Multiple JPanels with different widths inside a JFrame using GridBagLayout
I am trying to create two panels with different widths in a JFrame. I want my right pane to have the width of the left pane. I am trying to use a GridBagLayout using gridwidth = 1 for my left pane and gridwidth = 2 for my right pane. But instead of getting different widths, I get two panels with the same width. What should I change? Any help would be appreciated.
import javax.swing.*;
import java.awt.*;
public class AppFrame2 extends JFrame {
GridBagLayout gbl;
GridBagConstraints gbc;
JPanel leftpanel;
JPanel rightpanel;
public AppFrame2() {
this.setSize(500, 500);
this.setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.getContentPane().setBackground(Color.BLACK);
// Settning Frame Layout
gbl = new GridBagLayout();
gbc = new GridBagConstraints();
this.setLayout(gbl);
gbc.fill = GridBagConstraints.BOTH;
gbc.weightx = 1.0;
gbc.weighty = 1.0;
// Add Panels
leftpanel = new JPanel();
leftpanel.setBackground(Color.green);
this.addPanels(0, 0, 1, 1, leftpanel); // row, col, height, width component
rightpanel = new JPanel();
rightpanel.setBackground(Color.red);
this.addPanels(0, 1, 1, 2, rightpanel);
}
private void addPanels(int row, int col, int height, int width,
Component com) {
gbc.gridx = col;
gbc.gridy = row;
gbc.gridheight = height;
gbc.gridwidth = width;
gbl.setConstraints(com, gbc);
this.getContentPane().add(com);
}
public static void main(String[] args) {
new AppFrame2();
}
}
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1 answer
Your problem is that you are not specifying the width of the columns. Adding a row gbl.columnWidths = new int[] {500/3, 500/3*2};
will set the column widths to whatever you want. I've added lines to your code here to make it work :)
import javax.swing.*;
import java.awt.*;
public class AppFrame2 extends JFrame {
GridBagLayout gbl;
GridBagConstraints gbc;
JPanel leftpanel;
JPanel rightpanel;
public AppFrame2() {
this.setSize(500, 500);
this.setResizable(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
this.getContentPane().setBackground(Color.BLACK);
// Settning Frame Layout
gbl = new GridBagLayout();
//************* New code **************//
gbl.columnWidths = new int[] {500/3, 500/3*2};
gbl.rowHeights = new int[] {500};
gbl.columnWeights = new double[] {1, 1};
gbl.rowWeights = new double[] {1};
//************* End code **************//
gbc = new GridBagConstraints();
this.setLayout(gbl);
gbc.fill = GridBagConstraints.BOTH;
gbc.weightx = 1.0;
gbc.weighty = 1.0;
// Add Panels
leftpanel = new JPanel();
leftpanel.setBackground(Color.green);
this.addPanels(0, 0, 1, 1, leftpanel); // row, col, height, width component
rightpanel = new JPanel();
rightpanel.setBackground(Color.red);
this.addPanels(0, 1, 1, 2, rightpanel);
}
private void addPanels(int row, int col, int height, int width,
Component com) {
gbc.gridx = col;
gbc.gridy = row;
gbc.gridheight = height;
gbc.gridwidth = width;
gbl.setConstraints(com, gbc);
this.getContentPane().add(com);
}
public static void main(String[] args) {
new AppFrame2();
}
}
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