/*  					W3C Sample Code Library libwww Rich Hypertext Object!  HyperText Object Builder!*//***	(c) COPYRIGHT MIT 1995.**	Please first read the full copyright statement in the file COPYRIGH.*//*This is the interface that  you can use to build a parsed HTML object(called an hypertext object) as output of the libwwwHTML parser. It is based on callback functions that the application canregister as needed in order to get the various events out of the HTML parser.These are the different events that can be registered:	 	   o 	     When parsing is about to start or terminate  o 	     When a chunk of plain text has been found  o 	     When a link has been found in some HTML element  o 	     When an HTML element is about to start or end  o 	     Handler for unparsed elements  o 	     Handler for unparsed entities	 Building an hypertext object can contain references to stylesheets. Libwwwdoesn't come with a stylesheet implementation but it does have ageneric stylesheet manager which can be used forregistering and looking up styles. As an example, you can see how the libwwwrobot uses the link callout whereasthe Line Mode Browser has a completeimplementation in the GridText module.*/#ifndef HTEXT_H#define HTEXT_H#include "HTAnchor.h"#include "HTStream.h"/*.  The HText Object.The HText object is only known as a name to libwww - it isn't definedor used anywhere as an actual structure. The application can use the HTextobject to contain the information needed to build a parsed object - a hypertextobject - as data arrives from the libwww HTML parser.When a HText object is to be created, this module calls out to any registeredcreation method and in turn uses the newly created HText object in everysubsequent call to any registered callback routine as the HTML stream isparsed.*/typedef struct _HText HText;/*.  Callback for Creating and Deleting an HText Object.When an HTML stream is created, theHTML parser checks to see if there are any callbacksregistered for handling the HText object. If this isthe case then the creation callback is called so that the application cancreate a new HText object. After that the various callbacksare called (if registered) as text comes in andgets parsed.*/typedef HText * HText_new (	HTRequest *		request,	HTParentAnchor *	anchor,	HTStream *		output_stream);typedef BOOL HText_delete (HText * me);/*(  Register Creation/Deletion Callbacks)*/extern BOOL HText_registerCDCallback (HText_new *, HText_delete *);extern BOOL HText_unregisterCDCallback (void);/*.  Callback for Start and Terminate Parsing.The call sequence is the following: First HText_build is calledwith the status of HTEXT_BEGIN, then any combination of other appendcalls, and at the end HText_build is called with the terminationstatus - if it terminated normally then the status is HTEXT_END,if the download was aborted the status is HTEXT_ABORT.*/typedef enum _HTextStatus {    HTEXT_BEGIN,    HTEXT_END,    HTEXT_ABORT} HTextStatus;typedef void HText_build (HText * text, HTextStatus status);/*(  Register Start/End Callback)*/extern BOOL HText_registerBuildCallback (HText_build *);extern BOOL HText_unregisterBuildCallback (void);/*.  Callback for Handling Chunks of Text.THE STRING IS NOT ZERO-TERMINATED!!! When plain text isfound then it can be passed to the application via this function. HTML textis already stripped for unneeded white space whereas literal text isn't.The text is of course to be taken "relative" to which element is is foundwithin - this is not checked by the HTML parser but can be checked by theapplication by using the Element callback function.*/typedef void HText_addText (	HText * 	text,	const char * 	buffer,	int		length);/*(  Register Text Callback)*/extern BOOL HText_registerTextCallback (HText_addText *);extern BOOL HText_unregisterTextCallback (void);/*.  Callback for Handling Hypertext Links.Whenever a link is found in the HTML stream, be it from an anchor element,an inlined image, etc. then it is picked up and this called out to this functionwith the parameters necessary to be able to see what type of link it is (theelement and the name of the attribute where it was found). The element numberand attribute number are integers that are defined by theHTML DTD used by the HTMl parser. Thepresent and value arrays contains all theSGML attributes and values found in the elementuntouched. Again, the array is defined by the HTMLDTD used by the HTML parser.*/typedef void HText_foundLink (	HText * 	text,	int		element_number,	int		attribute_number,	HTChildAnchor *	anchor,	const BOOL *	present,	const char **	value);/*(  Register Link Callback)*/extern BOOL HText_registerLinkCallback (HText_foundLink *);extern BOOL HText_unregisterLinkCallback (void);/*.  Callback for Handling HTML Elements.Whenever an element is found in the HTML stream, be it an IMG element, aBODY element, etc. then it is picked up and this called out to this functionwith the parameters necessary to be able to see what type of element it is.The element number and attribute number are integers that are defined bythe HTML DTD used by the HTMl parser. Thepresent and value arrays contains all theSGML attributes and values found in the elementuntouched. Again, the array is defined by the HTMLDTD used by the HTML parser.*/typedef void HText_beginElement (	HText * 	text,	int		element_number,	const BOOL *	present,	const char **	value);typedef void HText_endElement (	HText * 	text,	int		element_number);/*(  Register HTML Element Callback)*/extern BOOL HText_registerElementCallback (HText_beginElement *, HText_endElement *);extern BOOL HText_unregisterElementCallback (void);/*.  Callback for Unparsed Elements.Whenever an element is found which is not known by the HTML DTD, then theinformation is passed to the unparsed element handlers.*/typedef void HText_unparsedBeginElement (	HText *		HText,	const char * 	buffer,	int		length);typedef void HText_unparsedEndElement (	HText *		HText,	const char * 	buffer,	int		length);/*(  Register Unparsed Element Callback)*/extern BOOL HText_registerUnparsedElementCallback (	HText_unparsedBeginElement *,	HText_unparsedEndElement *);extern BOOL HText_unregisterUnparsedElementCallback (void);/*.  Callback for Unparsed Entity.Whenever an entity is found which is not known by the HTML DTD, then theinformation is passed to the default handler.*/typedef void HText_unparsedEntity (	HText *		HText,	const char * 	buffer,	int		length);/*(  Register Unparsed Entity Callback)*/extern BOOL HText_registerUnparsedEntityCallback (HText_unparsedEntity *);extern BOOL HText_unregisterUnparsedEntityCallback (void);/**/#endif /* HTEXT_H *//*    @(#) $Id: HText.html,v 2.32 1999/01/06 15:38:48 frystyk Exp $*/