/**
* ===========================================
* LibLayout : a free Java layouting library
* ===========================================
*
* Project Info: http://reporting.pentaho.org/liblayout/
*
* (C) Copyright 2006-2007, by Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------
* $Id: ColorUtil.java 6653 2008-12-02 14:53:40Z tmorgner $
* ------------
* (C) Copyright 2006-2007, by Pentaho Corporation.
*/
package org.jfree.layouting.util;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import org.jfree.layouting.input.style.keys.color.CSSSystemColors;
import org.jfree.layouting.input.style.keys.color.HtmlColors;
import org.jfree.layouting.input.style.keys.color.SVGColors;
import org.jfree.layouting.input.style.values.CSSColorValue;
import org.jfree.layouting.input.style.values.CSSValue;
/**
* Creation-Date: 16.04.2006, 15:23:58
*
* @author Thomas Morgner
*/
public class ColorUtil
{
private ColorUtil()
{
}
private static final float ONE_THIRD = 1f / 3f;
/*
* HOW TO RETURN hsl.to.rgb(h, s, l):
SELECT:
l<=0.5: PUT l*(s+1) IN m2
ELSE: PUT l+s-l*s IN m2
PUT l*2-m2 IN m1
PUT hue.to.rgb(m1, m2, h+1/3) IN r
PUT hue.to.rgb(m1, m2, h ) IN g
PUT hue.to.rgb(m1, m2, h-1/3) IN b
RETURN (r, g, b)
HOW TO RETURN hue.to.rgb(m1, m2, h):
IF h<0: PUT h+1 IN h
IF h>1: PUT h-1 IN h
IF h*6<1: RETURN m1+(m2-m1)*h*6
IF h*2<1: RETURN m2
IF h*3<2: RETURN m1+(m2-m1)*(2/3-h)*6
RETURN m1
*/
public static float[] hslToRGB (final int h, final float s, final float l)
{
final int hue = normalizeHue(h);
float saturation = s;
if (saturation > 100)
{
saturation = 100;
}
if (saturation < 0)
{
saturation = 0;
}
float lightness = l;
if (lightness > 100)
{
lightness = 100;
}
if (lightness < 0)
{
lightness = 0;
}
final float m2;
if (lightness <= 0.5)
{
m2 = lightness * (saturation + 1);
}
else
{
m2 = lightness + saturation - lightness * saturation;
}
final float m1 = lightness * 2 - m2;
final float r = hueToRGB(m1, m2, hue + ONE_THIRD);
final float g = hueToRGB(m1, m2, hue);
final float b = hueToRGB(m1, m2, hue - ONE_THIRD);
return new float[]{r, g, b};
}
private static float hueToRGB(final float m1, final float m2, float h)
{
if (h < 0)
{
h = h + 1;
}
if (h > 1)
{
h = h - 1;
}
if ((h * 6f) < 1)
{
return m1 + (m2 - m1) * h * 6;
}
if ((h * 2f) < 1)
{
return m2;
}
if ((h * 3f) < 2)
{
return m1 + (m2 - m1) * (2 * ONE_THIRD - h) * 6;
}
return m1;
}
private static int normalizeHue(final int integerValue)
{
return ((integerValue % 360) + 360) % 360;
}
public static CSSValue parseColor(String colorSpec)
{
final CSSValue color = parseIdentColor(colorSpec);
if (color != null)
{
return color;
}
try
{
if (colorSpec.length() == 4) // #rgb
{
colorSpec = "#" + colorSpec.charAt(1) + colorSpec.charAt(1) +
colorSpec.charAt(2) + colorSpec.charAt(2) +
colorSpec.charAt(3) + colorSpec.charAt(3);
}
final Integer decoded = Integer.decode(colorSpec);
return new CSSColorValue(decoded.intValue(), false);
}
catch(Exception e)
{
return null;
}
}
public static CSSValue parseIdentColor(final String name)
{
if (CSSSystemColors.CURRENT_COLOR.getCSSText().equalsIgnoreCase(name))
{
return CSSSystemColors.CURRENT_COLOR;
}
final CSSColorValue htmlColors = parseColorFromClass(name, HtmlColors.class);
if (htmlColors != null)
{
return htmlColors;
}
final CSSColorValue svgColors = parseColorFromClass(name, SVGColors.class);
if (svgColors != null)
{
return svgColors;
}
final CSSColorValue systemColors = parseColorFromClass(name,
CSSSystemColors.class);
if (systemColors != null)
{
return systemColors;
}
//Log.debug("No such constant: " + name);
return null;
}
private static CSSColorValue parseColorFromClass(final String name, final Class c)
{
// try to get a color by name using reflection
final Field[] f = c.getFields();
for (int i = 0; i < f.length; i++)
{
try
{
final Field field = f[i];
if (field.getName().equalsIgnoreCase(name) == false)
{
continue;
}
if (CSSColorValue.class.isAssignableFrom(field.getType()) == false)
{
continue;
}
if (Modifier.isPublic(field.getModifiers()) &&
Modifier.isStatic((field.getModifiers())))
{
return (CSSColorValue) field.get(null);
}
}
catch (Exception ce)
{
// we ignore exceptions here.
}
}
return null;
}
}