package vektorzeichnen;

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

public class Applet1 extends Applet {
  boolean isStandalone = false;
  /**Parameterwert holen*/
  public String getParameter(String key, String def) {
    return isStandalone ? System.getProperty(key, def) :
      (getParameter(key) != null ? getParameter(key) : def);
  }

  /**Das Applet konstruieren*/
  public Applet1() {
  }
  /**Das Applet initialisieren*/
  public void init() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  /**Initialisierung der Komponenten*/
  private void jbInit() throws Exception {
    button1.setLabel("grösser");
    button1.setBounds(new Rectangle(297, 31, 85, 27));
    button1.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button1_actionPerformed(e);
      }
    });
    this.setLayout(null);
    button2.setLabel("kleiner");
    button2.setBounds(new Rectangle(301, 69, 85, 26));
    button2.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        button2_actionPerformed(e);
      }
    });
    this.add(button1, null);
    this.add(button2, null);
  }
  Button button1 = new Button();
  Button button2 = new Button();

  int x[]={0,1,1,0,-2,2,-2,+2}; // Folge von x-Werten
  int y[]={2,1,-1,-2,0,2,0,-2}; // Folge von y-Werten
  int anzahl=8;  // 8 Vektoren
  int xnull= 20, ynull=200;  // Nullposition
  int zoom = 40;             // Vergroesserungsfaktor

  public void paint (Graphics g){
    int i; // Indexvariable
    int oldx,oldy,xi,yi;  // Hilfsvariablen
    g.setColor(Color.black);
    oldx=xnull;  // am Nullpunkt anfangen
    oldy=ynull;
    for (i=0; i<anzahl; i++){ // alle Vektoren zeichnen
      xi=oldx+x[i]*zoom;  // neue x-Position berechnen
      yi=oldy-y[i]*zoom;  // neue y-Position berechnen
      g.drawLine(oldx,oldy,xi,yi);// Linie zeichnen
      oldx=xi;  // x-Position merken
      oldy=yi;  // y-Position merken
    }
  }
  void button1_actionPerformed(ActionEvent e) {
    zoom=zoom+10; // vergroessern
    repaint();    // neu zeichnen
  }
  void button2_actionPerformed(ActionEvent e) {
    zoom=zoom-10; // verkleinern
    repaint();    // neu zeichnen
  }
}