Oprava zdrojáků v programu

[kami]

Mám napsané zdrojové kody programu, který má vykreslovat průběh zvolené matematické funkce. Hodnoty těchto parametrů se mají měnit dynamicky za běhu programu pomocí posuvníku jslider. Barva grafu by se měla taky měnit.
Ale program mě graf vykresluje špatně, a barvu nemění vůbec.Prosím o radu , kde mám v programu chybu!
Děkuji

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package zapocet;

import java.awt.Color;
import java.awt.Graphics;


/**
 *
 * @author 
 */


public class  funkce extends javax.swing.JApplet {
    double a,b,c;  //y=ax2+bx+c
    int s,v;   //sirka a vyska platna
    Graphics g;
    
   /** Initializes the applet funkce */
    @Override
    public void init() {
        try {
            java.awt.EventQueue.invokeAndWait(new Runnable() {
                public void run() {
                    initComponents();
                }
            });
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        a = 0.5;
        b = 5;
        c = 2;
        s = 300;
        v = 200;
      
        this.resize(s + 150, v + 100);
        platno.setSize(s, v);        
    }
    
    /** This method is called from within the init() method to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {
        
        jButton1 = new javax.swing.JButton();
        platno = new javax.swing.JPanel();
        sliderA = new javax.swing.JSlider();
        sliderB = new javax.swing.JSlider();
        sliderColor = new javax.swing.JSlider();
       
       platno.setBorder(javax.swing.BorderFactory.createEtchedBorder());

        javax.swing.GroupLayout platnoLayout = new javax.swing.GroupLayout(platno);
        platno.setLayout(platnoLayout);
        platnoLayout.setHorizontalGroup(
            platnoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 420, Short.MAX_VALUE)
        );
        platnoLayout.setVerticalGroup(
            platnoLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0,320, Short.MAX_VALUE)
        );

        jButton1.setText("vykresli!");
        jButton1.addMouseListener(new java.awt.event.MouseAdapter() {
            @Override
            public void mouseReleased(java.awt.event.MouseEvent evt) {
                jButton1MouseReleased(evt);
            }
        });

        sliderA.setMaximum(200);
        sliderA.addMouseListener(new java.awt.event.MouseAdapter() {
            @Override
            public void mouseReleased(java.awt.event.MouseEvent evt) {
                sliderAMouseReleased(evt);
            }
        });

        sliderB.setMaximum(300);
        sliderB.setValue(200);

        sliderColor.setMaximum(225);
        sliderColor.addMouseListener(new java.awt.event.MouseAdapter() {
            @Override
            public void mouseReleased(java.awt.event.MouseEvent evt) {
                sliderColorMouseReleased(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                        .addComponent(sliderB, 0, 0, Short.MAX_VALUE)
                        .addComponent(jButton1)
                        .addComponent(sliderA, javax.swing.GroupLayout.DEFAULT_SIZE, 80, Short.MAX_VALUE))
                    .addComponent(sliderColor, 0, 0, Short.MAX_VALUE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(platno, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(platno, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addContainerGap())
                    .addGroup(layout.createSequentialGroup()
                        .addComponent(jButton1)
                        .addGap(30, 30, 30)
                        .addComponent(sliderA, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addGap(36, 36, 36)
                        .addComponent(sliderB, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(120, 120, 120)
                        .addComponent(sliderColor, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(129, 129, 129))))
        );
    }// </editor-fold>//GEN-END:initComponents

    private void jButton1MouseReleased(java.awt.event.MouseEvent evt) {//GEN-FIRST:event_jButton1MouseReleased
        this.osy();
        int i;        
        g.setColor(barva);
        for(i=1;i<this.s;i++)
            g.drawLine(i,fx(i),i+1,fx(i+i));        
    }//GEN-LAST:event_jButton1MouseReleased

    private void sliderAMouseReleased(java.awt.event.MouseEvent evt) {//GEN-FIRST:event_sliderAMouseReleased
       jButton1MouseReleased(evt); 
    }//GEN-LAST:event_sliderAMouseReleased

    private void sliderColorMouseReleased(java.awt.event.MouseEvent evt) {//GEN-FIRST:event_sliderColorMouseReleased
       jButton1MouseReleased(evt);
    }//GEN-LAST:event_sliderColorMouseReleased

public void osy() {
        g=platno.getGraphics();
        s=platno.getSize().width;
        v=platno.getSize().height;
        g.clearRect(1,1,s-2,v-2);
        g.drawLine(0, v / 2, s, v / 2);
        g.drawLine(s / 2, 0, s / 2, v);
       
}
    public int fx(int x) {    // fx=ax2+bx+c
        a=sliderA.getValue()/100.0;
        return getY(a * getX(x) * getX(x) + b * getX(x)+ c);
    }

    public int getX(int x) {
        return x - s / 2;
    }

    public int getY(double y) {
        return v / 2 - (int) y;
    }        
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JPanel platno;
    private javax.swing.JSlider sliderA;
    private javax.swing.JSlider sliderB;
    private javax.swing.JSlider sliderColor;
    // End of variables declaration//GEN-END:variables 
        
    }

[Stefan Ihnat]

Tak hraní si s barvičkami mou nevyužívám , ale chybu tam nevidím, možná někdo kdo tyto knihovny využívá více ti poradí.

[B.A.X.O]

Mohl bys jinak používat tag Code tady na foru, kvůli přehlednosti