CheckBoxBorderPanel.java

package jas.util;

import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.LayoutManager;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.Border;
/**
 * A JPanel which has a checkbox embedded in its border. The contents of the panel
 * are automatically insensitized when the checkbox is turned off.
 */
public class CheckBoxBorderPanel extends JPanel implements ItemListener
{
	public CheckBoxBorderPanel(String title)
	{
		this(title,null,null);
	}
	public CheckBoxBorderPanel(String title, Border border)
	{
		this(title,border,null);
	}
	public CheckBoxBorderPanel(String title, LayoutManager layout)
	{
		this(title,null,layout);
	}
	public CheckBoxBorderPanel(String title, Border border, LayoutManager layout)
	{
		if (layout == null) layout = new FlowLayout();
		if (border == null) border = BorderFactory.createEtchedBorder();
		
		checkbox = new JCheckBox(title);
		setLayout(layout);
		setBorder(border);
		add(checkbox,0);
		checkbox.addItemListener(this);
	}
	public void doLayout()
	{
		setEnabled();
		checkbox.setVisible(false);
		super.doLayout();
		checkbox.setVisible(true);
		Dimension size = checkbox.getPreferredSize();
		checkbox.setSize(size);
		checkbox.setLocation(20,0);
	}
	public void itemStateChanged(ItemEvent e)
	{
		setEnabled();
	}
	private void setEnabled()
	{
		boolean set = checkbox.isSelected();
		Component[] children = getComponents();
		for (int i=0; i<children.length; i++) 
			if (children[i] != checkbox) children[i].setEnabled(set);
	}
	public void setBorder(Border border)
	{
		super.setBorder(border == null ? null : new CBBorder(border));
	}
	public JCheckBox getCheckBox()
	{
		return checkbox;
	}
	private JCheckBox checkbox;

	private class CBBorder implements Border
	{
		CBBorder(Border child)
		{
			this.child = child;
		}		
		public Insets getBorderInsets(Component c)
		{
			Insets result = (Insets) child.getBorderInsets(c).clone();
			result.top = checkbox.getPreferredSize().height;
			return result;
		}

		public boolean isBorderOpaque()
		{
			return false;
		}

		public void paintBorder(Component c, Graphics g, int x, int y, int width, int height)
		{
			int cHeight = checkbox.getPreferredSize().height/2;
			y += cHeight;
			height -= cHeight;
			child.paintBorder(c,g,x,y,width,height);
		}
		private Border child;
	}
	public static void main(String[] argv)
	{
		JFrame frame = new JFrame();
		CheckBoxBorderPanel p = new CheckBoxBorderPanel("test");
		p.add(new JButton("Test"));
		frame.setContentPane(p);
		frame.setSize(200,200);
		frame.show();
	}
}