docs/latex/wx/filesysh.tex

   1 %
   2 % automatically generated by HelpGen from
   3 % filesystemhandler.tex at 21/Mar/99 23:00:52
   4 %
   5
   6 \section{\class{wxFileSystemHandler}}\label{wxfilesystemhandler}
   7
   8 Classes derived from wxFileSystemHandler are used
   9 to access virtual file systems. Its public interface consists
  10 of two methods: \helpref{CanOpen}{wxfilesystemhandlercanopen}
  11 and \helpref{OpenFile}{wxfilesystemhandleropenfile}.
  12 It provides additional protected methods to simplify the process
  13 of opening the file: GetProtocol, GetLeftLocation, GetRightLocation,
  14 GetAnchor, GetMimeTypeFromExt.
  15
  16 Please have a look at \helpref{overview}{fs} if you don't know how locations
  17 are constructed.
  18
  19 \wxheading{Notes}
  20
  21 \begin{itemize}\itemsep=0pt
  22 \item The handlers are shared by all instances of wxFileSystem.
  23 \item wxHTML library provides handlers for local files and HTTP or FTP protocol
  24 \item The {\it location} parameter passed to OpenFile or CanOpen methods
  25 is always an {\bf absolute} path. You don't need to check the FS's current path.
  26 \end{itemize}
  27
  28 \wxheading{Derived from}
  29
  30 wxObject
  31
  32 \wxheading{See also}
  33
  34 \helpref{wxFileSystem}{wxfilesystem},
  35 \helpref{wxFSFile}{wxfsfile},
  36 \helpref{Overview}{fs}
  37
  38 \membersection{wxFileSystemHandler::wxFileSystemHandler}\label{wxfilesystemhandlerwxfilesystemhandler}
  39
  40 \func{}{wxFileSystemHandler}{\void}
  41
  42 Constructor.
  43
  44 \membersection{wxFileSystemHandler::CanOpen}\label{wxfilesystemhandlercanopen}
  45
  46 \func{virtual bool}{CanOpen}{\param{const wxString\& }{location}}
  47
  48 Returns TRUE if the handler is able to open this file. This function doesn't
  49 check whether the file exists or not, it only checks if it knows the protocol.
  50 Example:
  51
  52 \begin{verbatim}
  53 bool MyHand::CanOpen(const wxString& location)
  54 {
  55     return (GetProtocol(location) == "http");
  56 }
  57 \end{verbatim}
  58
  59 Must be overridden in derived handlers.
  60
  61 \membersection{wxFileSystemHandler::GetAnchor}\label{wxfilesystemhandlergetanchor}
  62
  63 \constfunc{wxString}{GetAnchor}{\param{const wxString\& }{location}}
  64
  65 Returns the anchor if present in the location.
  66 See \helpref{wxFSFile}{wxfsfilegetanchor} for details.
  67
  68 Example: GetAnchor("index.htm\#chapter2") == "chapter2"
  69
  70 {\bf Note:} the anchor is NOT part of the left location.
  71
  72 \membersection{wxFileSystemHandler::GetLeftLocation}\label{wxfilesystemhandlergetleftlocation}
  73
  74 \constfunc{wxString}{GetLeftLocation}{\param{const wxString\& }{location}}
  75
  76 Returns the left location string extracted from {\it location}.
  77
  78 Example: GetLeftLocation("file:myzipfile.zip\#zip:index.htm") == "file:myzipfile.zip"
  79
  80 \membersection{wxFileSystemHandler::GetMimeTypeFromExt}\label{wxfilesystemhandlergetmimetypefromext}
  81
  82 \func{wxString}{GetMimeTypeFromExt}{\param{const wxString\& }{location}}
  83
  84 Returns the MIME type based on {\bf extension} of {\it location}. (While wxFSFile::GetMimeType
  85 returns real MIME type - either extension-based or queried from HTTP.)
  86
  87 Example : GetMimeTypeFromExt("index.htm") == "text/html"
  88
  89 \membersection{wxFileSystemHandler::GetProtocol}\label{wxfilesystemhandlergetprotocol}
  90
  91 \constfunc{wxString}{GetProtocol}{\param{const wxString\& }{location}}
  92
  93 Returns the protocol string extracted from {\it location}.
  94
  95 Example: GetProtocol("file:myzipfile.zip\#zip:index.htm") == "zip"
  96
  97 \membersection{wxFileSystemHandler::GetRightLocation}\label{wxfilesystemhandlergetrightlocation}
  98
  99 \constfunc{wxString}{GetRightLocation}{\param{const wxString\& }{location}}
 100
 101 Returns the right location string extracted from {\it location}.
 102
 103 Example : GetRightLocation("file:myzipfile.zip\#zip:index.htm") == "index.htm"
 104
 105 \membersection{wxFileSystemHandler::FindFirst}\label{wxfilesystemhandlerfindfirst}
 106
 107 \func{virtual wxString}{FindFirst}{\param{const wxString\& }{wildcard}, \param{int }{flags = 0}}
 108
 109 Works like \helpref{wxFindFirstFile}{wxfindfirstfile}. Returns name of the first
 110 filename (withing filesystem's current path) that matches {\it wildcard}. {\it flags} may be one of
 111 wxFILE (only files), wxDIR (only directories) or 0 (both).
 112
 113 This method is only called if \helpref{CanOpen}{wxfilesystemhandlercanopen} returns TRUE.
 114
 115 \membersection{wxFileSystemHandler::FindNext}\label{wxfilesystemhandlerfindnext}
 116
 117 \func{virtual wxString}{FindNext}{\void}
 118
 119 Returns next filename that matches parameters passed to \helpref{FindFirst}{wxfilesystemfindfirst}.
 120
 121 This method is only called if \helpref{CanRead}{wxfilesystemhandlercanread} returns TRUE and FindFirst
 122 returned a non-empty string.
 123
 124 \membersection{wxFileSystemHandler::OpenFile}\label{wxfilesystemhandleropenfile}
 125
 126 \func{virtual wxFSFile*}{OpenFile}{\param{wxFileSystem\& }{fs}, \param{const wxString\& }{location}}
 127
 128 Opens the file and returns wxFSFile pointer or NULL if failed.
 129
 130 Must be overridden in derived handlers.
 131
 132 \wxheading{Parameters}
 133
 134 \docparam{fs}{Parent FS (the FS from that OpenFile was called). See ZIP handler
 135 for details of how to use it.}
 136
 137 \docparam{location}{The {\bf absolute} location of file.}
 138