Vertical BoxLayout-managed container : BoxLayout « Swing « Java Tutorial

import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.LayoutManager;

import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class VerticalBoxLayoutManagerContainerTest {

  public static void main(String[] args) {
    JFrame f = new JFrame();
    Container pane = new BoxPanel();
    BoxLayout bl = new BoxLayout(pane, BoxLayout.Y_AXIS);
    for (float align = 0.0f; align <= 1.0f; align += 0.25f) {
      JButton button = new JButton("X Alignment = " + align);
      pane.add(Box.createRigidArea(new Dimension(0, 15)));
    f.setSize(400, 300);

class BoxPanel extends JPanel {

  public void paintChildren(Graphics g) {
    Dimension size = getSize();
    LayoutManager manager = getLayout();
    if ((manager != null) && (manager instanceof BoxLayout)) {
      BoxLayout layout = (BoxLayout) manager;
      boolean vertical = true;
      if (vertical) {
        int axis = (int) (layout.getLayoutAlignmentX(this) * size.width);
        g.fillRect(axis - 1, 0, 3, size.height);
      } else {
        int axis = (int) (layout.getLayoutAlignmentY(this) * size.height);
        g.fillRect(0, axis - 1, size.width, 3);


14.87.1.Using a BoxLayout ManagerUsing a BoxLayout Manager
14.87.2.Creating a BoxLayoutCreating a BoxLayout
14.87.3.A Simple BoxLayout TestA Simple BoxLayout Test
14.87.4.Struts and GlueStruts and Glue
14.87.5.Y-Axis AlignmentY-Axis Alignment
14.87.6.X-Axis AlignmentX-Axis Alignment
14.87.7.Drawing Borders Within a BoxLayout-Managed ContainerDrawing Borders Within a BoxLayout-Managed Container
14.87.8.Separating Components in a Row or Column
14.87.9.Glue spreads the components as far apart as possible.
14.87.10.Strut spreads the components apart by a fixed distance
14.87.11.Laying Out Components in a Row or Column
14.87.12.A vertical box container arranges the components top-to-bottom aligned in their preferred sizes.
14.87.13.Vertical BoxLayout-managed container
14.87.14.Align your components in horizontal or vertical layout
14.87.15.BoxLayout: set a rigid area among our components.