OverlayLayout: center : OverlayLayout « Swing « Java Tutorial

1. Java Tutorial
2. Swing
3. OverlayLayout

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.LayoutManager;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.OverlayLayout;

public class OverlaySampleCentral {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Overlay Example");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel panel = new JPanel() {
      public boolean isOptimizedDrawingEnabled() {
        return false;
      }
    };
    LayoutManager overlay = new OverlayLayout(panel);
    panel.setLayout(overlay);

    JButton button = new JButton("Small");
    button.setMaximumSize(new Dimension(25, 25));
    button.setBackground(Color.white);
    button.setAlignmentX(0.5f);
    button.setAlignmentY(0.5f);    
    panel.add(button);
    
    button = new JButton("Medium");
    button.setMaximumSize(new Dimension(50, 50));
    button.setBackground(Color.gray);
    button.setAlignmentX(0.5f);
    button.setAlignmentY(0.5f);
    panel.add(button);
    
    button = new JButton("Large");
    button.setMaximumSize(new Dimension(100, 100));
    button.setBackground(Color.black);
    button.setAlignmentX(0.5f);
    button.setAlignmentY(0.5f);
    panel.add(button);    

    frame.add(panel, BorderLayout.CENTER);

    frame.setSize(400, 300);
    frame.setVisible(true);
  }
}

14.91.OverlayLayout
	14.91.1.	OverlayLayout: for layout management of components that lie on top of one another
	14.91.2.	OverlayLayout: center
	14.91.3.	OverlayLayout: alignment 0