what do I need to change in my code so when I maximize the window, then the buttons will expand proportionally?
When I run the program, it's starts with my chosen size but I want to use the maximize... Thanks.
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Insets;
import javax.swing.JTextField;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.BorderFactory;
import javax.swing.WindowConstants;
public class Calculator extends JFrame
{
protected JTextField display;
protected JButton b1 = new JButton("1");
protected JButton b2 = new JButton("2");
protected JButton b3 = new JButton("3");
protected JButton b4 = new JButton("4");
protected JButton b5 = new JButton("5");
protected JButton b6 = new JButton("6");
protected JButton b7 = new JButton("7");
protected JButton b8 = new JButton("8");
protected JButton b9 = new JButton("9");
protected JButton b0 = new JButton("0");
protected JButton addition = new JButton("+");
protected JButton subtraction = new JButton("-");
protected JButton multiplication = new JButton("*");
protected JButton division = new JButton("/");
protected JButton result = new JButton("=");
protected JButton allClear = new JButton("C");
protected JButton decimalPoint = new JButton(".");
public Calculator()
{
super("Calculator");
Handler handler = new Handler();
allClear.addActionListener(handler);
addition.addActionListener(handler);
subtraction.addActionListener(handler);
multiplication.addActionListener(handler);
division.addActionListener(handler);
result.addActionListener(handler);
decimalPoint.addActionListener(handler);
b0.addActionListener(handler);
b1.addActionListener(handler);
b2.addActionListener(handler);
b3.addActionListener(handler);
b4.addActionListener(handler);
b5.addActionListener(handler);
b6.addActionListener(handler);
b7.addActionListener(handler);
b8.addActionListener(handler);
b9.addActionListener(handler);
addition.setToolTipText("Addition");
subtraction.setToolTipText("Subtraction");
multiplication.setToolTipText("Multiplication");
division.setToolTipText("Division");
result.setToolTipText("Result");
allClear.setToolTipText("All Clear");
decimalPoint.setToolTipText("Decimal point");
display = new JTextField(10);
display.setBorder(BorderFactory.createLineBorder(Color.CYAN));
// Set a panel's layout manager using the JPanel constructor
JPanel mainPanel = new JPanel(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.gridy = 0;
c.gridwidth = 3;
c.fill = GridBagConstraints.HORIZONTAL;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(display, c);
c = new GridBagConstraints();
c.gridy = 0;
c.gridwidth = 1;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(allClear, c);
c = new GridBagConstraints();
c.gridy = 1;
c.gridwidth = 1;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b1, c);
c = new GridBagConstraints();
c.gridy = 1;
c.gridwidth = 1;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b2, c);
c = new GridBagConstraints();
c.gridy = 1;
c.gridwidth = 1;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b3, c);
c = new GridBagConstraints();
c.gridy = 1;
c.gridwidth = 1;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(division, c);
c = new GridBagConstraints();
c.gridy = 2;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b4, c);
c = new GridBagConstraints();
c.gridy = 2;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b5, c);
c = new GridBagConstraints();
c.gridy = 2;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b6, c);
c = new GridBagConstraints();
c.gridy = 2;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(multiplication, c);
c = new GridBagConstraints();
c.gridy = 3;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b7, c);
c = new GridBagConstraints();
c.gridy = 3;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b8, c);
c = new GridBagConstraints();
c.gridy = 3;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b9, c);
c = new GridBagConstraints();
c.gridy = 3;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(subtraction, c);
c = new GridBagConstraints();
c.gridy = 4;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(b0, c);
c = new GridBagConstraints();
c.gridy = 4;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(decimalPoint, c);
c = new GridBagConstraints();
c.gridy = 4;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(result, c);
c = new GridBagConstraints();
c.gridy = 4;
c.insets = new Insets(5, 5, 5, 5);
mainPanel.add(addition, c);
add(mainPanel);
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
pack();
}
You need to set weightx and weighty of the constraints. The relation between these values control how 'unused' space is distributed along the cells. See the GridBagConstraints documentation.
You could set the weightx and weighty constraint to 1.0 or any other strictly positive value.
The fill field must be set to BOTH so each button occupy its whole cell.
Mini example, reduced for readability:
public class MiniCalculator extends JFrame {
public static void main(String[] args) {
new MiniCalculator().setVisible(true);
}
private JTextField display = new JTextField(10);
private JButton clear = new JButton("C");
private JButton b1 = new JButton("1");
private JButton b2 = new JButton("2");
private JButton b3 = new JButton("3");
public MiniCalculator() {
setDefaultCloseOperation(DISPOSE_ON_CLOSE);
setLayout(new GridBagLayout());
GridBagConstraints constraint = new GridBagConstraints();
constraint.insets = new Insets(5, 5, 5, 5);
constraint.weighty = 1.0;
constraint.weightx = 1.0;
constraint.gridy = 0;
constraint.gridwidth = 2;
constraint.fill = GridBagConstraints.HORIZONTAL;
add(display, constraint);
constraint.gridwidth = 1;
constraint.fill = GridBagConstraints.BOTH;
add(clear, constraint);
constraint.gridy = 1;
add(b1, constraint);
add(b2, constraint);
add(b3, constraint);
pack();
setLocationRelativeTo(null);
}
}
Note: there is no need to create all that constraints, just create one and change it between adding the components. The constraint is cloned when a component is added.