Update Array of JLabels within a JPanel with GridLayout 5x5

Question

Basicaly i got a JPanel with a GridLayout 5x5 and each "square" as a JLabel with a number and a diferent background color, depending on the number that its there.

I need to update the panel everytime i click one of the buttons (except menu one) because it will change the array of array of ints that is where i get the numbers from to put in the labels.

My Question is how do i update every JLabel (including color) JFrame Layout

public static JPanel painel(){
    novo_jogo();
    // Painel Grelha
    JPanel grelha = new JPanel();
    GridLayout grid_grelha = new GridLayout(linhas, colunas, 3, 3);
    grelha.setLayout(grid_grelha);
    grelha.setOpaque(true);
    grelha.setSize(janela_x - 140, janela_y-140);
    grelha.setLocation(70, 20);
    grelha.setBackground(Color.GREEN);
    // criar JLabels
    for (int num = 0; num < linhas; num++){
        for (int num2 = 0; num2 < colunas; num2++){
            JLabel label = new JLabel();
            label.setText(String.valueOf(tabuleiro[num][num2]));
            label.setOpaque(true);
            label.setBackground(select_cor(tabuleiro[num][num2]));
            label.setHorizontalAlignment(SwingConstants.CENTER);
            grelha.add(label);
        }
    }
    return grelha;

this is the function that creates the entire panel in the proper grid etc... (This is also made in a diferent class that extends from the main one

public class Board extends Game{....}

my idea was to use the repaint() function to update only the panel with the grid JPanel grelha = Board.painel(); and then frame.getContentPane().add(grelha); later my idea was to update the grid (grelha) panel only but when i do this:

/* Main */
public static void main(String[] args){
    frame.setTitle("Jogo 2048 em Java"); // Titulo da janela
    frame.setSize(janela_x, janela_y); // Define o tamanho da janela
    frame.setLocationRelativeTo(null); // Centraliza a janela no ecrã
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    frame.setBackground(Color.WHITE);
    frame.setResizable(false); // Não deixa a janela ser aumentada
    // Painel Fundo
    JPanel fundo = new JPanel();
    fundo.setBackground(Color.WHITE);
    // Painel Botões
    JPanel botoes = new JPanel();
    GridLayout grid_botoes = new GridLayout(1, 5, 5, 5);
    botoes.setLayout(grid_botoes);
    botoes.setOpaque(true);
    botoes.setSize(360, 50);
    botoes.setLocation(70, 390);
    botoes.setBackground(Color.WHITE);
    JPanel grelha = Board.painel();
    // Botões e colocar no painel
    JButton init = new JButton("Init");
    JButton left = new JButton("Left");
    JButton down = new JButton("Down");
    JButton right = new JButton("Right");
    JButton menu = new JButton("Menu");
    botoes.add(init);
    botoes.add(left);
    botoes.add(down);
    botoes.add(right);
    botoes.add(menu);
    // Adicionar Panels à janela
    frame.getContentPane().add(botoes);
    frame.getContentPane().add(grelha);
    frame.getContentPane().add(fundo);
    frame.setVisible(true);
    // ActionListener dos botões
    ActionListener accao_botoes = new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            int n = -1;
            if (e.getSource().equals(init)) n = 0;
            else if (e.getSource().equals(left)) n = 1;
            else if (e.getSource().equals(down)) n = 2;
            else if (e.getSource().equals(right)) n = 3;
            else n = 4;
            switch (n){
                case 0:
                    Board.novo_jogo();
                    Board.print();
                    break;
                case 1:
                    Board.esquerda();
                    Board.print();
                    break;
                case 2:
                    Board.baixo();
                    Board.print();
                    break;
                case 3:
                    Board.direita();
                    Board.print();
                    break;
                case 4:
                    janela_menu();
                    break;
                }
        }
    };
    init.addActionListener(accao_botoes);
    left.addActionListener(accao_botoes);
    down.addActionListener(accao_botoes);
    right.addActionListener(accao_botoes);
    menu.addActionListener(accao_botoes);
    while(true){
        frame.repaint();
        try{
            Thread.sleep(10);
        }catch(Exception e){}
    }
}

it doesnt update the panel, infact it doesnt update anything :( i tryed grelha.validate(), grelha.repaint() and nothing seems to work, am i missing anything?

Anyone can help me?

Answer 1

1. create Board instance and keep reference to this object Board board=Board.painel();

2. operate on that instance board.direita(); board.print(); board.direita(); board.print();

3. inplementataion of direita in class Board should change JLabel properties

4. remove while(true) loop. EDT will update swing widgets.

Example of direita (other movings make in similar way)

public void direita() {
    if (currentX+1 < colunas) ++currentX;
    JLabel label = labels[currentY][currentX];
    label.setBackground(Color.YELLOW);
}

Example of painel

public static Board painel(){
    // Painel Grelha
    return new Board();
}

and Board constructor

public Board() {
    GridLayout grid_grelha = new GridLayout(linhas, colunas, 3, 3);
    setLayout(grid_grelha);
    setOpaque(true);
    setSize(janela_x - 140, janela_y-140);
    setLocation(70, 20);
    setBackground(Color.GREEN);
    // criar JLabels
    for (int num = 0; num < linhas; num++){
        for (int num2 = 0; num2 < colunas; num2++){
            JLabel label = new JLabel();
            //label.setText(String.format("%d,%d",num,num2));
            label.setOpaque(true);
            label.setBackground(select_cor(num,num2));
            label.setHorizontalAlignment(SwingConstants.CENTER);
            add(label);
            labels[num][num2]=label;
        }
    }
}