I'm learning JAVA GUI

How Can I add a value from my JButton(1,2,3,[...]) to a specific JTextField with click?

Example:

First> Click to JTextField1

2nd> click on JButton 3

How can I add value JButton 3 to my JTextField selected?

I know how to put a JButton value in a single JTextField, but I don't know how to do it in several different JTextField

I saw some related posts, but I can't implement them in my code, maybe because I don't understand English very well and I can end up confusing some things

I'm trying this:

 package jamilzin.magicsquare;
    import javax.swing.*;
     import java.awt.*;
     import java.awt.event.*;



public class MagicSquare implements ActionListener {

    //declarando
    JFrame frame;
    JPanel panel,panelFunctions;
    JButton[] numbers = new JButton[10];
    JTextField[] positions = new JTextField[9];
    JButton[] functions = new JButton[2];
    
    
    void magicSquare(){
    
    frame = new JFrame("Quadrado Magico");
    frame.setSize(500,500);
    panel = new JPanel();
    panelFunctions = new JPanel();
    
     numbers[1] = new JButton("1");
     numbers[2] = new JButton("2");
     numbers[3] = new JButton("3");
     numbers[4] = new JButton("4");
     numbers[5] = new JButton("5");
     numbers[6] = new JButton("6");
     numbers[7] = new JButton("7");
     numbers[8] = new JButton("8");
     numbers[9] = new JButton("9");
     
     functions[0]= new JButton("Limpar");
     functions[1]= new JButton("Sair");
     
     
    for(int i=1;i<10;i  ){
     numbers[i].addActionListener(this);
     numbers[i].setBackground(Color.lightGray);
    }
    
    for(int i=0; i<9;i  ){
    positions[i] = new JTextField();
positions[i].addActionListener(this);
}
 


    panel.setBounds(0, 0, 500, 400);
   panel.setLayout(new GridLayout(6,3,0,0));
    panelFunctions.setBounds(50,410,400,30);
   panelFunctions.setLayout(new GridLayout(1,2,250,0));
   
    panel.add(positions[0]);
    panel.add(positions[1]);
    panel.add(positions[2]);
    panel.add(positions[3]);
    panel.add(positions[4]);
    panel.add(positions[5]);
    panel.add(positions[6]);
    panel.add(positions[7]);
    panel.add(positions[8]);
    panel.add(numbers[1]);
    panel.add(numbers[2]);
    panel.add(numbers[3]);
    panel.add(numbers[4]);
    panel.add(numbers[5]);
    panel.add(numbers[6]);
    panel.add(numbers[7]);
    panel.add(numbers[8]);
    panel.add(numbers[9]);
    panelFunctions.add(functions[0]);
    panelFunctions.add(functions[1]);
    frame.setLayout(null);

  
    frame.setVisible(true);
      frame.add(panel);
    frame.add(panelFunctions);
    }
    
    
    @Override
    public void actionPerformed(ActionEvent e) {

   if(e.getSource()==positions[1]){
       positions[1].setText("5");
   //    positions[1].setText(e.getActionCommand());

   }
 
    }

       public static void main(String[] args) {
        MagicSquare quadrado = new MagicSquare();
        quadrado.magicSquare();
    }


    
    
}

its my GUI

CodePudding user response：

You'll want to have a look at How to Write a Focus Listener

Basically, you need to attach a FocusListener to each text field. When a text field gains focus, you will want to set a property to the instance of the JTextField which gained focus. When you tap a button, you use this property to set the text (assumming it's not null)

import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class Main {
    public static void main(String[] args) {
        new Main();
    }

    public Main() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {
        private JTextField[] positions = new JTextField[9];
        private JButton[] numbers = new JButton[10];

        private JTextField lastFocusedField;

        public TestPane() {
            JPanel textFieldPane = new JPanel(new GridLayout(3, 3));
            for (int index = 0; index < positions.length; index  ) {
                positions[index] = new JTextField(10);
                positions[index].addFocusListener(new FocusAdapter() {
                    @Override
                    public void focusGained(FocusEvent e) {
                        lastFocusedField = (JTextField)e.getSource();
                    }
                });
                textFieldPane.add(positions[index]);
            }

            JPanel buttonGridPane = new JPanel(new GridLayout(3, 3));
            for (int index = 0; index < numbers.length; index  ) {
                numbers[index] = new JButton(Integer.toString(index));
                numbers[index].addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        if (lastFocusedField != null) {
                            lastFocusedField.setText(e.getActionCommand());
                        }
                    }
                });
            }
            for (int index = 0; index < 9; index  ) {
                buttonGridPane.add(numbers[index]);
            }
            JPanel numbersPane = new JPanel(new GridLayout(2, 1));
            numbersPane.add(buttonGridPane);
            numbersPane.add(numbers[9]);

            GridBagConstraints gbc = new GridBagConstraints();
            setLayout(new GridBagLayout());
            gbc.gridwidth = GridBagConstraints.REMAINDER;

            add(textFieldPane, gbc);
            add(numbersPane, gbc);
        }
    }
}

Now, you need to make some decisions, when you tap a button should you reset the "last focused text field" or not. Because otherwise, you can keep tapping buttons and the last focused text field will keep updating.

CodePudding user response：

    @Override
    public void actionPerformed(ActionEvent e) {
      JButton btnPressed = (JButton)e.getSource();
      for(int i=0; i<numbers.length;i  ){
        if(numbers[i] == btnPressed){
            positions[i-1].setText(btnPressed.getText());
        }
     }

    }