BoxHighlightPainter.java

/*******************************************************************************
 * Copyright (c) 2015 Jeff Martin.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public
 * License v3.0 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 *
 * Contributors:
 * Jeff Martin - initial API and implementation
 ******************************************************************************/
package cuchaz.enigma.gui;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.Shape;

import javax.swing.text.BadLocationException;
import javax.swing.text.Highlighter;
import javax.swing.text.JTextComponent;

public abstract class BoxHighlightPainter implements
	Highlighter.HighlightPainter
{
	
	private Color m_fillColor;
	private Color m_borderColor;
	
	protected BoxHighlightPainter(Color fillColor, Color borderColor)
	{
		m_fillColor = fillColor;
		m_borderColor = borderColor;
	}
	
	@Override
	public void paint(Graphics g, int start, int end, Shape shape,
		JTextComponent text)
	{
		Rectangle bounds = getBounds(text, start, end);
		
		// fill the area
		if(m_fillColor != null)
		{
			g.setColor(m_fillColor);
			g.fillRoundRect(bounds.x, bounds.y, bounds.width, bounds.height, 4,
				4);
		}
		
		// draw a box around the area
		g.setColor(m_borderColor);
		g.drawRoundRect(bounds.x, bounds.y, bounds.width, bounds.height, 4, 4);
	}
	
	protected static Rectangle getBounds(JTextComponent text, int start, int end)
	{
		try
		{
			// determine the bounds of the text
			Rectangle bounds =
				text.modelToView(start).union(text.modelToView(end));
			
			// adjust the box so it looks nice
			bounds.x -= 2;
			bounds.width += 2;
			bounds.y += 1;
			bounds.height -= 2;
			
			return bounds;
		}catch(BadLocationException ex)
		{
			// don't care... just return something
			return new Rectangle(0, 0, 0, 0);
		}
	}
}