| /* |
| * 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. |
| */ |
| |
| /* $Id$ */ |
| |
| package org.apache.fop.datatypes; |
| |
| import org.apache.fop.fo.expr.PropertyException; |
| |
| /** |
| * 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 expresion parser and |
| * during evaulation 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 |
| * @return the computed value. |
| * @throws PropertyException |
| */ |
| double getNumericValue() throws PropertyException; |
| |
| /** |
| * Return the value of this Numeric |
| * @param context The context for the length calculation (for percentage based lengths) |
| * @return the computed value. |
| * @throws PropertyException |
| */ |
| double getNumericValue(PercentBaseContext context) throws PropertyException; |
| |
| /** |
| * 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. |
| * @return true when the numeric is absolute. |
| */ |
| boolean isAbsolute(); |
| |
| /** |
| * Returns the value of this numeric as an int. |
| * @return the value as an integer. |
| */ |
| public int getValue(); |
| |
| /** |
| * 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. |
| */ |
| public int getValue(PercentBaseContext context); |
| |
| /** |
| * Return the resolved value. This method will becalled during evaluation |
| * of the expression tree and relative numerics can then return a |
| * resolved absolute Numeric. Absolute numerics can just return themself. |
| * |
| * @return A resolved value. |
| * @throws PropertyException |
| */ |
| //Numeric getResolved() throws PropertyException; |
| |
| /** |
| * Return the enum value that is stored in this numeric. |
| */ |
| public int getEnum(); |
| } |