// KHSClient.java
// Written by Walter Piechulla in August 1999 for the seminar "Hypermedia"

// To read this code, set tab position of your editor to 2 (tab represented by 2 spaces) !!!

// This applet was written with Microsoft Visual J++ 1.1 (oh, what a scandal!). 
// Let me explain: I did it for practical reasons. 
// The Developer Studio is a very convenient programming workplace, and I was used to it 
// (I had done MFC and API-level programming with Visual C++). Visual J++ 1.1 is based 
// on the 1.0.2 version of JDK which is 'outdated' compared to the up to date Java 2 release
// (formerly known as Java 1.2). But this means, that the bytecode produced by J++ 1.1 runs on 
// virtually EVERY browser's JVM. At the time this is written (1999), no browser on the market
// has a Java 2 compatible JVM. Writing Java 2 Applets nowadays would mean forcing users to 
// install the browser plugin from Sun. While this is perfectly ok for serious intranet 
// applications, it would be complete nonsense for a simple demonstration like KHSClient.   

import java.util.*;
import java.awt.*;
import java.net.*;
import java.io.*;
import java.applet.Applet;

class Node
{
	String label;
	String theURL;
	Rectangle rc;
	Point center;
	boolean pushed;
	boolean selected;
	boolean hasContent;
	boolean isTerminal;
	boolean isUpper;
	boolean isDowner;

	public Node()
	{
		label = new String();
		theURL = new String();
		rc = new Rectangle();
		center = new Point(0,0);
		pushed = false;
		hasContent = true;
		isTerminal = false;
		isUpper = false;
		isDowner = false;	
		selected = false;
	}
}

class GrandDaughter extends Node
{
	public GrandDaughter()
	{
		// Nothing to do
	}
}

class Daughter extends Node
{
	Vector GrandDaughters;
	int distance2root;

	public Daughter()
	{
		GrandDaughters = new Vector(10,5);
	}
}

class Mother extends Node
{
	Vector Daughters;

	public Mother()
	{
		Daughters = new Vector(10,5);
	}
}

class LabelsManager
{
	Vector deadRectangles;
	boolean justPastDaughter;

	public LabelsManager()
	{
		deadRectangles = new Vector(10,5);
		justPastDaughter = false;
	}

	private Rectangle gloved(Rectangle naked,int gloveSize)
	{
		Rectangle withGlove = new Rectangle();
		withGlove.reshape(naked.x,naked.y,naked.width,naked.height);
		withGlove.grow(gloveSize,gloveSize);
		return withGlove;
	}
	
	private boolean anyCollision(Rectangle rc,int gloveSize)
	{
		for (Enumeration enum = deadRectangles.elements();enum.hasMoreElements();) 
		{
			Rectangle avoidMe = (Rectangle) enum.nextElement();

			if (avoidMe.intersects(gloved(rc,gloveSize)))
				return true;
		}

		return false;
	}

	// To understand this you must know that a Rectangle comes in with its true dimensions, 
	// but centered on its predecessor (to be improved)
	public Rectangle getAnotherLabelRc(int direction,Rectangle preparedRc,Rectangle avoidThisRc,int gloveSize)
	{
		Rectangle resultRc = new Rectangle(preparedRc.x,preparedRc.y,preparedRc.width,preparedRc.height);

		switch (direction)
		{
			case 3:	 // == going left down == drawing daughter == refresh 
				   justPastDaughter = true;
				   deadRectangles.removeAllElements();
			     deadRectangles.addElement(gloved(avoidThisRc,gloveSize));

			     while (anyCollision(resultRc,gloveSize))
			     {
				     resultRc.translate(-4,1);  // Go to the left, go downwards
			     }
				   break;	
			
			case 1: // Go to the right, go upwards
					 if (justPastDaughter)
					 {
					 	 deadRectangles.removeAllElements();
						 justPastDaughter = false;
					 }

					 deadRectangles.addElement(gloved(preparedRc,gloveSize));	

			     while (anyCollision(resultRc,gloveSize))
			     {
						 resultRc.translate(2,-1);
					 }
					 break;

			case 2: // Go to the right, go downwards
					 if (justPastDaughter)
					 {
					 	 deadRectangles.removeAllElements();
						 justPastDaughter = false;
					 }

					 deadRectangles.addElement(gloved(preparedRc,gloveSize));
			
			     while (anyCollision(resultRc,gloveSize))
			     {
						 resultRc.translate(2,1);
					 }
					 break;	
		}

		return resultRc;
	}

}

class GraphPanel extends Panel implements Runnable 
{
  public Mother theMother = new Mother();
	StringBuffer emergencyStringBuf = new StringBuffer();
	boolean fatalError = false;
	int antiCollisionMemorizer = 0;
	boolean newLayout = true;
	Image contentSymbol;
	Image upperSymbol;
	Image downerSymbol;
  Image offscreen;
  Dimension offscreensize;
  Graphics offgraphics;
	final Color backgroundColor = new Color(172,160,153);
	final Color standardAbgetoentesWeiss = new Color(255,251,240); // Marcellus Buchheit: Windows Programmierbuch p.83
	Color leveledColors[] = new Color[9];
	Frame BrowserFrame_;
	LabelsManager labelsManager = new LabelsManager();

	KHSClient graphObj;
  Thread relaxer;

  GraphPanel(KHSClient graphObj) 
	{
		this.graphObj = graphObj;
  }

  public void run() 
	{
		while (true) 
		{
	    relax();
	    
			try 
			{
				Thread.sleep(100);
	    } 
			catch (InterruptedException e) 
			{
				break;
	    }
		}
  }

	synchronized void relax() 
	{
		repaint(); 
  }

  public synchronized void update(Graphics g) 
	{
		Dimension d = size();
		antiCollisionMemorizer = 0; // Rewind avoid-predecessor-logic of getNiceNonIntersectingRc-method
		int focusLevel;             // How far away ist the daughter from root
	
		// Offscreen graphics context
		if ((offscreen == null) || (d.width != offscreensize.width) || (d.height != offscreensize.height)) 
		{
	    offscreen = createImage(d.width,d.height);
	    offscreensize = d;
	    offgraphics = offscreen.getGraphics();
	    offgraphics.setFont(getFont());
		}

		offgraphics.setColor(getBackground());
		offgraphics.fillRect(0,0,d.width,d.height);
	
		FontMetrics fm = offgraphics.getFontMetrics();
	
		if (!fatalError)
		{
			if (newLayout)
			{
				theMother.center.x = d.width/10*6;
				theMother.center.y = d.height/11;
				sizeAndPlaceTheLabel(theMother,fm,1);
			}
		
			// Knowing that there is actually only one daughter:
			Daughter soleDaughter = (Daughter) theMother.Daughters.elementAt(0);
			focusLevel = soleDaughter.distance2root;

			if (newLayout)		
			{
				passCenter(theMother,soleDaughter);
				sizeAndPlaceTheLabel(soleDaughter,fm,2);
				getNiceNonIntersectingRc(soleDaughter.rc,theMother.rc,5,true);
				updateCenter(soleDaughter);
			}

			offgraphics.setColor(Color.darkGray);
			offgraphics.drawLine(theMother.center.x,theMother.center.y,soleDaughter.center.x,soleDaughter.center.y);

			drawNode(offgraphics,leveledColors[focusLevel],fm,theMother,theMother.pushed);
			drawNode(offgraphics,leveledColors[focusLevel+1],fm,soleDaughter,soleDaughter.pushed);

			boolean firstGrandDaughter = true;

			Node lastNode = new Node();
			Node lastLastNode = new Node(); 
			lastLastNode = theMother; 
			lastNode = soleDaughter; 
		
			// Conection lines, some computations
			for (Enumeration enum = soleDaughter.GrandDaughters.elements();enum.hasMoreElements();) 
			{
				GrandDaughter grandDaughter = (GrandDaughter) enum.nextElement();
			
				if (newLayout)
				{
					passCenter(lastNode,grandDaughter);
					sizeAndPlaceTheLabel(grandDaughter,fm,3);
		  
					if (firstGrandDaughter)
					{
						getNiceNonIntersectingRc(grandDaughter.rc,soleDaughter.rc,80,true);
						firstGrandDaughter = false;
					}
					else
					{
						getNiceNonIntersectingRc(grandDaughter.rc,soleDaughter.rc,2,false);
					}
			
					updateCenter(grandDaughter);
				}
			
				offgraphics.setColor(Color.darkGray);
				offgraphics.drawLine(soleDaughter.center.x,soleDaughter.center.y,grandDaughter.center.x,grandDaughter.center.y);

				lastLastNode = lastNode;
				lastNode = grandDaughter;
			}

			// Draw labels
			for (Enumeration enum = soleDaughter.GrandDaughters.elements();enum.hasMoreElements();) 
			{
				GrandDaughter grandDaughter = (GrandDaughter) enum.nextElement();
				drawNode(offgraphics,leveledColors[focusLevel+2],fm,grandDaughter,grandDaughter.pushed);
			}

			// Redraw daughter, may be crossed by lines drawn
			drawNode(offgraphics,leveledColors[focusLevel+1],fm,soleDaughter,soleDaughter.pushed);
		}
		else
		{
			// Handling of fatal errors
			offgraphics.setColor(Color.black);
			offgraphics.drawString("Please notify walter.piechulla@psychologie.uni-regensburg.de of this problem:",2,10);
			offgraphics.drawString(emergencyStringBuf.toString(),2,30);
		}
		
		g.drawImage(offscreen,0,0,null);
		newLayout = false;
  }

	// Position: 1=up, 2=middle, 3=down
	private void sizeAndPlaceTheLabel(Node node,FontMetrics fm,int position)
	{
		node.rc.width = fm.stringWidth(node.label) + 10;

		if (node.hasContent)
		{
			node.rc.width += 20;
		}

		// Detect navigation role of label (if any): "upper" or "downer" 
		switch(position)
		{
			case 1: // Top: is an upper, if not root
							if (node.label.equals("?"))
							{
								node.isUpper = false;
								node.isDowner = false;
							} 
							else
							{
								node.isUpper = true;
								node.isDowner = false;
							}

							break;

			case 3: // Bottom: is a downer, if not a terminal unit
							if (node.isTerminal)
							{
								node.isDowner = false;
								node.isUpper = false;
							}
							else
							{
								node.isDowner = true;
								node.isUpper = false;
							}
							
							break;
			
			default: break;
		}

		if (node.isUpper || node.isDowner)
		{
			node.rc.width += 20;
		}

		node.rc.height = fm.getHeight() + 4;
		node.rc.x = node.center.x - node.rc.width/2;
		node.rc.y = node.center.y - node.rc.height/2;
	}

	private void updateCenter(Node node)
	{
		node.center.x = node.rc.x + node.rc.width/2;
		node.center.y = node.rc.y + node.rc.height/2;
	}

	private void passCenter(Node n1,Node n2)
	{
		n2.center.x = n1.center.x;
		n2.center.y = n1.center.y;
	}

	private void drawNode(Graphics g,Color color,FontMetrics fm,Node node,boolean pushed)
	{
		if (node.selected)
		{
			g.setColor(Color.white);
		}
		else
		{
			g.setColor(color);
		}

		g.fillRect(node.rc.x,node.rc.y,node.rc.width,node.rc.height);
		Point leftTop = new Point(node.rc.x,node.rc.y);
		Point rightBottom = new Point(node.rc.x+(node.rc.width-1),node.rc.y+(node.rc.height-1));

		if (pushed)
		{
			g.setColor(Color.darkGray);
		}	
		else
		{
			g.setColor(standardAbgetoentesWeiss);
		}
    
		g.drawLine(leftTop.x,rightBottom.y,leftTop.x,leftTop.y);
		g.drawLine(leftTop.x,leftTop.y,rightBottom.x,leftTop.y);

		if (pushed)
		{
			g.setColor(standardAbgetoentesWeiss);
		}
		else
		{
			g.setColor(Color.darkGray);		
		}
				
		g.drawLine(leftTop.x+1,rightBottom.y,rightBottom.x,rightBottom.y);
		g.drawLine(rightBottom.x,rightBottom.y,rightBottom.x,leftTop.y+1);
		g.setColor(Color.black);
		
		if (pushed) // Draw shifted one pixel to the right and one pixel down
		{
			if (node.hasContent)
			{
				if (node.isUpper)
				{
					g.drawImage(upperSymbol,1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2 - 7),fm.getHeight()+4,fm.getHeight()+8,this);
					g.drawImage(contentSymbol,1 + 20 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()+4,fm.getHeight()+4,this);
					g.drawString(node.label,1 + 40 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else if (node.isDowner)
				{
					g.drawImage(downerSymbol,1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()+4,fm.getHeight()+4,this);
					g.drawImage(contentSymbol,1 + 20 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()+4,fm.getHeight()+4,this);
					g.drawString(node.label,1 + 40 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else
				{ 
					g.drawImage(contentSymbol,1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()+4,fm.getHeight()+4,this);
					g.drawString(node.label,20 + 1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
			}
			else
			{
				if (node.isUpper)
				{
					g.drawImage(upperSymbol,1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2 - 7),fm.getHeight()+4,fm.getHeight()+8,this);
					g.drawString(node.label,1 + 20 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else if (node.isDowner)
				{
					g.drawImage(downerSymbol,1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()+4,fm.getHeight()+4,this);
					g.drawString(node.label,1 + 20 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else
				{
					g.drawString(node.label,1 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
			}
		}
		else
		{
			if (node.hasContent)
			{
				if (node.isUpper)
				{
					g.drawImage(upperSymbol,node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawImage(contentSymbol,20 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawString(node.label,40 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else if (node.isDowner)
				{
					g.drawImage(downerSymbol,node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawImage(contentSymbol,20 + node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawString(node.label,40 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else
				{
					g.drawImage(contentSymbol,node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawString(node.label,20 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
			}
			else
			{
				if (node.isUpper)
				{
					g.drawImage(upperSymbol,node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawString(node.label,20 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else if (node.isDowner)
				{
					g.drawImage(downerSymbol,node.center.x - (node.rc.width-10)/2,1 + (node.center.y - (node.rc.height-4)/2),fm.getHeight()-1,fm.getHeight()-1,this);
					g.drawString(node.label,20 + node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
				else
				{
					g.drawString(node.label,node.center.x - (node.rc.width-10)/2,(node.center.y - (node.rc.height-4)/2) + fm.getAscent());
				}
			}
		}
	}

	private void getNiceNonIntersectingRc(Rectangle dstRc,Rectangle avoidRc,int push,boolean drawDaughter)
	{
		int decision;

		if (drawDaughter)
		{
			decision = 3;
		}
		else
		{
			if (antiCollisionMemorizer < 2)
			{
				decision = 1;
				antiCollisionMemorizer++;
			}
			else 
			{
				decision = 2;
				antiCollisionMemorizer++;

				if (antiCollisionMemorizer == 4)
					antiCollisionMemorizer = 0;
			}
		}
		
		Rectangle templateRc = labelsManager.getAnotherLabelRc(decision,dstRc,avoidRc,push); 	
		dstRc.reshape(templateRc.x,templateRc.y,templateRc.width,templateRc.height);
	}

  public synchronized boolean mouseDown(Event evt,int x,int y) 
	{
		for (Enumeration enum = theMother.Daughters.elements();enum.hasMoreElements();)
		{
			Daughter daughter = (Daughter) enum.nextElement();

			for (Enumeration enum2 = daughter.GrandDaughters.elements();enum2.hasMoreElements();)
			{
				GrandDaughter grandDaughter = (GrandDaughter) enum2.nextElement();

				if (grandDaughter.rc.inside(x,y))
				{
					grandDaughter.pushed = true;
					grandDaughter.selected = true;
				}
				else
				{
					grandDaughter.selected = false;
				}
			}
		}

		if (theMother.rc.inside(x,y))
		{
			theMother.pushed = true;
			theMother.selected = true;
		}
		else
		{
			theMother.selected = false;
		}

		// One single daughter only 
		Daughter soleDaughter = (Daughter) theMother.Daughters.elementAt(0);
		
		if (soleDaughter.rc.inside(x,y)) 
		{
			soleDaughter.pushed = true;
			soleDaughter.selected = true;
		}
		else
		{
			soleDaughter.selected = false;
		}

		repaint(); // Immediately
		return true;
	}

  // Shape cursor to hand when it is located on a label
	public synchronized boolean mouseMove(Event evt,int x,int y)
	{
		for (Enumeration enum = theMother.Daughters.elements();enum.hasMoreElements();)
		{
			Daughter daughter = (Daughter) enum.nextElement();

			for (Enumeration enum2 = daughter.GrandDaughters.elements();enum2.hasMoreElements();)
			{
				GrandDaughter grandDaughter = (GrandDaughter) enum2.nextElement();

				if (grandDaughter.rc.inside(x,y))
				{
					BrowserFrame_.setCursor(BrowserFrame_.HAND_CURSOR); 
					return true;
				}
			}
		}

		if (theMother.rc.inside(x,y))
		{
			BrowserFrame_.setCursor(BrowserFrame_.HAND_CURSOR);
			return true;
		}

		// One single daughter only
		Daughter soleDaughter = (Daughter) theMother.Daughters.elementAt(0);
		
		if (soleDaughter.rc.inside(x,y)) 
		{
			BrowserFrame_.setCursor(BrowserFrame_.HAND_CURSOR);
			return true;
		}

		BrowserFrame_.setCursor(BrowserFrame_.DEFAULT_CURSOR);
		return true;
	}

  public synchronized boolean mouseUp(Event evt, int x, int y) 
	{
		for (Enumeration enum = theMother.Daughters.elements();enum.hasMoreElements();)
		{
			Daughter daughter = (Daughter) enum.nextElement();

			for (Enumeration enum2 = daughter.GrandDaughters.elements();enum2.hasMoreElements();)
			{
				GrandDaughter grandDaughter = (GrandDaughter) enum2.nextElement();

				if (grandDaughter.pushed)
				{
					grandDaughter.pushed = false;
					
					try
					{
						URL metaURL = new URL(grandDaughter.theURL);
						URL bareUnitURL = new URL(graphObj.meta2bare(grandDaughter.theURL));

						if (grandDaughter.hasContent)
						{
							graphObj.getAppletContext().showDocument(bareUnitURL,"vhlk");
						}
						else
						{
							URL logoURL = new URL(graphObj.KHSRLogopage);
							graphObj.getAppletContext().showDocument(logoURL,"vhlk"); 
						}
						
						if (!grandDaughter.isTerminal)
						{
							graphObj.CurrentDeepness++;
							graphObj.reInit(metaURL,grandDaughter.label,grandDaughter.theURL,grandDaughter.hasContent);
						}
					}
					catch (MalformedURLException e)
					{
						troubleShooting("MalformedURLException beim öffnen von " + grandDaughter.theURL);
					}
				}
			}
		}

		if (theMother.pushed)
		{
			theMother.pushed = false;

			try
			{
				URL metaURL = new URL(theMother.theURL);
				URL bareUnitURL = new URL(graphObj.meta2bare(theMother.theURL));
				
				if (0 == theMother.label.compareTo("?")) // Special case 
				{
					graphObj.getAppletContext().showDocument(metaURL,"vhlk");
				}
				else if (0 == theMother.label.compareTo(graphObj.getParameter("initiallabel")))
				{
					graphObj.CurrentDeepness--;
					URL accessURL = new URL(graphObj.TraditionalAccessToEntryPage.toString());
					graphObj.getAppletContext().showDocument(accessURL,"vhlk");
					graphObj.reInit(metaURL,theMother.label,theMother.theURL,true);
				}
				else
				{
					graphObj.CurrentDeepness--;
					URL logoURL = new URL(graphObj.KHSRLogopage);
					graphObj.getAppletContext().showDocument(logoURL,"vhlk");
					graphObj.reInit(metaURL,theMother.label,theMother.theURL,false);
				}
			}
			catch (MalformedURLException e)
			{
				troubleShooting("MalformedURLException beim öffnen von " + theMother.theURL);
			}
		}

		// Again using my knowledge, that there is only one daughter...
		Daughter soleDaughter = (Daughter) theMother.Daughters.elementAt(0);
		
		if (soleDaughter.pushed) 
		{
			soleDaughter.pushed = false;
			
			// Display alraedy ok, just load daughter
			try
			{
				if (soleDaughter.hasContent)
				{
					if (0 == soleDaughter.label.compareTo(graphObj.getParameter("initiallabel")))
					{
						URL accessURL = new URL(graphObj.TraditionalAccessToEntryPage.toString());
						graphObj.getAppletContext().showDocument(accessURL,"vhlk");
					}
					else
					{
						URL bareUnitURL = new URL(graphObj.meta2bare(soleDaughter.theURL));
						graphObj.getAppletContext().showDocument(bareUnitURL,"vhlk");
					}
				}
				else
				{
					URL logoURL = new URL(graphObj.KHSRLogopage);
					graphObj.getAppletContext().showDocument(logoURL,"vhlk");
				}
			}
			catch (MalformedURLException e)
			{
				troubleShooting("MalformedURLException beim öffnen von " + soleDaughter.theURL);
			}
		}

		return true;
	}

  public void start() 
	{
		relaxer = new Thread(this);
		relaxer.start();

		// Get handle to browser frame; this is a little tricky, I must admit; explanation at http://smapp.gis.de
		Component ParentComponent;
		ParentComponent = getParent();
		
		while (ParentComponent != null && !(ParentComponent instanceof Frame)) 
		{      
			ParentComponent = ParentComponent.getParent();   
		}

		BrowserFrame_ = (Frame) ParentComponent;         
  }
  
	public void stop() 
	{
		relaxer.stop();
  }

	public void troubleShooting(String whatsWrong)
	{
		emergencyStringBuf.setLength(0);
		emergencyStringBuf.append(whatsWrong);
		fatalError = true;
		repaint();
	}
}

public class KHSClient extends Applet 
{
  GraphPanel panel;
	StringBuffer TraditionalAccessToEntryPage = new StringBuffer();  
	StringBuffer StructureOnlyUnitsCallThisURL = new StringBuffer(); 
	String KHSRLogopage = new String("http://pc5939.psychologie.uni-regensburg.de:8008/realizeKHSClient/KHSRLogo.htm");
	int CurrentDeepness = 0;

  public void init() 
	{
		Vector daughtersNames = new Vector(10,5);
		setLayout(new BorderLayout());

		panel = new GraphPanel(this);
		add("Center", panel);
		//Panel p = new Panel(); This is how you would add panels
		//add("South", p);

		MediaTracker mediaTracker = new MediaTracker(this);
		URL codeBase = getCodeBase();
		panel.contentSymbol = getImage(codeBase,"ContentSymbol.gif");
		mediaTracker.addImage(panel.contentSymbol,0);
		panel.upperSymbol = getImage(codeBase,"UpSymbol.gif");
		mediaTracker.addImage(panel.upperSymbol,0);
		panel.downerSymbol = getImage(codeBase,"DownSymbol.gif");
		mediaTracker.addImage(panel.downerSymbol,0);

		try
		{
			mediaTracker.waitForAll();
		}
		catch (InterruptedException e)
		{
			panel.troubleShooting("Media tracker exception trying to load symbols");
		}
		
		panel.leveledColors[0] = new Color(135,255,255);
	  panel.leveledColors[1] = new Color(150,240,255);
	  panel.leveledColors[2] = new Color(165,225,255);
	  panel.leveledColors[3] = new Color(180,210,255);
	  panel.leveledColors[4] = new Color(195,195,255);
	  panel.leveledColors[5] = new Color(210,180,255);
	  panel.leveledColors[6] = new Color(225,165,255);
	  panel.leveledColors[7] = new Color(240,150,255);
	  panel.leveledColors[8] = new Color(255,135,255);

		String serverandport = getParameter("serverandport");
		String hypertext = getParameter("hypertext");
		String initialnode = getParameter("initialnode");
		String initiallabel = getParameter("initiallabel");
		String structuremsg = getParameter("structuremsg");

		try 
		{
			TraditionalAccessToEntryPage.append(serverandport + "/khs/access/" + hypertext + "/unit/" + initialnode);
			StructureOnlyUnitsCallThisURL.append(serverandport + "/realizeKHSClient/" + structuremsg);
			URL iniURL = new URL(serverandport + "/walterskhs/meta/" + hypertext + "/unit/" + initialnode);
			BufferedInputStream in = new BufferedInputStream(iniURL.openStream());
			
			eatUninterestingStuff(in); // Consume stuff before hierarchy info
			getMotherOfMine(in); // Consume hierarchy info

			panel.theMother.label = "?";	// Because we are doing the initial request
			panel.theMother.theURL = "http://pc5939.psychologie.uni-regensburg.de:8008/realizeKHSClient/KHSQuestionmark.htm"; // Via FileResponder
			panel.theMother.hasContent = true; // The text of KHSQuestionmark.htm
			
			// This would work for multiple daughters, too
			if (daughtersNames.contains(initiallabel))
			{
				// Initially impossible 
			}
			else // Make new daughter 
			{
				Daughter daughter = new Daughter();
				daughter.label = initiallabel;
				daughter.theURL = TraditionalAccessToEntryPage.toString(); 
				daughter.hasContent = true; // Open door to traditinal KHS  
				daughter.distance2root = CurrentDeepness;
				daughter.selected = true;
				panel.theMother.Daughters.addElement(daughter);
				daughtersNames.addElement(daughter.label);
			}

			// This is outlined to work with multiple daugthers (not supported at the moment)
			for (Enumeration enum = panel.theMother.Daughters.elements();enum.hasMoreElements();)
			{
				Daughter daughterTmp = (Daughter) enum.nextElement();

				if (0 == daughterTmp.label.compareTo(initiallabel)) // We got her 
				{
					// Actually, there is only one daughter, so I simlpy append all granddaughters here
					while (true) 
					{
						String aChildOfMine = new String(getNextChildOfMine(in));
						int cmp = aChildOfMine.compareTo("UNDEFINED");
			
						if (cmp == 0) // No more granddaughters
						{
							break;
						}
						else
						{
							GrandDaughter grandDaughter = new GrandDaughter();
							
							grandDaughter.label =	labelSubString(aChildOfMine);
							grandDaughter.theURL = access2meta(urlSubString(aChildOfMine));
							grandDaughter.hasContent = infoSubStringIsTerminal(aChildOfMine);
							grandDaughter.isTerminal = infoSubStringIsTerminal(aChildOfMine);
							daughterTmp.GrandDaughters.addElement(grandDaughter); 
						}
					}
				} 
			}

			in.close();
		}
		catch (MalformedURLException e)
		{
			panel.troubleShooting("MalformedURLException in method init()");
		}
		catch (IOException e)
		{
			panel.troubleShooting("IOException in method init()");
		}
		catch (SecurityException e)
		{
			panel.troubleShooting("SecurityException in method init()");
		}

		setBackground(panel.backgroundColor);
		panel.repaint();
  }

  public void reInit(URL newDaughterURL,String dauLabel,String dauURL,boolean dauHasContent) 
	{
		Vector daughtersNames = new Vector(10,5);

		// Flush old context information
		for (Enumeration enum = panel.theMother.Daughters.elements();enum.hasMoreElements();)
		{
			Daughter daughter = (Daughter) enum.nextElement();
			daughter.GrandDaughters.removeAllElements(); 
		}

		panel.theMother.Daughters.removeAllElements();
		
		// Parse context information from URL (new daughter node)
		try 
		{
			BufferedInputStream in = new BufferedInputStream(newDaughterURL.openStream());
			eatUninterestingStuff(in);

			// Read mother
			String motherOfMine = getMotherOfMine(in);; 

			panel.theMother.label = labelSubString(motherOfMine);
			panel.theMother.theURL = access2meta(urlSubString(motherOfMine));
			panel.theMother.hasContent = false;
			panel.theMother.isTerminal = infoSubStringIsTerminal(motherOfMine);
			panel.theMother.selected = false;

			if (panel.theMother.label.compareTo(getParameter("initiallabel")) == 0) // Special case
			{
				panel.theMother.hasContent = true;
			}

			if (dauLabel.compareTo(getParameter("initiallabel")) == 0) // It's the root doc, so...
			{
				panel.theMother.label = "?";
				panel.theMother.theURL = "http://pc5939.psychologie.uni-regensburg.de:8008/realizeKHSClient/KHSQuestionmark.htm";
				panel.theMother.hasContent = true;
				panel.theMother.isTerminal = false;
				panel.theMother.selected = false;
			}

			// Configure daughter; this is outlined to work with multiple daugthers (not supported at the moment)
			if (daughtersNames.contains(dauLabel))
			{
				// Do nothing, daughters must not have identical names
			}
			else // Make new daughter
			{
				Daughter daughter = new Daughter();
				daughter.label = new String(dauLabel);
				daughter.theURL = new String(dauURL);
				daughter.hasContent = dauHasContent;
				daughter.isTerminal = false;
				daughter.distance2root = CurrentDeepness;
				daughter.selected = true;
				panel.theMother.Daughters.addElement(daughter);
				// Remember her name
				daughtersNames.addElement(daughter.label);
			}

			// This is outlined to work with multiple daugthers (not supported at the moment)
			for (Enumeration enum = panel.theMother.Daughters.elements();enum.hasMoreElements();)
			{
				Daughter daughterTmp = (Daughter) enum.nextElement();

				if (0 == daughterTmp.label.compareTo(dauLabel)) // We got her
				{
					// Actually, there is only one daughter, so I simlpy append all granddaughters here
					while (true) 
					{
						String aChildOfMine = new String(getNextChildOfMine(in));
						int cmp = aChildOfMine.compareTo("UNDEFINED");
			
						if (cmp == 0) // No more granddaughters
						{
							break;
						}
						else
						{
							GrandDaughter grandDaughter = new GrandDaughter();
							
							grandDaughter.label =	labelSubString(aChildOfMine);
							grandDaughter.theURL = access2meta(urlSubString(aChildOfMine));
							grandDaughter.hasContent = infoSubStringIsTerminal(aChildOfMine);
							grandDaughter.isTerminal = infoSubStringIsTerminal(aChildOfMine);
							daughterTmp.GrandDaughters.addElement(grandDaughter); 
						}
					} 
				}
			}

			in.close();
			panel.newLayout = true;
			panel.repaint();
		}
		catch (MalformedURLException e)
		{
			panel.troubleShooting("MalformedURLException in method reInit()");
		}
		catch (IOException e)
		{
			panel.troubleShooting("IOException in method reInit()");
		}
		catch (SecurityException e)
		{
			panel.troubleShooting("SecurityException in method reInit()");
		}
	}

	
	private void eatUninterestingStuff(InputStream in)
	{
		int b;
		char sniff4it[] = {'I','D','=','"','H','I','E','R','A','R','C','H','Y','"','>'};
		int cntr = -1;
		boolean harkening = false;

		try
		{
			while ((b = in.read()) != -1)
			{
				if (!harkening && (char)b == sniff4it[0]) 	
				{
					cntr = 0;
					harkening = true;
					continue;
				}
				
				if (harkening)
				{
					cntr++;

					if ((char)b == sniff4it[cntr])
					{
						if ((char)b == '>')
						{
							return;
						}
						else
						{
							continue;
						}
					}
					else
					{
						cntr = -1;
						harkening = false;
					}
				}
			}
		}
		catch (Exception e)
		{
			panel.troubleShooting("Error: eatUninterestingStuff read failure");
		}
	}
	
	private String getMotherOfMine(InputStream in)
	{
		int b;
		StringBuffer hierBuf = new StringBuffer(512);
		char sniff4it[] = {'/','D','I','V','>'};
		int cntr = -1;
		boolean harkening = false;
		
		try
		{
			while ((b = in.read()) != -1)
			{
				hierBuf.append((char)b);
				
				if (!harkening && (char)b == sniff4it[0]) 	
				{
					cntr = 0;
					harkening = true;
					continue;
				}
				
				if (harkening)
				{
					cntr++;

					if ((char)b == sniff4it[cntr])
					{
						if ((char)b == '>')
						{
							break;
						}
						else
						{
							continue;
						}
					}
					else
					{
						cntr = -1;
						harkening = false;
					}
				}
			}
		}
		catch (IOException e)
		{
			panel.troubleShooting("Error: getMotherUnitLabel read failure");
		}
	
		// hierBuf now contains the hierarchy information, address and name of parent
		String debug = new String(hierBuf.toString());
		StringTokenizer st = new StringTokenizer(hierBuf.toString());

		StringBuffer garbage = new StringBuffer();
		StringBuffer address = new StringBuffer();
		StringBuffer name = new StringBuffer();

		while (true)
		{
			garbage.setLength(0);
			garbage.append(st.nextToken("\""));
			address.setLength(0);
			address.append(st.nextToken("\""));
			garbage.setLength(0);
			garbage.append(st.nextToken("\""));
			garbage.setLength(0);
			garbage.append(st.nextToken("\""));
			name.setLength(0);
			name.append(st.nextToken("<"));

			if (st.countTokens() <= 2)
				break;
		}

		String pureName = (name.toString()).substring(2);			
		return address.toString() + "|" + pureName +"$" + "STRUCTUREONLY";
	}

	private String getNextChildOfMine(BufferedInputStream in)	
	{
		StringBuffer candidate = new StringBuffer();
		int b;
		boolean harkening = false;
		boolean somethingFound = false;
		char sniff4it[] = {'<','/','A','>'};
		int cntr = -1;

		try
		{
			while ((b = in.read()) != -1)
			{
				candidate.append((char)b);
				
				if (!harkening && (char)b == sniff4it[0]) 	
				{
					cntr = 0;
					harkening = true;
					continue;
				}
				
				if (harkening)
				{
					cntr++;

					if ((char)b == sniff4it[cntr])
					{
						if ((char)b == '>')
						{
							somethingFound = true;
							break;
						}
						else
						{
							continue;
						}
					}
					else
					{
						cntr = -1;
						harkening = false;
					}
				}
			}
		}
		catch (Exception e)
		{
			panel.troubleShooting("Error: getNextChildOfMine read failure");
		}

		if (somethingFound == false) // Past last node
		{
			return "UNDEFINED";
		}
		else // Figure out child description from candidate
		{
			// Cut away leading stuff before http://.....
			String strStep1 = candidate.toString();
			int idx = strStep1.indexOf("http://");
			String strStep2 = strStep1.substring(idx);
			int idxHTTPend = strStep2.indexOf("\""); 
			StringBuffer resultURL = new StringBuffer(strStep2.substring(0,idxHTTPend)); // Got URL
			int idxNameBegin = strStep2.indexOf("return true\">") + 13;  
			int idxNameEnd = strStep2.indexOf("</A>");
			String resultName = strStep2.substring(idxNameBegin,idxNameEnd); // Got Name

			StringBuffer resultInfo = new StringBuffer();
			StringBuffer pureName = new StringBuffer(); 
			int idxUglyTail;
			
			if ((idxUglyTail = (resultName.toString()).indexOf("...")) == -1)
			{
				pureName.append(resultName);
				resultInfo.append("TERMINALTEXT");
			}
			else
			{
				pureName.append(resultName.substring(0,idxUglyTail));
				resultInfo.append("STRUCTUREONLY");
			} // Got Unit Type
			
			return resultURL + "|" + pureName + "$" + resultInfo;
		}
	}

	private String labelSubString(String combinedUnitDescription)
	{
		int idxBegin = combinedUnitDescription.indexOf("|");
		int idxEnd = combinedUnitDescription.indexOf("$");

		// Special characters of the german language must be deHTMLed
		String replacePatterns[] = {"&Auml;","&auml;","&Ouml;","&ouml;","&Uuml;","&uuml;"}; 
		char replaceChars[] = {'Ä','ä','Ö','ö','Ü','ü'};
		String raw = new String(combinedUnitDescription.substring(idxBegin+1,idxEnd));
		StringBuffer parseMe = new StringBuffer(raw);
		StringBuffer cooked = new StringBuffer();
		int idxb;
		int idxe;

		for (int i = 0;i < 6;i++)
		{
			idxb = idxe = 0;
			cooked.setLength(0);
			
			while ((idxe = (parseMe.toString()).indexOf(replacePatterns[i])) != -1)
			{
				cooked.append((parseMe.toString()).substring(idxb,idxe));
				cooked.append(replaceChars[i]);
				idxb = idxe + 6;
				String nextPart = new String((parseMe.toString()).substring(idxb));
				parseMe.setLength(0);
				parseMe.append(nextPart);
			}

			String parseMeTail = new String(parseMe.toString());
			parseMe.setLength(0);
			parseMe.append(cooked.toString());
			parseMe.append(parseMeTail);
		}

		return parseMe.toString();
	}

	private String urlSubString(String combinedUnitDescription)
	{
		int idxEnd = combinedUnitDescription.indexOf("|");
		return combinedUnitDescription.substring(0,idxEnd);
	}

	private boolean infoSubStringIsTerminal(String combinedUnitDescription)
	{
		if (-1 != combinedUnitDescription.indexOf("$TERMINALTEXT"))
			return true;
		else
			return false;
	}

	private String access2meta(String access)
	{
		int cut = access.indexOf("?sessionKey");
		String prepared = access.substring(0,cut);
		int idxBeginChangePart = prepared.indexOf("/khs/access/");
		int idxEndChangePart = idxBeginChangePart + 12;
		String serverandport = prepared.substring(0,idxBeginChangePart);
		String unchangedTail = prepared.substring(idxEndChangePart);

		return serverandport + "/walterskhs/meta/" + unchangedTail;
	}

	public String meta2bare(String meta)
	{
		int idxBeginChangePart = meta.indexOf("/walterskhs/meta/");

		if (idxBeginChangePart == -1)
		{
			return meta; // Leave alone special URLs
		}

		int idxEndChangePart = idxBeginChangePart + 16;
		String serverandport = meta.substring(0,idxBeginChangePart);
		String unchangedTail = meta.substring(idxEndChangePart);

		return serverandport + "/walterskhs/access/" + unchangedTail;
	}
	
	public void start() 
	{
		panel.start();
  }
  
	public void stop() 
	{
		panel.stop();
  }
}