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- /////////////////////////////////////////////////////////////////////////////
- // Name: htmlpars.h
- // Purpose: wx28HtmlParser class (generic parser)
- // Author: Vaclav Slavik
- // Copyright: (c) 1999 Vaclav Slavik
- // Licence: wxWindows licence
- /////////////////////////////////////////////////////////////////////////////
- #ifndef _WX_HTMLPARS_H_
- #define _WX_HTMLPARS_H_
- #include "wx/defs.h"
- #include "wx/filesys.h"
- #include "wx/hash.h"
- #include "wx/fontenc.h"
- #include "htmltag.h"
- class wxMBConv;
- class wx28HtmlParser;
- class wx28HtmlTagHandler;
- class wx28HtmlEntitiesParser;
- class wx28HtmlTextPieces;
- class wx28HtmlParserState;
- enum wx28HtmlURLType
- {
- wxHTML_URL_PAGE,
- wxHTML_URL_IMAGE,
- wxHTML_URL_OTHER
- };
- // This class handles generic parsing of HTML document : it scans
- // the document and divides it into blocks of tags (where one block
- // consists of starting and ending tag and of text between these
- // 2 tags.
- class wx28HtmlParser : public wxObject
- {
- DECLARE_ABSTRACT_CLASS(wx28HtmlParser)
- public:
- wx28HtmlParser();
- virtual ~wx28HtmlParser();
- // Sets the class which will be used for opening files
- void SetFS(wxFileSystem *fs) { m_FS = fs; }
- wxFileSystem* GetFS() const { return m_FS; }
- // Opens file if the parser is allowed to open given URL (may be forbidden
- // for security reasons)
- virtual wxFSFile *OpenURL(wx28HtmlURLType type, const wxString& url) const;
- // You can simply call this method when you need parsed output.
- // This method does these things:
- // 1. call InitParser(source);
- // 2. call DoParsing();
- // 3. call GetProduct(); (its return value is then returned)
- // 4. call DoneParser();
- wxObject* Parse(const wxString& source);
- // Sets the source. This must be called before running Parse() method.
- virtual void InitParser(const wxString& source);
- // This must be called after Parse().
- virtual void DoneParser();
- // May be called during parsing to immediately return from Parse().
- virtual void StopParsing() { m_stopParsing = true; }
- // Parses the m_Source from begin_pos to end_pos-1.
- // (in noparams version it parses whole m_Source)
- void DoParsing(int begin_pos, int end_pos);
- void DoParsing();
- // Returns pointer to the tag at parser's current position
- wx28HtmlTag *GetCurrentTag() const { return m_CurTag; }
- // Returns product of parsing
- // Returned value is result of parsing of the part. The type of this result
- // depends on internal representation in derived parser
- // (see wx28HtmlWinParser for details).
- virtual wxObject* GetProduct() = 0;
- // adds handler to the list & hash table of handlers.
- virtual void AddTagHandler(wx28HtmlTagHandler *handler);
- // Forces the handler to handle additional tags (not returned by GetSupportedTags).
- // The handler should already be in use by this parser.
- // Example: you want to parse following pseudo-html structure:
- // <myitems>
- // <it name="one" value="1">
- // <it name="two" value="2">
- // </myitems>
- // <it> This last it has different meaning, we don't want it to be parsed by myitems handler!
- // handler can handle only 'myitems' (e.g. its GetSupportedTags returns "MYITEMS")
- // you can call PushTagHandler(handler, "IT") when you find <myitems>
- // and call PopTagHandler() when you find </myitems>
- void PushTagHandler(wx28HtmlTagHandler *handler, const wxString& tags);
- // Restores state before last call to PushTagHandler
- void PopTagHandler();
- wxString* GetSource() {return &m_Source;}
- void SetSource(const wxString& src);
- // Sets HTML source and remembers current parser's state so that it can
- // later be restored. This is useful for on-line modifications of
- // HTML source (for example, <pre> handler replaces spaces with
- // and newlines with <br>)
- virtual void SetSourceAndSaveState(const wxString& src);
- // Restores parser's state from stack or returns false if the stack is
- // empty
- virtual bool RestoreState();
- // Returns HTML source inside the element (i.e. between the starting
- // and ending tag)
- wxString GetInnerSource(const wx28HtmlTag& tag);
- // Parses HTML string 'markup' and extracts charset info from <meta> tag
- // if present. Returns empty string if the tag is missing.
- // For wxHTML's internal use.
- static wxString ExtractCharsetInformation(const wxString& markup);
- // Returns entity parser object, used to substitute HTML &entities;
- wx28HtmlEntitiesParser *GetEntitiesParser() const { return m_entitiesParser; }
- protected:
- // DOM structure
- void CreateDOMTree();
- void DestroyDOMTree();
- void CreateDOMSubTree(wx28HtmlTag *cur,
- int begin_pos, int end_pos,
- wx28HtmlTagsCache *cache);
- // Adds text to the output.
- // This is called from Parse() and must be overridden in derived classes.
- // txt is not guaranteed to be only one word. It is largest continuous part of text
- // (= not broken by tags)
- // NOTE : using char* because of speed improvements
- virtual void AddText(const wxChar* txt) = 0;
- // Adds tag and proceeds it. Parse() may (and usually is) called from this method.
- // This is called from Parse() and may be overridden.
- // Default behaviour is that it looks for proper handler in m_Handlers. The tag is
- // ignored if no hander is found.
- // Derived class is *responsible* for filling in m_Handlers table.
- virtual void AddTag(const wx28HtmlTag& tag);
- protected:
- // DOM tree:
- wx28HtmlTag *m_CurTag;
- wx28HtmlTag *m_Tags;
- wx28HtmlTextPieces *m_TextPieces;
- size_t m_CurTextPiece;
- wxString m_Source;
- wx28HtmlParserState *m_SavedStates;
- // handlers that handle particular tags. The table is accessed by
- // key = tag's name.
- // This attribute MUST be filled by derived class otherwise it would
- // be empty and no tags would be recognized
- // (see wx28HtmlWinParser for details about filling it)
- // m_HandlersHash is for random access based on knowledge of tag name (BR, P, etc.)
- // it may (and often does) contain more references to one object
- // m_HandlersList is list of all handlers and it is guaranteed to contain
- // only one reference to each handler instance.
- wxList m_HandlersList;
- wxHashTable m_HandlersHash;
- DECLARE_NO_COPY_CLASS(wx28HtmlParser)
- // class for opening files (file system)
- wxFileSystem *m_FS;
- // handlers stack used by PushTagHandler and PopTagHandler
- wxList *m_HandlersStack;
- // entity parse
- wx28HtmlEntitiesParser *m_entitiesParser;
- // flag indicating that the parser should stop
- bool m_stopParsing;
- };
- // This class (and derived classes) cooperates with wx28HtmlParser.
- // Each recognized tag is passed to handler which is capable
- // of handling it. Each tag is handled in 3 steps:
- // 1. Handler will modifies state of parser
- // (using its public methods)
- // 2. Parser parses source between starting and ending tag
- // 3. Handler restores original state of the parser
- class wx28HtmlTagHandler : public wxObject
- {
- DECLARE_ABSTRACT_CLASS(wx28HtmlTagHandler)
- public:
- wx28HtmlTagHandler() : wxObject () { m_Parser = NULL; }
- // Sets the parser.
- // NOTE : each _instance_ of handler is guaranteed to be called
- // only by one parser. This means you don't have to care about
- // reentrancy.
- virtual void SetParser(wx28HtmlParser *parser)
- { m_Parser = parser; }
- // Returns list of supported tags. The list is in uppercase and
- // tags are delimited by ','.
- // Example : "I,B,FONT,P"
- // is capable of handling italic, bold, font and paragraph tags
- virtual wxString GetSupportedTags() = 0;
- // This is hadling core method. It does all the Steps 1-3.
- // To process step 2, you can call ParseInner()
- // returned value : true if it called ParseInner(),
- // false etherwise
- virtual bool HandleTag(const wx28HtmlTag& tag) = 0;
- protected:
- // parses input between beginning and ending tag.
- // m_Parser must be set.
- void ParseInner(const wx28HtmlTag& tag)
- { m_Parser->DoParsing(tag.GetBeginPos(), tag.GetEndPos1()); }
- // Parses given source as if it was tag's inner code (see
- // wx28HtmlParser::GetInnerSource). Unlike ParseInner(), this method lets
- // you specify the source code to parse. This is useful when you need to
- // modify the inner text before parsing.
- void ParseInnerSource(const wxString& source);
- wx28HtmlParser *m_Parser;
- DECLARE_NO_COPY_CLASS(wx28HtmlTagHandler)
- };
- // This class is used to parse HTML entities in strings. It can handle
- // both named entities and &#xxxx entries where xxxx is Unicode code.
- class wx28HtmlEntitiesParser : public wxObject
- {
- DECLARE_DYNAMIC_CLASS(wx28HtmlEntitiesParser)
- public:
- wx28HtmlEntitiesParser();
- virtual ~wx28HtmlEntitiesParser();
- // Sets encoding of output string.
- // Has no effect if wxUSE_UNICODE==1
- void SetEncoding(wxFontEncoding encoding);
- // Parses entities in input and replaces them with respective characters
- // (with respect to output encoding)
- wxString Parse(const wxString& input);
- // Returns character for given entity or 0 if the enity is unknown
- wxChar GetEntityChar(const wxString& entity);
- // Returns character that represents given Unicode code
- #if wxUSE_UNICODE
- wxChar GetCharForCode(unsigned code) { return (wxChar)code; }
- #else
- wxChar GetCharForCode(unsigned code);
- #endif
- protected:
- #if !wxUSE_UNICODE
- wxMBConv *m_conv;
- wxFontEncoding m_encoding;
- #endif
- DECLARE_NO_COPY_CLASS(wx28HtmlEntitiesParser)
- };
- #endif // _WX_HTMLPARS_H_
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