CODEWITHSUNDEEP
javaswingjpanellayout-managergridbaglayout
acn3
acn3

Reputation: 358

Improper sizing using GridBagLayout

I am trying to use a GridBagLayout to have a JFrame that contains a JPanel that has a grid layout and a JPanel with just a large button. I want the rows to all be the same size, and the JPanel with the JButton to be the same size as one row. However, the button panel, which is currently empty, is about 1/3 of the JFrame. I'm not quite sure what's happening, but it is pretty important to me that I maintain this structure because the rest of my code uses this. Any help is appreciated, and thank you in advance.

This is my code:

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

public class Minesweeper extends JPanel {
        private final int SIZE = 7;

        public void startGame(){
                JFrame holder = new JFrame();
                JPanel window = new JPanel();
                JPanel pan = new JPanel();
                holder.setLayout(new GridBagLayout());
                GridBagConstraints con = new GridBagConstraints();
                con.weightx = 1;
                con.weighty = 1;
                con.gridx = 0;
                con.gridy = 0;
                con.fill = GridBagConstraints.BOTH;
                con.gridheight = SIZE;
                con.gridwidth = SIZE;
                holder.getContentPane().setBackground(Color.darkGray);
                holder.setSize(450, 450);
                holder.setResizable(false);
                holder.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                window.setBackground(Color.darkGray);
                window.setLayout(new GridLayout(SIZE, SIZE));
                for (int c=0; c<(SIZE*SIZE); c++){
                        int row = (c/SIZE);
                        int col = (c%SIZE);
                        JPanel p = new JPanel();
                        p.setBackground(Color.gray);
                        Border b = BorderFactory.createEtchedBorder(EtchedBorder.RAISED);
                        p.setBorder(b);
                        window.add(p);
                }
                holder.add(window, con);
                con.gridx = 0;
                con.gridy = SIZE+1;
                con.gridheight = 0;
                con.gridwidth = SIZE;
                holder.add(pan, con);
                holder.setVisible(true);
        }

        public static void main(String[] args){
                Minesweeper start = new Minesweeper();
                start.startGame();
        }
}

This is what is being shown:

https://i.sstatic.net/HvguY.png

Upvotes: 0

Views: 47

Answers (1)

camickr
camickr

Reputation: 324098

con.gridy = SIZE+1;

You can't specify a gridy value of 8. There are only two components added to the grid. The grid doesn't know that one of your panels happens to contain 7 rows of components. So the value should be 1.

This won't solve the problem but should clear up a misunderstanding of how GridBagLayout works.

holder.setSize(450, 450);

You are manually setting a size to the frame. Each component is originally sized at its preferred size. When there is extra space in the frame the space is distributed equally between the two components.

You should NOT be setting the size. Each component should determine its own size and then you should use pack(). So you need to use custom components that override the getPreferredSize() method to return the appropriate size for each component so pack() can do its job.

Also, the pack() is done just before the setVisible().

Upvotes: 1

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