http://xmlgraphics.apache.org/fop/: Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF. (Apache Software Foundation) 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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: PercentBase.java 679326 2008-07-24 09:35:34Z vhennebert $ */

package org.apache.fop.datatypes;

import org.apache.fop.fo.expr.PropertyException;


Interface for objects that can be used as base objects for percentage
computations

/**
 * Interface for objects that can be used as base objects for percentage
 * computations
 */
public interface PercentBase {

    
Determines whether a numeric property is created or one with a percentage
base.

Returns:0 for length, 1 for percentage
/**
     * Determines whether a numeric property is created or one with a percentage
     * base.
     * @return 0 for length, 1 for percentage
     */
    int getDimension();

    
Returns:the base value (this will be used as the base to which a percentage will be
        applied to compute the length of the referencing item)
/**
     * @return the base value (this will be used as the base to which a percentage will be
     *         applied to compute the length of the referencing item)
     */
    double getBaseValue();

    
Params:
  • context – The context for percentage evaluation
Throws:
Returns:the integer size in millipoints of the object (this will be used
as the base to which a percentage will be applied to compute the length
of the referencing item)
/**
     * @param context The context for percentage evaluation
     * @return the integer size in millipoints of the object (this will be used
     * as the base to which a percentage will be applied to compute the length
     * of the referencing item)
     * @throws PropertyException if a problem occurs during evaluation of this
     *     value.
     */
    int getBaseLength(PercentBaseContext context) throws PropertyException;

}