JSpinners and JButton in GridBagLayout Swing

Question

This is my code creating my message panel :

private class MessagePane extends JPanel {
    private MessagePane() {
        setLayout(new GridBagLayout());
        setBackground(backgroundColor);
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.insets = new Insets(4, 4, 4, 4);

        add(allowButton, gbc);
        gbc.gridx = 1;
        add(blockButton, gbc);

        gbc.gridwidth = 2;
        gbc.gridx = 0;
        gbc.gridy = 1;
        gbc.weightx = 1;
        gbc.weighty = 1;
        add(timerL, gbc);
        gbc.fill = GridBagConstraints.BOTH;
        add(new JScrollPane(messageArea), gbc);

        gbc = new GridBagConstraints();
        gbc.gridy = 2;
        gbc.gridx = 0;
        add(countryList, gbc);

        gbc.gridx = 1;
        add(msgList, gbc);

        gbc.gridx = 2;
        add(sendButton, gbc);

        setVisible(true);
    }
}

And view of this looks like :

The view that I want to achieve :

Can you help me with this?

Answer 1

I created the following GUI using GridBagLayout.

I had to put the top two buttons in their own JPanel so that they would be the same size. I used a GridBagLayout for both the button panel and the main panel.

I created a GridBagConstraints for each and every Swing component. That way, I can set the insets how I wish and can specify a different anchor and fill for each component.

I had to guess which Swing components the OP used since they weren't defined in the code he posted.

Here's the complete, runnable example that generated the GUI.

import java.awt.Component;
import java.awt.Container;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSpinner;
import javax.swing.JTextArea;
import javax.swing.SpinnerListModel;
import javax.swing.SwingUtilities;

public class MessageApplication implements Runnable {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new MessageApplication());
    }

    @Override
    public void run() {
        JFrame frame = new JFrame("Message Panel");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.add(new MessagePanel().getPanel());
        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    public class MessagePanel {

        private JPanel panel;

        public MessagePanel() {
            // top, left, bottom, right
            Insets topLeftInsets = new Insets(10, 10, 10, 10);
            Insets topInsets = new Insets(10, 0, 10, 10);
            Insets leftInsets = new Insets(0, 10, 10, 10);
            Insets insets = new Insets(0, 0, 10, 10);
            Insets messageInsets = new Insets(2, 4, 2, 4);
            Insets zeroInsets = new Insets(0, 0, 0, 0);

            panel = new JPanel();
            panel.setLayout(new GridBagLayout());

            int gridy = 0;

            JPanel buttonPanel = new JPanel();
            buttonPanel.setLayout(new GridBagLayout());

            JButton allowButton = new JButton("ALLOW");
            addComponent(buttonPanel, allowButton, 0, gridy, 1, 1, 
                    topLeftInsets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);

            JButton blockButton = new JButton("BLOCK");
            addComponent(buttonPanel, blockButton, 1, gridy, 1, 1, 
                    topInsets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);

            addComponent(panel, buttonPanel, 0, gridy++, 6, 1, 
                    zeroInsets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);

            JTextArea messageArea = new JTextArea(12, 30);
            messageArea.setEditable(false);
            messageArea.setMargin(messageInsets);
            messageArea.setText("I'm a message area.");
            JScrollPane scrollPane = 
                    new JScrollPane(messageArea);
            addComponent(panel, scrollPane, 0, gridy++, 6, 1, 
                    leftInsets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);

            String[] countryStrings = { "US", "CA" };
            SpinnerListModel countryModel = 
                    new SpinnerListModel(countryStrings);
            JSpinner countryList = new JSpinner(countryModel);
            addComponent(panel, countryList, 0, gridy, 1, 1, 
                    leftInsets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);

            String[] msgStrings = { "Message to the client", 
                    "Message to the shipper" };
            SpinnerListModel msgModel = 
                    new SpinnerListModel(msgStrings);
            JSpinner msgList = new JSpinner(msgModel);
            addComponent(panel, msgList, 1, gridy, 4, 1, 
                    insets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);

            JButton sendButton = new JButton("SEND");
            addComponent(panel, sendButton, 5, gridy++, 1, 1, 
                    insets, GridBagConstraints.CENTER,
                    GridBagConstraints.HORIZONTAL);
        }

        private void addComponent(Container container, 
                Component component, int gridx, int gridy, 
                int gridwidth, int gridheight, Insets insets, 
                int anchor, int fill) {
            GridBagConstraints gbc = new GridBagConstraints(
                    gridx, gridy, gridwidth, gridheight, 
                    1.0, 1.0, anchor, fill, insets, 0, 0);
            container.add(component, gbc);
        }


        public JPanel getPanel() {
            return panel;
        }

    }

}