| /* |
| * 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.fo.expr; |
| |
| import java.util.Stack; |
| |
| import org.apache.fop.apps.FOUserAgent; |
| import org.apache.fop.datatypes.Length; |
| import org.apache.fop.datatypes.PercentBase; |
| import org.apache.fop.fo.Constants; |
| import org.apache.fop.fo.FObj; |
| import org.apache.fop.fo.PropertyList; |
| import org.apache.fop.fo.properties.PropertyMaker; |
| |
| |
| /** |
| * This class holds context information needed during property expression |
| * evaluation. |
| * It holds the Maker object for the property, the PropertyList being |
| * built, and the FObj parent of the FObj for which the property is being set. |
| */ |
| public class PropertyInfo { |
| private PropertyMaker maker; |
| private PropertyList plist; |
| private FObj fo; |
| private Stack stkFunction; // Stack of functions being evaluated |
| |
| /** |
| * Constructor |
| * @param maker Property.Maker object |
| * @param plist PropertyList object |
| */ |
| public PropertyInfo(PropertyMaker maker, PropertyList plist) { |
| this.maker = maker; |
| this.plist = plist; |
| this.fo = plist.getParentFObj(); |
| } |
| |
| /** |
| * Return the PercentBase object used to calculate the absolute value from |
| * a percent specification. |
| * Propagates to the Maker. |
| * @return The PercentBase object or null if percentLengthOK()=false. |
| */ |
| public PercentBase getPercentBase() throws PropertyException { |
| PercentBase pcbase = getFunctionPercentBase(); |
| return (pcbase != null) ? pcbase : maker.getPercentBase(plist); |
| } |
| |
| /** |
| * @return the current font-size value as base units (milli-points). |
| */ |
| public Length currentFontSize() throws PropertyException { |
| return plist.get(Constants.PR_FONT_SIZE).getLength(); |
| } |
| |
| /** |
| * accessor for FObj |
| * @return FObj |
| */ |
| public FObj getFO() { |
| return fo; |
| } |
| |
| /** |
| * accessor for PropertyList |
| * @return PropertyList object |
| */ |
| public PropertyList getPropertyList() { |
| return plist; |
| } |
| |
| /** |
| * accessor for PropertyMaker |
| * @return PropertyMaker object |
| */ |
| public PropertyMaker getPropertyMaker() { |
| return maker; |
| } |
| |
| /** |
| * push a function onto the function stack |
| * @param func function to push onto stack |
| */ |
| public void pushFunction(Function func) { |
| if (stkFunction == null) { |
| stkFunction = new Stack(); |
| } |
| stkFunction.push(func); |
| } |
| |
| /** |
| * pop a function off of the function stack |
| */ |
| public void popFunction() { |
| if (stkFunction != null) { |
| stkFunction.pop(); |
| } |
| } |
| |
| /** |
| * Convenience shortcut to get a reference to the FOUserAgent |
| * |
| * @return the FOUserAgent |
| */ |
| protected FOUserAgent getUserAgent() { |
| return (plist.getFObj() != null) |
| ? plist.getFObj().getUserAgent() |
| : null; |
| } |
| |
| private PercentBase getFunctionPercentBase() { |
| if (stkFunction != null) { |
| Function f = (Function)stkFunction.peek(); |
| if (f != null) { |
| return f.getPercentBase(); |
| } |
| } |
| return null; |
| } |
| |
| } |