Repaint Java - I've read many questions, but still not working

Question

Like in a topic, I've readed the most of all solutions for repaint() but for my code their are not working. I'm a begginer so forgive me a mess in my code..

class View.java

public class View extends JFrame{
public void make(){
    setSize(640,480);
    setVisible(true);
    setTitle("Parking");
}

double x_ = MyFrame.x;
double y_ = MyFrame.y;
double odchylenie_ = MyFrame.odchylenie;
int szerokosc = 50;
int wysokosc = 30;

   public void paint(Graphics g){
       Rectangle2D rect = new Rectangle2D.Double(-szerokosc / 2., -wysokosc / 2.,                    szerokosc, wysokosc);
       AffineTransform transform = new AffineTransform();
       transform.translate(x_, y_);
       transform.rotate(Math.toRadians(odchylenie_));
       Shape rotatedRect = transform.createTransformedShape(rect);
       Graphics2D g2 = (Graphics2D)g;
       g2.draw(rotatedRect);
}

All I want to do to re-paint this rotatedRect with new values of x,y and odchylenie (sorry for polish variable names).

I'm calculating new variable values and using Jbutton to redraw it. Here is my MyFrame.class

public class MyFrame extends javax.swing.JFrame {

static double x,y,odchylenie,kat;

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        View v = new View();
        v.make();
        Fuzzy f = new Fuzzy();
        kat = f.wyjscie(x, odchylenie);
        jLabel5.setText("Kąt: " + Double.toString(kat));
        odchylenie = Fuzzy.wyliczOdchylenie(odchylenie,kat);
        jLabel8.setText("Nowe odchylenie: " + Double.toString(odchylenie));  
        x = Fuzzy.wyliczX(x, 10, kat,odchylenie);
        jLabel6.setText("Nowy x: " + Double.toString(x));
        y = Fuzzy.wyliczY(y,x, 10, kat,odchylenie);
        jLabel7.setText("Nowy y: " + Double.toString(y));
        v.repaint(); //Not works
   }

Instead of doing repaint(), the new window appears, and old one stays... I have tried to declare View v outside the button function body, but it not worked too(nothing is painting).

1) For better help sooner, post an [MCVE](http://stackoverflow.com/help/mcve) (Minimal Complete and Verifiable Example). 2) See [The Use of Multiple JFrames, Good/Bad Practice?](http://stackoverflow.com/a/9554657/418556) 3) *"I've read many questions.."* Link to 5 of them. You are making mistakes in the current codes and I would hope at least one of those 5 covers each of the mistakes. — Andrew Thompson, May 24 '14 at 02:04

score 2 · Answer 1 · answered May 23 '14 at 18:53

2

Whenever you override one of the paint() methods, you need to make a call to the super's method:

public void paint(Graphics g) {
    super.paint(g);
    // your code goes here
}

Further, you should really be using paintComponent(), not paint().

public void paintComponent(Graphics g) {
    super.paintComponent(g);
    // your code goes here
}

answered May 23 '14 at 18:53

martinez314

12,162
5
36
63

And also i've forget to say i've tried this too... the window only changes color from white to grey... – soncrash May 23 '14 at 18:55

Julián Chamalé · Answer 2 · 2014-05-23T19:04:49.147

1

Instead of using paint, use paintComponent:

public void paintComponent(Graphics g){
       super.paintComponent(g);
       Rectangle2D rect = new Rectangle2D.Double(-szerokosc / 2., -wysokosc / 2.,                    szerokosc, wysokosc);
       AffineTransform transform = new AffineTransform();
       transform.translate(x_, y_);
       transform.rotate(Math.toRadians(odchylenie_));
       Shape rotatedRect = transform.createTransformedShape(rect);
       Graphics2D g2 = (Graphics2D)g;
       g2.draw(rotatedRect);
}

edited May 23 '14 at 19:04

answered May 23 '14 at 18:51

Julián Chamalé

607
11
23

Does this answer the question or is it a design suggestion? – Anubian Noob May 23 '14 at 18:52
I'm sorry I've forget to say that I've tried this too. When I used paintComponent the Rectangle did not appear (only empty window) – soncrash May 23 '14 at 18:54
Did you call `super.paintComponents`? – Julián Chamalé May 23 '14 at 18:56
@System.exit Did you mean `paintComponent()`? `paintComponents()` (note the 's') is generally not overridden. – martinez314 May 23 '14 at 18:57
yes i called super.paintComponents(g) only window appear with no rectangle – soncrash May 23 '14 at 18:58
@whiskeyspider I made a mistake. I retract, without the 's'. Sorry for the confusion. – Julián Chamalé May 23 '14 at 19:00
when i'm trying to call super.paintComponent(g) theres a Cannot find symbol error – soncrash May 23 '14 at 19:02
@soncrash It is because I thought as a `JPanel`... Try to create a `JPanel` and `setContentPane` in your `View`. – Julián Chamalé May 23 '14 at 19:08
So my View should be JPanel instead of JFrame? public class View extends JPanel{ – soncrash May 23 '14 at 19:20
Yes, and then put it into a `JFrame`, as in `make()`. – Julián Chamalé May 23 '14 at 19:25
@System.exit but I can't put `setContentPane()` into make().. - cannot find sympol – soncrash May 23 '14 at 19:28
`setContentPane` it's an attribute of `JFrame`. In your container frame. – Julián Chamalé May 23 '14 at 19:33

Repaint Java - I've read many questions, but still not working

2 Answers2