Pourquoi ne dessine-t-il pas une courbe animée?

Question

Voici ma classe que j'ai trouvée sur Internet. C'était à l'origine une applet mais je ne veux pas l'utiliser comme une applet donc j'ai changé certaines méthodes (telles que init() à un constructeur).

Cependant, cela ne fonctionne pas. Pourriez vous m'aider s'il vous plait?

SignInFrame Cadre:

public class SignInFrame extends javax.swing.JFrame { 

Panel panel; 

/** Creates new form SignInFrame */ 
public SignInFrame() { 
    initComponents(); 
} 


public void init() { 
    getContentPane().add(panel = new Panel()); 

} 

public void start() { 
    panel.start(); 
} 

public void stop() { 
    panel.stop(); 
} 
public static void main(String args[]) { 
    java.awt.EventQueue.invokeLater(new Runnable() { 
     public void run() { 
      new SignInFrame().setVisible(true); 
     } 
    }); 
}} 

Dialog Panel:

package ClientGUI; 

import java.awt.BasicStroke; 
import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.GradientPaint; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.Paint; 
import java.awt.RenderingHints; 
import java.awt.geom.GeneralPath; 
import java.awt.image.BufferedImage; 

/** 
* 
* @author ICC 
*/ 

public class Panel extends javax.swing.JPanel implements Runnable{ 


private Thread thread; 
    private BufferedImage bimg; 
    private static final int NUMPTS = 6; 

    // solid line stoke 
    protected BasicStroke solid = new BasicStroke(10.0f, 
         BasicStroke.CAP_BUTT, BasicStroke.JOIN_ROUND); 
    // dashed line stroke 
    protected BasicStroke dashed = new BasicStroke(10.0f, 
     BasicStroke.CAP_BUTT, BasicStroke.JOIN_ROUND, 10, new float[] {5}, 0); 
    private float animpts[] = new float[NUMPTS * 2]; 
    private float deltas[] = new float[NUMPTS * 2]; 
    protected Paint fillPaint, drawPaint; 

    // indicates whether or not to fill shape 
    protected boolean doFill = true; 

    // indicates whether or not to draw shape 
    protected boolean doDraw = true; 
    protected GradientPaint gradient; 
    protected BasicStroke stroke; 


    public Panel() { 
     setBackground(Color.white); 
     gradient = new GradientPaint(0,0,Color.red,200,200,Color.yellow); 
     fillPaint = gradient; 
     drawPaint = Color.blue; 
     stroke = solid; 

    } 
      // generates new points for the path 
    public void animate(float[] pts, float[] deltas, int i, int limit) { 
     float newpt = pts[i] + deltas[i]; 
     if (newpt <= 0) { 
      newpt = -newpt; 
      deltas[i] = (float) (Math.random() * 4.0 + 2.0); 
     } else if (newpt >= (float) limit) { 
      newpt = 2.0f * limit - newpt; 
      deltas[i] = - (float) (Math.random() * 4.0 + 2.0); 
     } 
     pts[i] = newpt; 
    } 


    /* 
    * generates random points with the specified surface width 
    * and height for the path 
    */ 
    public void reset(int w, int h) { 
     for (int i = 0; i < animpts.length; i += 2) { 
      animpts[i + 0] = (float) (Math.random() * w); 
      animpts[i + 1] = (float) (Math.random() * h); 
      deltas[i + 0] = (float) (Math.random() * 6.0 + 4.0); 
      deltas[i + 1] = (float) (Math.random() * 6.0 + 4.0); 
      if (animpts[i + 0] > w/2.0f) { 
       deltas[i + 0] = -deltas[i + 0]; 
      } 
      if (animpts[i + 1] > h/2.0f) { 
       deltas[i + 1] = -deltas[i + 1]; 
      } 
     } 
     gradient = new GradientPaint(0,0,Color.red,w*.7f,h*.7f,Color.yellow); 
    } 


    // calls animate for every point in animpts 
    public void step(int w, int h) { 
     for (int i = 0; i < animpts.length; i += 2) { 
      animate(animpts, deltas, i + 0, w); 
      animate(animpts, deltas, i + 1, h); 
     } 
    } 


    // sets the points of the path and draws and fills the path 
    public void drawDemo(int w, int h, Graphics2D g2) { 
     float[] ctrlpts = animpts; 
     int len = ctrlpts.length; 
     float prevx = ctrlpts[len - 2]; 
     float prevy = ctrlpts[len - 1]; 
     float curx = ctrlpts[0]; 
     float cury = ctrlpts[1]; 
     float midx = (curx + prevx)/2.0f; 
     float midy = (cury + prevy)/2.0f; 
     GeneralPath gp = new GeneralPath(GeneralPath.WIND_NON_ZERO); 
     gp.moveTo(midx, midy); 
     for (int i = 2; i <= ctrlpts.length; i += 2) { 
      float x1 = (midx + curx)/2.0f; 
      float y1 = (midy + cury)/2.0f; 
      prevx = curx; 
      prevy = cury; 
      if (i < ctrlpts.length) { 
       curx = ctrlpts[i + 0]; 
       cury = ctrlpts[i + 1]; 
      } else { 
       curx = ctrlpts[0]; 
       cury = ctrlpts[1]; 
      } 
      midx = (curx + prevx)/2.0f; 
      midy = (cury + prevy)/2.0f; 
      float x2 = (prevx + midx)/2.0f; 
      float y2 = (prevy + midy)/2.0f; 
      gp.curveTo(x1, y1, x2, y2, midx, midy); 
     } 
     gp.closePath(); 
     if (doDraw) { 
      g2.setPaint(drawPaint); 
      g2.setStroke(stroke); 
      g2.draw(gp); 
     } 
     if (doFill) { 
      if (fillPaint instanceof GradientPaint) { 
       fillPaint = gradient; 
      } 
      g2.setPaint(fillPaint); 
      g2.fill(gp); 
     } 
    } 


    public Graphics2D createGraphics2D(int w, int h) { 
     Graphics2D g2 = null; 
     if (bimg == null || bimg.getWidth() != w || bimg.getHeight() != h) { 
      bimg = (BufferedImage) createImage(w, h); 
      reset(w, h); 
     } 
     g2 = bimg.createGraphics(); 
     g2.setBackground(getBackground()); 
     g2.clearRect(0, 0, w, h); 
     g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
          RenderingHints.VALUE_ANTIALIAS_ON); 
     return g2; 
    } 


    public void paint(Graphics g) { 
     Dimension d = getSize(); 
     step(d.width, d.height); 
     Graphics2D g2 = createGraphics2D(d.width, d.height); 
     drawDemo(d.width, d.height, g2); 
     g2.dispose(); 
     if (bimg != null) { 
      g.drawImage(bimg, 0, 0, this); 
     } 
    } 


    public void start() { 
     thread = new Thread(this); 
     thread.setPriority(Thread.MIN_PRIORITY); 
     thread.start(); 
    } 


    public synchronized void stop() { 
     thread = null; 
    } 


    public void run() { 
     Thread me = Thread.currentThread(); 
     while (thread == me) { 
      repaint(); 
      try { 
       Thread.sleep(10); 
      } catch (Exception e) { break; } 
     } 
     thread = null; 
    } 
    public static void main(String argv[]) { 
    SignInFrame n = new SignInFrame(); 

    n.start(); 
}} 

Answer 1

Dans votre constructeur SignInFrame, vous appelez initComponents(), mais cela n'existe pas. Je pense que vous voulez appeler init(). De plus, votre JFrame n'a pas de taille définie, quand j'ai lancé ceci sous Linux (Java 1.6), cela a fonctionné mais était minuscule, vous devriez ajouter un appel à setSize.

Essayez avec ces modifications:

public class SignInFrame extends javax.swing.JFrame { 

    Panel panel; 

    /** Creates new form SignInFrame */ 
    public SignInFrame() { 
     setSize (600,600); 
     init(); 
    } 


    public void init() { 
     getContentPane().add(panel = new Panel()); 
     start(); 
    } 

    public void start() { 
     panel.start(); 
    } 

    public void stop() { 
     panel.stop(); 
    } 

    public static void main(String args[]) { 
     java.awt.EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       new SignInFrame().setVisible(true); 
      } 
     }); 
    } 

}