当我调用repaint（）时，没有执行Paint（）方法

Question

I´m having some issues when trying to call the paint method with the instruction repaint() . At first, when the program executes the code included in the constructor, the paint method is executed. However, when I use the instruction repaint() , which is executed when I press the enter key, the content of method paint is not executed. I've seen other questions in SO that seemed similar to mine, but I haven't found the key for solving the problem.

The code (The call of repaint is done in the method calcularTrayectoria() )

package elementosJuego;

    import elementosJuego.paneles.PanelCanon;
    import elementosJuego.paneles.PanelMapaCanon;
    import java.awt.Color;
    import java.awt.Dimension;
    import java.awt.FlowLayout;
    import java.awt.Graphics;
    import java.awt.Graphics2D;
    import java.awt.GridLayout;
import java.awt.Image;
    import java.awt.Rectangle;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.awt.event.KeyAdapter;
    import java.awt.event.KeyEvent;
    import javax.swing.*;
    import javax.swing.plaf.basic.BasicProgressBarUI;

        /**
         *
         * @author ignacioaranguren
         */
        public class Juego extends JFrame {
            private Casilla[][] mapa;
            private JPanel contenedorTiempo, contenedorVidas,contenedorBarra;
            private PanelMapaCanon contenedorMapaCanon;
            private PanelCanon contenedorCanon;
            private Dimension d1, d2, d3, d4, d5;
            private double anguloRotacion = Math.PI/2, anguloMin = 0.656173986, anguloMax = 2.485418668;
            private double vX, vY, x1, x2;
            private JProgressBar barra;
            private ActionListener ac ;
            private Timer t;
            private int progreso = 0;
            private boolean flag = false, flagBala = false;


            public Juego(){

                setLayout(null);

                d1 = new Dimension(646, 699);
                contenedorMapaCanon = new PanelMapaCanon(d1);
                contenedorMapaCanon.setBounds(0, 0, 646, 699);

                barra = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);


                barra.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0), 2, true));
                barra.setUI(new BasicProgressBarUI(){
                    @Override
                    protected void paintDeterminate(Graphics g, JComponent c) {
                        Graphics2D g2d = (Graphics2D)g;
                        int ancho = barra.getWidth();
                        int alto = barra.getHeight();

                        int espacioAncho = ancho ;
                        int espacioAlto = alto ;
                        barra.setPreferredSize( new Dimension(200,40));
                        double porcentajeProgres = barra.getPercentComplete();

                        espacioAncho = (int)(espacioAncho * porcentajeProgres);
                        if(porcentajeProgres <= 0.25){
                            g2d.setColor(Color.GREEN);
                        }else if( porcentajeProgres > 0.25 && porcentajeProgres <= 0.5){
                            g2d.setColor(Color.yellow);
                        }else if( porcentajeProgres > 0.5 && porcentajeProgres <= 0.75){
                            g2d.setColor(Color.orange);
                        }else{
                            g2d.setColor(Color.red);
                        }
                        Rectangle rec1 = new Rectangle(0,0, espacioAncho, espacioAlto);
                        g2d.fill(rec1);
                    }

                 });
                 ac = new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        if(flag == false){
                        progreso = progreso + 1;
                        if(progreso == 99){
                            flag = true;
                        }
                        }else{
                            progreso = progreso - 1;
                            if(progreso == 1){
                                flag = false;
                            }
                        }
                        barra.setValue(progreso);
                    }

                };
                t = new Timer(20, ac);
                t.start();
                d2 = new Dimension(646, 120);
                contenedorCanon = new PanelCanon(d2);
                contenedorCanon.setLayout(new FlowLayout(FlowLayout.RIGHT));

                d4 = new Dimension(100, 100);
                contenedorVidas = new JPanel();
                contenedorVidas.setBackground(Color.red);
                contenedorVidas.setSize(d4);



                d5 = new Dimension(100, 100);
                contenedorTiempo = new JPanel();
                contenedorTiempo.setBackground(Color.blue);
                contenedorTiempo.setSize(d5);
                addKeyListener(new KeyAdapter() {
                    @Override
                    public void keyPressed(KeyEvent evento) {
                        switch (evento.getKeyCode()) {
                            case KeyEvent.VK_LEFT:
                                if(anguloRotacion > anguloMin && anguloRotacion < anguloMax ){
                                    anguloRotacion = anguloRotacion + 0.05;
                                    contenedorCanon.setAngulo(anguloRotacion);
                                    contenedorCanon.repaint();
                                }
                                break;
                            case KeyEvent.VK_RIGHT:
                                if(anguloRotacion > anguloMin && anguloRotacion < anguloMax){
                                    anguloRotacion = anguloRotacion - 0.05;
                                    contenedorCanon.setAngulo(anguloRotacion);
                                    contenedorCanon.repaint();
                                }
                                break;
                            case KeyEvent.VK_ENTER:
                                puntoIncialBala();
                                flagBala = true;
                                double i = 0.05;
                                while(i < 200){
                                    puntoIncialBala();
                                    calcularTrayectoria(i);
                                    i = i + 0.05;
                                }
                                break;
                        }
                       requestFocus();
                    }

                });
                add(contenedorMapaCanon);
                add(contenedorCanon);
                contenedorCanon.add(barra);
                setSize(900,900);

                setVisible(true);

            }

            private void puntoIncialBala(){
                if(anguloRotacion < Math.PI/2){
                    vX = 369 + Math.sin(anguloRotacion);
                    vY = 788 + Math.cos(anguloRotacion);
                }else{
                    vX = 369 - Math.sin(anguloRotacion);
                    vY = 788 - Math.cos(anguloRotacion);
                }
            }

            private void calcularTrayectoria(double gamma){

                 x1 = 335+contenedorCanon.getPuntoMedX()+ gamma * vX;
                 x2 = 700+contenedorCanon.getPuntoMedY()+ gamma * vY;
                 revalidate();
                 this.repaint();
            }

            @Override
            public void paint(Graphics g){
                Graphics g2d = (Graphics2D) g;
                contenedorCanon.setBounds(30, 700, 646, 120);
                contenedorCanon.paintComponent(g);
                contenedorMapaCanon.setBounds(0, 0, 676, 699);
                contenedorMapaCanon.paintComponent(g);
                Image img = new ImageIcon(getClass().getResource("/imagenes/BalaCanon.png")).getImage();
                if(flagBala == true)
                    g2d.drawImage(img, (int)x1, (int)x2, this); 

            }

            private void puntoFinalbala(){

            }
        }

Answer 1

JFrame is not a JComponent , it doesn't have a paintComponent or paint method you can override. Instead you could extend a JPanel and add it to the frame.

Your class doesn't extend from any Component capable of painting