更改JButton大小的问题

Question

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I'm trying to make a mine sweeper game with Swing library (just for training). I spotted a problem when I tried to change size of a button with setSize() method (part of Container class). One of my previous program was able to handle that (with ActionListener)

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class ButtonChanger extends JFrame {

JButton big, small, dis;
JLabel message, poof;

public ButtonChanger(){
    setLayout(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();

    message = new JLabel("Click to make it");
    c.fill = GridBagConstraints.HORIZONTAL;
    c.gridx = 0;
    c.gridy = 0;
    add(message, c);


    big =  new JButton("BIG");
    big.setSize(30, 30); // no reaction for this call 
    c.fill = GridBagConstraints.HORIZONTAL;
    c.gridx = 0;
    c.gridy = 1;
    c.gridwidth = 1;
    add(big, c);


    small = new JButton("small");
    c.fill = GridBagConstraints.HORIZONTAL;
    c.gridx = 1;
    c.gridy = 1;
    add(small, c);


    dis = new JButton("disapear");
    c.fill = GridBagConstraints.HORIZONTAL;
    c.gridx = 3;
    c.gridy = 1;
    add(dis, c);

    poof = new JLabel("  poof!");
    c.fill = GridBagConstraints.HORIZONTAL;
    c.gridx = 3;
    c.gridy = 1;
    poof.setVisible(false);
    add(poof, c);

    big.setSize(300,300); // same story

    event a = new event();
    big.addActionListener(a);
    small.addActionListener(a);
    dis.addActionListener(a);
}

public class event implements ActionListener{
    public void actionPerformed(ActionEvent a){

        String op = a.getActionCommand();

        if(op.equals("BIG")){
            big.setSize(50,50); // finaly!
        } else if(op.equals("small")){
            small.setSize(10,10);
        } else if(op.equals("disapear")){
            dis.setVisible(false);
            poof.setVisible(true);
        } 

    }
}

public static void main(String args[]){
    ButtonChanger gui = new ButtonChanger();
    gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    gui.setVisible(true);
    gui.setSize(250,250);
    gui.setTitle("");
}
}

But when I tried to use same solution here - nothing happened.

import java.util.Random;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class Board extends JPanel
               implements ActionListener{
private Integer pixelWidth;
private Integer pixelHeight;
public Field[][] board;


private Random generator = new Random();

public Board(int width,int height){ // width - x axis scaled with "button" unit
    // height -  y axis scaled with "button" unit

    setLayout(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();

    board = new Field[width][height];

    pixelWidth = width * Field.fieldW;
    pixelHeight = height * Field.fieldH;

    for(int i = 0;i < height;i++)
        for(int j = 0;j < width;j++){
            board[i][j] = new Field(generator.nextBoolean());
        }

    for(int i = 0;i < height;i++){
        c.fill = GridBagConstraints.HORIZONTAL;
        c.gridy = i;
        for(int j = 0;j < width;j++){
            c.gridx = j;
            add(board[i][j].getFieldButton(),c);
            add(board[i][j].getFieldLabel(),c);
        }
    }

/*  for(int i = 0;i < height;i++)
        for(int j = 0;j < width;j++){
            board[i][j].setField();
        }*/

}
public void actionPerformed(ActionEvent e){
    String co = e.getActionCommand();
    if(co.equals(" ")){ // button is single space sign  
        for(int i = 0;i < 10;i++)
            for(int j = 0;j < 10;j++){
                board[i][j].setField(); //inside this method is call for setSize() for fieldButton
                }
    }
}
}

Previously I changed Board class to make it inhetitate after JFrame (set up as main GUI frame in whole code) but that gave me same output as original.

Did I mess up something?

Answer 1

big =  new JButton("BIG");
big.setSize(30, 30); // no reaction for this call 
c.fill = GridBagConstraints.HORIZONTAL;

There is no reaction for big.setSize... because then in GridBagConstraints you set fill to horizontal, so button will be "stretched" to fill horizontally.

Instead use c.fill = GridBagConstraints.NONE

fill

Used when the component's display area is larger than the component's requested size to determine whether and how to resize the component. Valid values (defined as GridBagConstraints constants) include NONE (the default), HORIZONTAL (make the component wide enough to fill its display area horizontally, but do not change its height), VERTICAL (make the component tall enough to fill its display area vertically, but do not change its width), and BOTH (make the component fill its display area entirely).

You can read more here: https://docs.oracle.com/javase/tutorial/uiswing/layout/gridbag.html