Question

I have this gui; and when the height is not big enough the panes will overlap each other. I have to set it at least 200, so I can completely see the two rows; but when it is set at 200, then I have like a big empty row at the end, and I don’t want that. How could I fix this? Thanks.

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

public class MyFrame extends JFrame {

    JButton panicButton;
    JButton dontPanic;
    JButton blameButton;
    JButton newsButton;
    JButton mediaButton;
    JButton saveButton;
    JButton dontSave;

    public MyFrame() {
        super("Crazy App");
        setSize(400, 150);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel row1 = new JPanel();
        panicButton = new JButton("Panic");
        dontPanic = new JButton("No Panic");
        blameButton = new JButton("Blame");
        newsButton = new JButton("News");
        //adding first row
        GridLayout grid1 = new GridLayout(4, 2, 10, 10);
        setLayout(grid1);
        FlowLayout flow1 = new FlowLayout(FlowLayout.CENTER, 10, 10);
        row1.setLayout(flow1);
        row1.add(panicButton);
        row1.add(dontPanic);
        row1.add(blameButton);
        row1.add(newsButton);
        add(row1);
        //adding second row
        JPanel row2 = new JPanel();
        mediaButton = new JButton("Blame");
        saveButton = new JButton("Save");
        dontSave = new JButton("No Save");
        GridLayout grid2 = new GridLayout(3, 2, 10, 10);
        setLayout(grid2);
        FlowLayout flow2 = new FlowLayout(FlowLayout.CENTER, 10, 10);
        row2.setLayout(flow2);        
        row2.add(mediaButton);
        row2.add(saveButton);
        row2.add(dontSave);
        add(row2);       

        setVisible(true);       

    }

    public static void main(String[] args) {
        MyFrame frame = new MyFrame();
    }   
}

Answer 1

1. The original code set the layout for one panel on two separate occasions. For clarity, set it once in the constructor.
2. The 2nd layout specified 3 rows
3. Call pack() on the top-level container to have the GUI reduce to the minum sze needed for the components.

End result

---

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

public class MyFrame17 extends JFrame {

    JButton panicButton;
    JButton dontPanic;
    JButton blameButton;
    JButton newsButton;
    JButton mediaButton;
    JButton saveButton;
    JButton dontSave;

    public MyFrame17() {
        super("Crazy App");
        setLayout(new GridLayout(2, 2, 10, 10));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel row1 = new JPanel();
        panicButton = new JButton("Panic");
        dontPanic = new JButton("No Panic");
        blameButton = new JButton("Blame");
        newsButton = new JButton("News");
        FlowLayout flow1 = new FlowLayout(FlowLayout.CENTER, 10, 10);
        row1.setLayout(flow1);
        row1.add(panicButton);
        row1.add(dontPanic);
        row1.add(blameButton);
        row1.add(newsButton);
        add(row1);
        //adding second row
        JPanel row2 = new JPanel();
        mediaButton = new JButton("Blame");
        saveButton = new JButton("Save");
        dontSave = new JButton("No Save");
        FlowLayout flow2 = new FlowLayout(FlowLayout.CENTER, 10, 10);
        row2.setLayout(flow2);        
        row2.add(mediaButton);
        row2.add(saveButton);
        row2.add(dontSave);
        add(row2);       

        pack();
        setVisible(true);       
    }

    public static void main(String[] args) {
        MyFrame17 frame = new MyFrame17();
    }   
}

Further tips

1. Don’t extend frame, just use an instance of one.
2. Build the entire GUI in a panel which can then be added to a frame, applet, dialog..
3. When developing test classes, give them a more sensible name than MyFrame. A good word to add is Test, then think about what is being tested. This is about the layout of buttons, so ButtonLayoutTest might be a good name.
4. GUIs should be started on the EDT.