/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id$ */
package org.apache.fop.fo.expr;
import org.apache.fop.datatypes.PercentBaseContext;
import org.apache.fop.datatypes.PercentBase;
import org.apache.fop.fo.properties.ColorTypeProperty;
import org.apache.fop.fo.properties.Property;
class RGBColorFunction extends FunctionBase {
public int nbArgs() {
return 3;
}
/**
* Return an object which implements the PercentBase interface.
* Percents in arguments to this function are interpreted relative
* to 255.
*/
public PercentBase getPercentBase() {
return new RGBPercentBase();
}
public Property eval(Property[] args,
PropertyInfo pInfo) throws PropertyException {
// Using CSS rules, numbers are either supposed to be 0-255
// or percentage values. If percentages value, they've already
// been converted to reals.
float[] cfvals = new float[3]; // RGB
for (int i = 0; i < 3; i++) {
Number cval = args[i].getNumber();
if (cval == null) {
throw new PropertyException("Argument to rgb() must be a Number");
}
float colorVal = cval.floatValue() / 255f;
if (colorVal < 0.0 || colorVal > 255.0) {
throw new PropertyException(
"Arguments to rgb() must normalize to the range 0 to 1");
}
cfvals[i] = colorVal;
}
return new ColorTypeProperty(cfvals[0], cfvals[1], cfvals[2]);
}
static class RGBPercentBase implements PercentBase {
public int getDimension() {
return 0;
}
public double getBaseValue() {
return 255f;
}
public int getBaseLength(PercentBaseContext context) {
return 0;
}
}
}