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cdesktop/cde/lib/DtMmdb/StyleSheet/Renderer.h

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/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* $XConsortium: Renderer.h /main/3 1996/06/11 17:08:07 cde-hal $ */
#ifndef _Renderer_h
#define _Renderer_h 1
#include "Feature.h"
#include "dti_excs/Exceptions.hh"
/* **************************************************************
* class Renderer
the Renderer is responsible for taking the style sheet features
matched with an ELEMENT and using them to guide the drawing of the
ELEMENT data on the page
************************************************************** */
/* **************************************************************
The symbol table supplied is common to the Node Parser,
Style Sheet parser and the Renderer.
* ************************************************************** */
//class FeatureSet;
class Renderer : public Destructable
{
public:
Renderer() {};
virtual ~Renderer() {};
virtual FeatureSet *initialize() = 0; /* return default feature set */
/* -------- Begin Element -------- */
/* ************************************************************
* called when a new ELEMENT is found in the document
* FeatureSet is set of features and values that match with the
* ELEMENT as described in the style sheet
* ************************************************************ */
/* returns a non-zero value if element is to be ignored */
virtual unsigned int
BeginElement(const Element &element,
const FeatureSet &featureset,
const FeatureSet &complete,
const FeatureSet &parentComplete) = 0;
/* -------- Data -------- */
/* ************************************************************
* ELEMENT data passed in (usually text to be displayed)
* embedded ELEMENT children are passed in with BeginElement...
* ************************************************************ */
virtual void
data(const char *data, unsigned int size) = 0;
/* -------- End Element -------- */
/* ************************************************************
* End of ELEMENT processing (eg. postfixes, reset pointers etc.)
* ************************************************************ */
virtual void
EndElement(const Symbol &element_name) = 0 ;
/* ************************************************************
* Called BEFORE any data processing begins
* ************************************************************ */
virtual void Begin() = 0;
/* **************************************************************
* called after all data has been processed
* ************************************************************** */
virtual void End() = 0;
// These two functions allow a renderer to set up internal variable table.
/* **************************************************************
* pass a variable and a Expression to the renderer and let it decide
* whether to accept the variable and the Expression and put them into
* the internal variable table.
*
* non zero return value means that it has been entered into the internal
* table
*
* If gRenderer is set to null while style sheet is parsed, the
* accept() function will not be called from style.y.
* ************************************************************** */
virtual unsigned int accept(const char*, const Expression*) { return 0 ;}
/* ************************************************************
*
* evaluate the variable to a FeatureValue
*
* If gRenderer is set to null while the renderer is running, the
* evaluate() function will not be called.
* ************************************************************ */
virtual FeatureValue* evaluate(const char*) { return 0 ; }
/* **************************************************************
* notifies renderer that the local feature set will be evaluated.
* ************************************************************** */
virtual void preEvaluate(const Element &) {}
/* **************************************************************
* notifies renderer that the local feature set has been evaluated.
* ************************************************************** */
virtual void postEvaluate(const Element &) {}
protected:
};
#endif