| /************************************************************** |
| * |
| * 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 |
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| * 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 |
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| * KIND, either express or implied. See the License for the |
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| |
| |
| #ifndef INCLUDED_SLIDESHOW_EXPRESSIONNODE_HXX |
| #define INCLUDED_SLIDESHOW_EXPRESSIONNODE_HXX |
| |
| #include "animationfunction.hxx" |
| |
| |
| /* Definition of ExpressionNode interface */ |
| |
| namespace slideshow |
| { |
| namespace internal |
| { |
| /** Refinement of AnimationFunction |
| |
| This interface is used by the SMIL function parser, to |
| collapse constant values into precalculated, single nodes. |
| */ |
| class ExpressionNode : public AnimationFunction |
| { |
| public: |
| /** Predicate whether this node is constant. |
| |
| This predicate returns true, if this node is |
| neither time- nor ViewInfo dependent. This allows |
| for certain obtimizations, i.e. not the full |
| expression tree needs be represented by |
| ExpressionNodes. |
| |
| @returns true, if this node is neither time- nor |
| ViewInfo dependent |
| */ |
| virtual bool isConstant() const = 0; |
| }; |
| |
| typedef ::boost::shared_ptr< ExpressionNode > ExpressionNodeSharedPtr; |
| } |
| } |
| |
| #endif /* INCLUDED_SLIDESHOW_EXPRESSIONNODE_HXX */ |