/**
* ===========================================
* 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: HslValueFunction.java,v 1.4 2007/04/02 11:41:13 taqua Exp $
* ------------
* (C) Copyright 2006-2007, by Pentaho Corporation.
*/
package org.jfree.layouting.layouter.style.functions.values;
import org.jfree.layouting.LayoutProcess;
import org.jfree.layouting.input.style.values.CSSColorValue;
import org.jfree.layouting.input.style.values.CSSFunctionValue;
import org.jfree.layouting.input.style.values.CSSNumericType;
import org.jfree.layouting.input.style.values.CSSNumericValue;
import org.jfree.layouting.input.style.values.CSSStringValue;
import org.jfree.layouting.input.style.values.CSSValue;
import org.jfree.layouting.layouter.model.LayoutElement;
import org.jfree.layouting.layouter.style.functions.FunctionEvaluationException;
import org.jfree.layouting.layouter.style.functions.FunctionUtilities;
import org.jfree.layouting.util.ColorUtil;
/**
* Creation-Date: 16.04.2006, 14:14:42
*
* @author Thomas Morgner
*/
public class HslValueFunction implements StyleValueFunction
{
public HslValueFunction()
{
}
protected int validateHueParameter (CSSValue value) throws FunctionEvaluationException
{
final CSSNumericValue nval;
if (value instanceof CSSStringValue)
{
// I shouldn't do this, but ..
final CSSStringValue strVal = (CSSStringValue) value;
nval = FunctionUtilities.parseNumberValue(strVal.getValue());
}
else if (value instanceof CSSNumericValue == false)
{
throw new FunctionEvaluationException("Expected a number");
}
else
{
nval = (CSSNumericValue) value;
}
if (nval.getType().equals(CSSNumericType.NUMBER))
{
return (int) (nval.getValue() % 360);
}
throw new FunctionEvaluationException("Expected a number, not a length");
}
protected float validateOtherParameter (CSSValue value) throws FunctionEvaluationException
{
final CSSNumericValue nval;
if (value instanceof CSSStringValue)
{
// I shouldn't do this, but ..
final CSSStringValue strVal = (CSSStringValue) value;
nval = FunctionUtilities.parseNumberValue(strVal.getValue());
}
else if (value instanceof CSSNumericValue == false)
{
throw new FunctionEvaluationException("Expected a number");
}
else
{
nval = (CSSNumericValue) value;
}
if (nval.getType().equals(CSSNumericType.PERCENTAGE))
{
return (float) (nval.getValue() % 100);
}
throw new FunctionEvaluationException("Expected a number, not a length");
}
public CSSValue evaluate(final LayoutProcess layoutProcess,
final LayoutElement element,
final CSSFunctionValue function)
throws FunctionEvaluationException
{
final CSSValue[] values = function.getParameters();
if (values.length == 3)
{
final int hueValue = validateHueParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[0]));
final float saturationValue = validateOtherParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[1]));
final float lightValue = validateOtherParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[2]));
final float[] rgb = ColorUtil.hslToRGB
(hueValue, saturationValue, lightValue);
return new CSSColorValue(rgb[0], rgb[1], rgb[2]);
}
else if (values.length == 4)
{
final int hueValue = validateHueParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[0]));
final float saturationValue = validateOtherParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[1]));
final float lightValue = validateOtherParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[2]));
final float alphaValue = validateOtherParameter
(FunctionUtilities.resolveParameter(layoutProcess, element, values[3]));
final float[] rgb =
ColorUtil.hslToRGB(hueValue, saturationValue, lightValue);
return new CSSColorValue(rgb[0], rgb[1], rgb[2], alphaValue);
}
else
{
throw new FunctionEvaluationException("Expected either three or four parameters.");
}
}
}