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) 
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 * 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,
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/* $Id: Numeric.java 1805173 2017-08-16 10:50:04Z ssteiner $ */

package org.apache.fop.datatypes;


An interface for classes that can participate in numeric operations.
All the numeric operation (+, -, *, ...) are expressed in terms of
this Numeric interface.
Numerics has a value (getNumericValue) and a dimension (getDimension).
Numerics can be either absolute or relative. Relative numerics
must be resolved against base value before the value can be used.


To support relative numerics internally in the expression parser and
during evaluation one additional methods exists: isAbsolute() which
return true for absolute numerics and false for relative numerics.

/**
 * An interface for classes that can participate in numeric operations.
 * All the numeric operation (+, -, *, ...) are expressed in terms of
 * this Numeric interface.
 * Numerics has a value (getNumericValue) and a dimension (getDimension).
 * Numerics can be either absolute or relative. Relative numerics
 * must be resolved against base value before the value can be used.
 * <p>
 * To support relative numerics internally in the expression parser and
 * during evaluation one additional methods exists: isAbsolute() which
 * return true for absolute numerics and false for relative numerics.
 */
public interface Numeric {
    
Return the value of this Numeric

Returns:the computed value.
/**
     * Return the value of this Numeric
     * @return the computed value.
     */
    double getNumericValue();

    
Return the value of this Numeric

Params:
  • context – The context for the length calculation (for percentage based lengths)
Returns:the computed value.
/**
     * Return the value of this Numeric
     * @param context The context for the length calculation (for percentage based lengths)
     * @return the computed value.
     */
    double getNumericValue(PercentBaseContext context);

    
Return the dimension of this numeric. Plain numbers has a dimension of
0 and length has a dimension of 1. Other dimension can occur as a result
of multiplications and divisions.

Returns:the dimension.
/**
     * Return the dimension of this numeric. Plain numbers has a dimension of
     * 0 and length has a dimension of 1. Other dimension can occur as a result
     * of multiplications and divisions.
     * @return the dimension.
     */
    int getDimension();

    
Return true if the numeric is an absolute value. Relative values are
percentages and table-column-units. All other numerics are absolute.

Returns:true when the numeric is absolute.
/**
     * Return true if the numeric is an absolute value. Relative values are
     * percentages and table-column-units. All other numerics are absolute.
     * @return true when the numeric is absolute.
     */
    boolean isAbsolute();

    
Returns the value of this numeric as an int.

Returns:the value as an integer.
/**
     * Returns the value of this numeric as an int.
     * @return the value as an integer.
     */
    int getValue();

    
Returns the value of this numeric as an int.

Params:
  • context – the context for the length calculation (for percentage based lengths)
Returns:the value as an integer.
/**
     * Returns the value of this numeric as an int.
     * @param context the context for the length calculation (for percentage based lengths)
     * @return the value as an integer.
     */
    int getValue(PercentBaseContext context);

    /**
     * Return the resolved value. This method will be called during evaluation
     * of the expression tree and relative numerics can then return a
     * resolved absolute Numeric. Absolute numerics can just return themselves.
     *
     * @return A resolved value.
     * @throws PropertyException
     */
    //Numeric getResolved() throws PropertyException;

    
Return the enum value that is stored in this numeric.

Returns:the enum value
/**
     * Return the enum value that is stored in this numeric.
     * @return the enum value
     */
    int getEnum();
}