How do I scroll or wrap JTabbedPane tab layout?

JTabbedPane component tab layout policy of can be either set to JTabbedPane.SCROLL_TAB_LAYOUT or JTabbedPane.WRAP_TAB_LAYOUT. This layout policy will control the display of the tabs when the tabs cannot be displayed in one go. By the default the layout policy is set to JTabbedPane.WRAP_TAB_LAYOUT. Changing tab layout policy to JTabbedPane.SCROLL_TAB_LAYOUT makes the tabs scrollable. A button for scrolling left-right or up-down will be displayed in the tabbed pane.

package org.kodejava.example.swing;

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

public class TabbedPaneTabLayoutPolicy extends JPanel {
    public TabbedPaneTabLayoutPolicy() {
        initializeUI();
    }

    public static void showFrame() {
        JPanel panel = new TabbedPaneTabLayoutPolicy();
        panel.setOpaque(true);

        JFrame frame = new JFrame("TabbedPane Tab Layout Policy Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setContentPane(panel);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                TabbedPaneTabLayoutPolicy.showFrame();
            }
        });
    }

    private void initializeUI() {
        this.setLayout(new BorderLayout());
        this.setPreferredSize(new Dimension(400, 200));

        // Creates a JTabbedPane with scroll tab layout policy
        JTabbedPane pane = new JTabbedPane(JTabbedPane.TOP,
            JTabbedPane.SCROLL_TAB_LAYOUT);
        pane.addTab("One", createPanel("One"));
        pane.addTab("Two", createPanel("Two"));
        pane.addTab("Three", createPanel("Three"));
        pane.addTab("Four", createPanel("Four"));
        pane.addTab("Five", createPanel("Five"));
        pane.addTab("Six", createPanel("Six"));
        pane.addTab("Seven", createPanel("Seven"));
        pane.addTab("Eight", createPanel("Eight"));
        pane.addTab("Nine", createPanel("Nine"));
        pane.addTab("Ten", createPanel("Ten"));

        this.add(pane, BorderLayout.CENTER);
    }

    private JPanel createPanel(String title) {
        JPanel panel = new JPanel();
        panel.setLayout(new BorderLayout());
        panel.add(new JLabel(title), BorderLayout.NORTH);
        return panel;
    }
}

Here is the screenshot of the code snippet created above. You can see that a button at the top right of the tabbed pane is added so that you can scroll to navigate the hidden tabs.

JTabbedPane Tab Layout Policy Demo

How do I place swing component using absolute coordinates?

In this example you can see how we do an absolute positioning to a swing component in the content panel. In this example we use a JPanel as the container and we didn’t set a layout manager into it.

To position the component on the container we use the setBounds() method of the component. This method takes the x and y coordinate position and also the width and height of the component.

package org.kodejava.example.swing;

import javax.swing.*;

public class AbsolutePositionDemo extends JFrame {
    public AbsolutePositionDemo() {
        initializeUI();
    }

    private void initializeUI() {
        setSize(400, 400);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        JPanel panel = new JPanel(null);

        JTextField textField = new JTextField(20);
        textField.setBounds(50, 50, 100, 20);

        JButton button = new JButton("Button");
        button.setBounds(200, 100, 100, 20);

        JCheckBox checkBox = new JCheckBox("Check Me!");
        checkBox.setBounds(300, 250, 100, 20);

        panel.add(textField);
        panel.add(button);
        panel.add(checkBox);

        setContentPane(panel);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new AbsolutePositionDemo().setVisible(true);
            }
        });
    }
}

How do I arrange the swing component using GridLayout?

This example use the GridLayout to create a four by four grid layout. One each of the grid we place a JTextField component to read user inputs.

package org.kodejava.example.swing;

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

public class GridLayoutDemo extends JFrame {
    public GridLayoutDemo() {
        initializeUI();
    }

    private void initializeUI() {
        setSize(300,300);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        // Create a four by four GridLayout with 5 pixel horizontal and vertical
        // gap between each row or column.
        GridLayout grid = new GridLayout(4, 4, 5, 5);
        //grid.setColumns(4);
        //grid.setRows(4);
        //grid.setHgap(5);
        //grid.setVgap(5);

        setLayout(grid);

        JTextField[][] textFields = new JTextField[4][4];
        for (int i = 0; i < textFields.length; i++) {
            for (int j = 0; j < textFields[i].length; j++) {
                textFields[i][j] = new JTextField(String.valueOf((i + 1) * (j + 1)));
                // Put the text at the center of the JTextField component
                textFields[i][j].setHorizontalAlignment(SwingConstants.CENTER);

                getContentPane().add(textFields[i][j]);
            }
        }
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new GridLayoutDemo().setVisible(true);
            }
        });
    }
}

How do I arrange the swing component using FlowLayout?

In this example you can see how to arrange the swing components using the FlowLayout manager. This manager arrange the component in a directional flow based on the container component orientation such as ComponentOrientation.LEFT_TO_RIGHT and ComponentOrientation.RIGHT_TO_LEFT.

package org.kodejava.example.swing;

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

public class FlowLayoutExample extends JFrame {
    public FlowLayoutExample() {
        initialize();
    }

    private void initialize() {
        setSize(250, 150);
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        // Create a new FlowLayout manager and set the component arrangement to
        // left justified. The other arrangement if FlowLayout.CENTER,
        // FlowLayout.RIGHT, FlowLayout.LEADING and FlowLayout.TRAILING.
        FlowLayout layoutManager = new FlowLayout(FlowLayout.RIGHT);

        // Set the horizontal and vertical gap between component laid in the
        // content pane to 10 pixels.
        layoutManager.setHgap(10);
        layoutManager.setVgap(10);
        setLayout(layoutManager);

        // Set the container's component orientation from the right to left. 
        // This make the first component placed on the right top part of the
        // container.
        getContentPane().setComponentOrientation(ComponentOrientation.RIGHT_TO_LEFT);

        // Adds some textfields the the frame panel.
        JTextField[][] textFields = new JTextField[3][3];
        for (int i = 0; i < textFields.length; i++) {
            for (int j = 0; j < textFields[i].length; j++) {
                textFields[i][j] = new JTextField(5);
                textFields[i][j].setText(String.valueOf(((i + 1) * (j + 1))));

                getContentPane().add(textFields[i][j]);
            }
        }        
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new FlowLayoutExample().setVisible(true);
            }
        });
    }
}