1*aaef562fSAndrew Rist /************************************************************** 2cdf0e10cSrcweir * 3*aaef562fSAndrew Rist * Licensed to the Apache Software Foundation (ASF) under one 4*aaef562fSAndrew Rist * or more contributor license agreements. See the NOTICE file 5*aaef562fSAndrew Rist * distributed with this work for additional information 6*aaef562fSAndrew Rist * regarding copyright ownership. The ASF licenses this file 7*aaef562fSAndrew Rist * to you under the Apache License, Version 2.0 (the 8*aaef562fSAndrew Rist * "License"); you may not use this file except in compliance 9*aaef562fSAndrew Rist * with the License. You may obtain a copy of the License at 10*aaef562fSAndrew Rist * 11*aaef562fSAndrew Rist * http://www.apache.org/licenses/LICENSE-2.0 12*aaef562fSAndrew Rist * 13*aaef562fSAndrew Rist * Unless required by applicable law or agreed to in writing, 14*aaef562fSAndrew Rist * software distributed under the License is distributed on an 15*aaef562fSAndrew Rist * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*aaef562fSAndrew Rist * KIND, either express or implied. See the License for the 17*aaef562fSAndrew Rist * specific language governing permissions and limitations 18*aaef562fSAndrew Rist * under the License. 19*aaef562fSAndrew Rist * 20*aaef562fSAndrew Rist *************************************************************/ 21*aaef562fSAndrew Rist 22*aaef562fSAndrew Rist 23cdf0e10cSrcweir 24cdf0e10cSrcweir #ifndef INCLUDED_SLIDESHOW_EXPRESSIONNODE_HXX 25cdf0e10cSrcweir #define INCLUDED_SLIDESHOW_EXPRESSIONNODE_HXX 26cdf0e10cSrcweir 27cdf0e10cSrcweir #include "animationfunction.hxx" 28cdf0e10cSrcweir 29cdf0e10cSrcweir 30cdf0e10cSrcweir /* Definition of ExpressionNode interface */ 31cdf0e10cSrcweir 32cdf0e10cSrcweir namespace slideshow 33cdf0e10cSrcweir { 34cdf0e10cSrcweir namespace internal 35cdf0e10cSrcweir { 36cdf0e10cSrcweir /** Refinement of AnimationFunction 37cdf0e10cSrcweir 38cdf0e10cSrcweir This interface is used by the SMIL function parser, to 39cdf0e10cSrcweir collapse constant values into precalculated, single nodes. 40cdf0e10cSrcweir */ 41cdf0e10cSrcweir class ExpressionNode : public AnimationFunction 42cdf0e10cSrcweir { 43cdf0e10cSrcweir public: 44cdf0e10cSrcweir /** Predicate whether this node is constant. 45cdf0e10cSrcweir 46cdf0e10cSrcweir This predicate returns true, if this node is 47cdf0e10cSrcweir neither time- nor ViewInfo dependent. This allows 48cdf0e10cSrcweir for certain obtimizations, i.e. not the full 49cdf0e10cSrcweir expression tree needs be represented by 50cdf0e10cSrcweir ExpressionNodes. 51cdf0e10cSrcweir 52cdf0e10cSrcweir @returns true, if this node is neither time- nor 53cdf0e10cSrcweir ViewInfo dependent 54cdf0e10cSrcweir */ 55cdf0e10cSrcweir virtual bool isConstant() const = 0; 56cdf0e10cSrcweir }; 57cdf0e10cSrcweir 58cdf0e10cSrcweir typedef ::boost::shared_ptr< ExpressionNode > ExpressionNodeSharedPtr; 59cdf0e10cSrcweir } 60cdf0e10cSrcweir } 61cdf0e10cSrcweir 62cdf0e10cSrcweir #endif /* INCLUDED_SLIDESHOW_EXPRESSIONNODE_HXX */ 63