/***************************************************************/
/* Prof. Dr. Gregor Büchel                                     */
/* Source : Graph1a.java                                       */
/* Beispielprogramm für AWT-Methoden der GUI-Verarbeitung mit  */
/* Grafik. Verwendete Klassen: Panel, Graphics, Windowadapter  */
/* (Implementation der Schnittstelle WindowListener), Frame.   */
/* Stand: 22.06.2004                                           */
/***************************************************************/

import java.awt.*;
import java.awt.event.*;

class MyPa1 extends java.awt.Panel
{int a;
 public void paint(Graphics g)
 {int i, xi, yi;
  double xw, yw;
  String aw=new String();
  String bw=new String();
  switch(a)
  {case 1: g.drawLine(10,300,750,300);  /* x-Achse     */
           g.drawLine(300,10,300,550);  /* y-Achse     */
           g.drawLine(745,298,750,300); /* Spitze: x-Achse     */
           g.drawLine(745,302,750,300); /*  "    */
           g.drawLine(298,15,300,10);   /* Spitze: y-Achse     */
           g.drawLine(302,15,300,10);   /*  "    */
           g.drawString("y",280,20);    
           g.drawString("x",745,320); 
           for (i=-5; i<=5 ; i++)
           {/* xi = 300 + i* 50 ; yi = xi (Spezialfall) */
            if (i==0) continue;
            aw=aw.valueOf(i);
            xi=300+i*50;
            g.drawString(aw,xi,320);   /* Skalierung x-Achse */
            g.drawLine(xi,298,xi,302); /*       "            */
            g.drawString(aw,280,xi);   /* Skalierung y-Achse */
            g.drawLine(298,xi,302,xi); /*       "            */
           }
           break;
   case 2: g.drawOval(300,250,150,150);
           break;
   case 3: g.drawLine(10,300,750,300);  /* x-Achse     */
           g.drawLine(300,10,300,550);  /* y-Achse     */
           g.drawLine(745,298,750,300); /* Spitze: x-Achse     */
           g.drawLine(745,302,750,300); /*  "    */
           g.drawLine(298,15,300,10);   /* Spitze: y-Achse     */
           g.drawLine(302,15,300,10);   /*  "    */
           g.drawString("y",280,20);    
           g.drawString("x",745,320); 
           for (i=-5; i<=5 ; i++)
           {/* xi = 300 + i* 50 ; yi = xi (Spezialfall) */
            if (i==0) continue;
            aw=aw.valueOf(i);
            xi=300+i*50;
            g.drawString(aw,xi,320);   /* Skalierung x-Achse */
            g.drawLine(xi,298,xi,302); /*       "            */
            g.drawString(aw,280,xi);   /* Skalierung y-Achse */
            g.drawLine(298,xi,302,xi); /*       "            */
           }
           /* Polynom y=x*(x*x-4)                            */
           /* Berechnung: xi=i+300 ; yi=xi*(xi*xi-200)+300   */
           /* Intervall [-2.4,2.4] <=> -120<=i<=120          */
           for (i=-120; i<=120; i++)
           { xi=300+i;
             xw=i/50.;
             yw=xw*(xw*xw-4.);
             yi=(int)(yw*50.)+300; 
             g.drawLine(xi,yi,xi,yi);
           }
           break;
   case 4: g.drawLine(0,300,750,300);   /* x-Achse     */
           g.drawLine(300,10,300,550);  /* y-Achse     */
           g.drawLine(745,298,750,300); /* Spitze: x-Achse     */
           g.drawLine(745,302,750,300); /*  "    */
           g.drawLine(298,15,300,10);   /* Spitze: y-Achse     */
           g.drawLine(302,15,300,10);   /*  "    */
           g.drawString("y",280,20);    
           g.drawString("x",745,320); 
           for (i=-6; i<=6 ; i++)
           {/* Skalierung x-Achse */
            if (i==0) continue;
            aw=aw.valueOf(i);
            aw=aw+"PI/2";
            xi=300+i*50;
            g.drawString(aw,xi,320);   /* Skalierung x-Achse */
            g.drawLine(xi,298,xi,302); /*       "            */
           }
           for (i=-5; i<=5 ; i++)
           {/* Skalierung y-Achse  */
            if (i==0) continue;
            if (i%2==0) bw=bw.valueOf(i/2);
            else bw=" ";
            xi=300-i*50;
            g.drawString(bw,280,xi);   /* Skalierung y-Achse */
            g.drawLine(298,xi,302,xi); /*       "            */
           }
           /* Sinusfunktion:                                 */
           /* Berechnung: xi=i+300 ; yi=sin(xi)-300          */
           /* Intervall [-3PI,3PI] <=> -300<=i<=300          */
           for (i=-300; i<=300; i++)
           { xi=300+i;
             xw=(i/100.)*Math.PI;
             yw=Math.sin(xw);
             yi=(int)(yw*(-100.))+300; 
             g.drawLine(xi,yi,xi,yi);
           }
           break;
   default: g.drawString("Keine gültige Eingabe",30,30);
  } 
 }
}

class Fohr extends WindowAdapter
{public void windowClosing(WindowEvent e)
 {e.getWindow().setVisible(false);
  e.getWindow().dispose();
 }
}

class Graph1a {
 public static void main(String args[]) 
 {int i1=1, iz=0;
  String s1=new String("Koordinatensystem");
  String s2=new String();
  String s3=new String(" (");
  String s4=new String(")");
  MyPa1 p1;
  Fohr ew1=new Fohr();   
  Frame g1=new Frame("Koordinatensystem");
  p1=new MyPa1();      
  p1.a=1;
  g1.addWindowListener(ew1);
  g1.add(p1);
  g1.show();
  do
  {
   System.out.println("Gregors Grafik-Bastelstube arbeitet: ");
   System.out.println(" (1) Koordinatensystem");
   System.out.println(" (2) Ellipse");
   System.out.println(" (3) Kubisches Polynom");
   System.out.println(" (4) Trigonometrie");
   System.out.println(" (0) ENDE");
   i1=IO1.einint();
   switch(i1)
   {case 1: p1.a=1;
            iz=iz+1;
            s2=s2.valueOf(iz);
            g1.setTitle(s1.concat(s3.concat(s2.concat(s4))));
            p1.repaint();
            break;
    case 2: p1.a=2;
            g1.setTitle("Ellipse");
            p1.repaint();
            break;
    case 3: p1.a=3;
            g1.setTitle("Polynom y=x*(x*x-4)");
            p1.repaint();
            break;
    case 4: p1.a=4;
            g1.setTitle("Trigonometrie: y=sin(x)");
            p1.repaint();
            break;
    case 0: System.exit(0);
            break;
    default: p1.a=-999;
             g1.setTitle("Ungueltig!");
             p1.repaint();  
   }     
  } while (i1!=0); 
 }
}