax.swing.text.ViewFactory;
  
  import prism.PrismLangException;
  import parser.PrismSyntaxHighlighter;
  
  /** Prism model editor kit for the text model editor. Defines the syntax
   * highlighting that the model editor should use.
   */
  class PrismEditorKit extends DefaultEditorKit
  {
  	
  	private PrismContext preferences;
  	private GUIMultiModelHandler handler;
  	
  	/** Creates a new instance of the Prism editor kit.
  	 * 
  	 * @param handler The GUI handler for this component.
  	 */
  	public PrismEditorKit(GUIMultiModelHandler handler)
  	{
  		this.handler = handler;
  	}
  
  	public PrismContext getStylePreferences()
  	{
  		if (preferences == null)
  		{
  			preferences = new PrismContext(handler);
  		}
  		return preferences;
  	}
  
  	public void setStylePreferences(PrismContext preferences)
  	{
  		this.preferences = preferences;
  	}
  
  	public String getContentType()
  	{
  		return "text/prism";
  	}
  
  	public Document createDefaultDocument()
  	{
  		return new DefaultStyledDocument();
  	}
  
  	public final ViewFactory getViewFactory()
  	{
  		return getStylePreferences();
  	}
  
  }
  
  class PrismContext extends StyleContext implements ViewFactory
  {
  
  	public static final String KEY_WORD_D = "Prism Keyword";
  	public static final String NUMERIC_D = "Numeric";
  	public static final String VARIABLE_D = "Variable";
  	public static final String COMMENT_D = "Single Line Comment";
  	
  	private GUIMultiModelHandler handler;
  	
  	/** Creates a new instance of PrismContext.
  	 * 
  	 * @param handler The GUI handler for this component. 
  	 */
  	public PrismContext(GUIMultiModelHandler handler)
  	{
  		this.handler = handler;
  	}
  
  	public View create(Element element)
  	{
  		return new PrismView(element, handler);
  	}
  
  }
  
  class PrismView extends PlainView
  {
  	
  	static final Style PLAIN_S = new Style(Color.black, Font.PLAIN);
  	
  	private GUIMultiModelHandler handler;
  
  	public PrismView(Element element, GUIMultiModelHandler handler)
  	{
  		super(element);
  		this.handler = handler;
  	}
  
  	protected int drawUnselectedText(Graphics g, int x, int y,int p0, int p1) throws BadLocationException
  	{
  		int stLine = p0;// findStartOfLine(p0, getDocument());
  		int enLine = p1;// findEndOfLine(p1-1, getDocument());
  
  		if (g instanceof Graphics2D) {
  			Graphics2D g2d = (Graphics2D)g;
  			g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
  		}
          
  		// x+= getLeftInset();
  		// System.out.println("p0 = "+p0+", p1 = "+p1+", st = "+stLine+",
  		// enLine = "+enLine+".");
  		try
  		{
  			g.setColor(Color.green);
  			Document doc = getDocument();
  			// Segment segment = getLineBuffer();
  
  			// System.out.println(doc.getText(p0, p1-p0));
  			// String s = doc.getText(p0, p1-p0);
  			String s = doc.getText(stLine, enLine-stLine);
  			// System.out.println("------");
  			// System.out.println("highlighting unselected string = \n"+s);
  			// System.out.println("------");
  
  			Style[] styles = highlight(s, (p0-stLine), (p1-p0));
  			int currStart = 0;
  			int currEnd = 0;
  			Color last = null;
  			String fname = handler.getPrismEditorFontFast().getName();
  			int fsize = handler.getPrismEditorFontFast().getSize();
  
  			for(int curr = 0; curr < styles.length; curr++)
  			{
  
  				Style c = styles[curr];
  
  				g.setColor(c.c);
  				g.setFont(new Font(fname, c.style, fsize));
  				Segment segm = new Segment();// getLineBuffer();
  				doc.getText(p0+curr, 1, segm);
  				x = Utilities.drawTabbedText(segm, x, y, g, this, p0+curr);
  
  			}
  			g.setColor(Color.black);
  			g.setFont(new Font(fname, Font.PLAIN, fsize));
  		}
  		catch(BadLocationException ex)
  		{
  			ex.printStackTrace();
  		}
  		return x;
  	}
  
  	protected int drawSelectedText(Graphics g, int x, int y,int p0, int p1) throws BadLocationException
  	{
  		int stLine = p0;// findStartOfLine(p0, getDocument());
  		int enLine = p1;// findEndOfLine(p1-1, getDocument());
  
  		if (g instanceof Graphics2D) {
  			Graphics2D g2d = (Graphics2D)g;
  			g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
  		}
          
  		// x+= getLeftInset();
  		// System.out.println("p0 = "+p0+", p1 = "+p1+", st = "+stLine+",
  		// enLine = "+enLine+".");
  		try
  		{
  			g.setColor(Color.green);
  			Document doc = getDocument();
  			// Segment segment = getLineBuffer();
  
  
  			// String s = doc.getText(p0, p1-p0);
  			// System.out.println(doc.getText(p0, p1-p0));
  
  
  			String s = doc.getText(stLine, enLine-stLine);
  			// System.out.println("------");
  			// System.out.println("highlighting selected string = \n"+s);
  			// System.out.println("------");
  			Style[] styles = highlight(s, (p0-stLine), (p1-p0));
  			int currStart = 0;
  			int currEnd = 0;
  			Color last = null;
  			String fname = handler.getPrismEditorFontFast().getName();
  			int fsize = handler.getPrismEditorFontFast().getSize();
  
  			for(int curr = 0; curr < styles.length; curr++)
  			{
  
  				Style c = styles[curr];
  
  				g.setColor(c.c);
  				g.setFont(new Font(fname, c.style, fsize));
  				Segment segm = new Segment();// getLineBuffer();
  				doc.getText(p0+curr, 1, segm);
  				x = Utilities.drawTabbedText(segm, x, y, g, this, p0+curr);
  
  			}
  			g.setColor(Color.black);
  			g.setFont(new Font(fname, Font.PLAIN, fsize));
  		}
  		catch(BadLocationException ex)
  		{
  			ex.printStackTrace();
  		}
  		return x;
  	}
  
  	private synchronized Style[] highlight(String s, int offset, int length)
  	{
  		int typeArray[];
  		int i, n;
  		if(!s.endsWith("\n"))
  			s += "\n";
  		// s = s.substring(0, s.length()-1);
  
  		try
  		{
  			typeArray = PrismSyntaxHighlighter.lineForPrismGUI(s);
  		}
  		catch (PrismLangException e)
  		{
  			n = s.length();
  			typeArray = new int[n];
  			for (i = 0; i < n; i++)
  				typeArray[i] = PrismSyntaxHighlighter.PUNCTUATION;
  		}
  
  		Style[] ret = new Style[length];
  		for (i = 0; i < length; i++)
  		{
  
  			if(i+offset < typeArray.length)
  			{
  				switch (typeArray[i+offset])
  				{
  				case PrismSyntaxHighlighter.PUNCTUATION: ret[i] = PLAIN_S; break;
  				case PrismSyntaxHighlighter.COMMENT: ret[i] = handler.getPrismEditorCommentFast(); break;
  				case PrismSyntaxHighlighter.WHITESPACE: ret[i] = PLAIN_S; break;
  				case PrismSyntaxHighlighter.KEYWORD: ret[i] = handler.getPrismEditorKeywordFast(); break;
  				case PrismSyntaxHighlighter.NUMERIC: ret[i] = handler.getPrismEditorNumericFast(); break;
  				case PrismSyntaxHighlighter.IDENTIFIER: ret[i] = handler.getPrismEditorVariableFast(); break;
  				default: ret[i] = PLAIN_S; break;
  				}
  			}
  			else ret[i] = PLAIN_S;
  
  		}
  
  		return ret;
  	}
  
  	// Legacy code, kept in just in case the original developers decide they need it.
  	/*private synchronized int findStartOfLine(int p0, Document d)
  	{
  		int index = p0;
  		String s = "";
  		try
  		{
  			s = d.getText(index, 1);
  		}
  		catch(BadLocationException e)
  		{
  			return 0;
  		}
  		index--;
  		if(!(!s.equals("\n") && index >= -1)) index--;// botch of the
  		// century, an
  		// alternative good
  		// code
  		while(!s.equals("\n") && index >= -1)
  		{
  			try
  			{
  				s = d.getText(index, 1);
  			}
  			catch(BadLocationException e)
  			{
  				return 0;
  			}
  			index--;
  		}
  		index+=2;
  		return index;
  	}
  
  	private synchronized int findEndOfLine(int p1, Document d)
  	{
  		int index = p1;
  		String s = "";
  		try
  		{
  			s = d.getText(index, 1);
  		}
  		catch(BadLocationException e)
  		{
  			return d.getLength();
  		}
  		index++;
  		while(!s.equals("\n") && index <= d.getLength())
  		{
  			try
  			{
  				s = d.getText(index, 1);
  			}
  			catch(BadLocationException e)
  			{
  				return d.getLength()-1;
  			}
  			index++;
  		}
  		index--;
  		return index;
  	}*/
  
  }
  