docs/latex/wx/helpinst.tex

   1 \section{\class{wxHelpController}}\label{wxhelpcontroller}
   2
   3 This is a family of classes by which
   4 applications may invoke a help viewer to provide on-line help.
   5
   6 A help controller allows an application to display help, at the contents
   7 or at a particular topic, and shut the help program down on termination.
   8 This avoids proliferation of many instances of the help viewer whenever the
   9 user requests a different topic via the application's menus or buttons.
  10
  11 Typically, an application will create a help controller instance
  12 when it starts, and immediately call {\bf Initialize}\rtfsp
  13 to associate a filename with it. The help viewer will only get run, however,
  14 just before the first call to display something.
  15
  16 Most help controller classes actually derive from wxHelpControllerBase and have
  17 names of the form wxXXXHelpController or wxHelpControllerXXX. An
  18 appropriate class is aliased to the name wxHelpController for each platform, as follows:
  19
  20 \begin{itemize}\itemsep=0pt
  21 \item On Windows, wxWinHelpController is used.
  22 \item On all other platforms, wxHelpControllerHtml is used if wxHTML is
  23 compiled into wxWindows; otherwise wxExtHelpController is used (for invoking an external
  24 browser).
  25 \end{itemize}
  26
  27 The remaining help controller classess need to be named
  28 explicitly by an application that wishes to make use of them.
  29
  30 There are currently the following help controller classes defined:
  31
  32 \begin{itemize}\itemsep=0pt
  33 \item wxWinHelpController, for controlling Windows Help.
  34 \item wxExtHelpController, for controlling external browsers under Unix.
  35 The default browser is Netscape Navigator. The 'help' sample shows its use.
  36 \item wxHelpControllerHtml, using \helpref{wxHTML}{wxhtml} to display help. The API for this class
  37 is reasonably close to the wxWindows help controller API; see {\tt wx/helpwxht.h} for
  38 details of use.
  39 \item \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, a more sophisticated help controller using \helpref{wxHTML}{wxhtml}, in
  40 a similar style to the Windows HTML Help viewer and using some of the same files.
  41 The API is not the same as the standard API, which is why it is documented separately.
  42 \item wxXLPHelpController, for controlling wxHelp (from wxWindows 1). Obsolete.
  43 \end{itemize}
  44
  45 \wxheading{Derived from}
  46
  47 wxHelpControllerBase\\
  48 \helpref{wxObject}{wxobject}
  49
  50 \wxheading{Include files}
  51
  52 <wx/help.h> (wxWindows chooses the appropriate help controller class)\\
  53 <wx/helpbase.h> (wxHelpControllerBase class)\\
  54 <wx/helpwin.h> (Windows Help controller)\\
  55 <wx/generic/helpext.h> (external HTML browser controller)
  56 <wx/generic/helpwxht.h> (wxHTML based help controller)
  57 <wx/generic/helpxlp.h> (wxHelp controller)
  58
  59 \wxheading{See also}
  60
  61 \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, \helpref{wxHTML}{wxhtml}
  62
  63 \latexignore{\rtfignore{\wxheading{Members}}}
  64
  65 \membersection{wxHelpController::wxHelpController}
  66
  67 \func{}{wxHelpController}{\void}
  68
  69 Constructs a help instance object, but does not invoke the help viewer.
  70
  71 \membersection{wxHelpController::\destruct{wxHelpController}}
  72
  73 \func{}{\destruct{wxHelpController}}{\void}
  74
  75 Destroys the help instance, closing down the viewer if it is running.
  76
  77 \membersection{wxHelpController::Initialize}\label{wxhelpcontrollerinitialize}
  78
  79 \func{virtual void}{Initialize}{\param{const wxString\& }{file}}
  80
  81 \func{virtual void}{Initialize}{\param{const wxString\& }{file}, \param{int}{ server}}
  82
  83 Initializes the help instance with a help filename, and optionally a server (socket)
  84 number if using wxHelp. Does not invoke the help viewer.
  85 This must be called directly after the help instance object is created and before
  86 any attempts to communicate with the viewer.
  87
  88 You may omit the file extension and a suitable one will be chosen.
  89
  90 \membersection{wxHelpController::DisplayBlock}\label{wxhelpcontrollerdisplayblock}
  91
  92 \func{virtual bool}{DisplayBlock}{\param{long}{ blockNo}}
  93
  94 If the help viewer is not running, runs it and displays the file at the given block number.
  95
  96 {\it wxHelp:} this is the wxHelp block number.
  97
  98 {\it WinHelp:} Refers to the context number.
  99
 100 {\it External HTML help:} the same as for \helpref{wxHelpController::DisplaySection}{wxhelpcontrollerdisplaysection}.
 101
 102 \membersection{wxHelpController::DisplayContents}\label{wxhelpcontrollerdisplaycontents}
 103
 104 \func{virtual bool}{DisplayContents}{\void}
 105
 106 If the help viewer is not running, runs it and displays the
 107 contents.
 108
 109 \membersection{wxHelpController::DisplaySection}\label{wxhelpcontrollerdisplaysection}
 110
 111 \func{virtual bool}{DisplaySection}{\param{int}{ sectionNo}}
 112
 113 If the help viewer is not running, runs it and displays the given section.
 114
 115 {\it wxHelp:} Sections are numbered starting from 1. Section numbers may be viewed by running wxHelp in edit mode.
 116
 117 {\it WinHelp:} {\it sectionNo} is a context id.
 118
 119 {\it External HTML help/wxHTML based help:} wxExtHelpController and wxHelpControllerHtml implement {\it sectionNo} as an id in a map file, which is of the form:
 120
 121 \begin{verbatim}
 122 0  wx.html             ; Index
 123 1  wx34.html#classref  ; Class reference
 124 2  wx204.html          ; Function reference
 125 \end{verbatim}
 126
 127 \membersection{wxHelpController::KeywordSearch}\label{wxhelpcontrollerkeywordsearch}
 128
 129 \func{virtual bool}{KeywordSearch}{\param{const wxString\& }{keyWord}}
 130
 131 If the help viewer is not running, runs it, and searches for sections matching the given keyword. If one
 132 match is found, the file is displayed at this section.
 133
 134 {\it wxHelp:} If more than one
 135 match is found, the Search dialog is displayed with the matches.
 136
 137 {\it WinHelp:} If more than one match is found,
 138 the first topic is displayed.
 139
 140 {\it External HTML help:} If more than one match is found,
 141 a choice of topics is displayed.
 142
 143 \membersection{wxHelpController::LoadFile}\label{wxhelpcontrollerloadfile}
 144
 145 \func{virtual bool}{LoadFile}{\param{const wxString\& }{file = ""}}
 146
 147 If the help viewer is not running, runs it and loads the given file.
 148 If the filename is not supplied or is
 149 NULL, the file specified in {\bf Initialize} is used. If the viewer is
 150 already displaying the specified file, it will not be reloaded. This
 151 member function may be used before each display call in case the user
 152 has opened another file.
 153
 154 \membersection{wxHelpController::SetViewer}\label{wxhelpcontrollersetviewer}
 155
 156 \func{virtual void}{SetViewer}{\param{const wxString\& }{viewer}, \param{long}{ flags}}
 157
 158 Sets detailed viewer information. So far this is only relevant to wxExtHelpController.
 159
 160 \membersection{wxHelpController::SetFrameParameters}\label{wxhelpcontrollersetframeparameters}
 161 \func{virtual void}{SetFrameParameters}
 162 {\param{const wxString \& }{title},
 163  \param{const wxSize \& }{size}, \param{const wxPoint \& }{pos = wxDefaultPosition},
 164  \param{bool }{newFrameEachTime = FALSE}}
 165
 166 For the wxHelpControllerHtml, this allows the application to set the
 167 default frame title, size and position for the frame. If the title
 168 contains \%s, this will be replaced with the page title. If the
 169 parammeter newFrameEachTime is set, the controller will open a new
 170 help frame each time it is called. For all other help controllers this
 171 function has no effect.
 172
 173 \membersection{wxHelpController::GetFrameParameters}\label{wxhelpcontrollergetframeparameters}
 174 \func{virtual wxFrame *}{GetFrameParameters}
 175 {\param{const wxSize * }{size = NULL}, \param{const wxPoint * }{pos = NULL},
 176  \param{bool *}{newFrameEachTime = NULL}}
 177 This reads the current settings for the help frame in the case of the
 178 wxHelpControllerHtml, setting the frame size, position and
 179 the newFrameEachTime parameters to the last values used. It also
 180 returns the pointer to the last opened help frame. This can be used
 181 for example, to automatically close the help frame on program
 182 shutdown. For all other help controllers, this function does nothing
 183 and just returns NULL.
 184
 185 \wxheading{Parameters}
 186
 187 \docparam{viewer}{This defaults to "netscape" for wxExtHelpController.}
 188
 189 \docparam{flags}{This defaults to wxHELP\_NETSCAPE for wxExtHelpController, indicating
 190 that the viewer is a variant of Netscape Navigator.}
 191
 192 \membersection{wxHelpController::OnQuit}\label{wxhelpcontrolleronquit}
 193
 194 \func{virtual bool}{OnQuit}{\void}
 195
 196 Overridable member called when this application's viewer is quit by the user.
 197
 198 This does not work for all help controllers.
 199
 200 \membersection{wxHelpController::Quit}\label{wxhelpcontrollerquit}
 201
 202 \func{virtual bool}{Quit}{\void}
 203
 204 If the viewer is running, quits it by disconnecting.
 205
 206 For Windows Help, the viewer will only close if no other application is using it.
 207