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 Although it has an API compatible with other help controllers, it has more advanced features, so it is
  42 recommended that you use the specific API for this class instead.
  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> (simple wxHTML-based help controller)\\
  57 <wx/html/helpctrl.h> (advanced wxHTML based help controller: wxHtmlHelpController)
  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. For
  89 wxHtmlHelpController, the extensions zip, htb and hhp will be appended while searching for
  90 a suitable file. For WinHelp, the hlp extension is appended. For wxHelpControllerHtml (the
  91 standard HTML help controller), the filename is assumed to be a directory containing
  92 the HTML files.
  93
  94 \membersection{wxHelpController::DisplayBlock}\label{wxhelpcontrollerdisplayblock}
  95
  96 \func{virtual bool}{DisplayBlock}{\param{long}{ blockNo}}
  97
  98 If the help viewer is not running, runs it and displays the file at the given block number.
  99
 100 {\it WinHelp:} Refers to the context number.
 101
 102 {\it External HTML help:} the same as for \helpref{wxHelpController::DisplaySection}{wxhelpcontrollerdisplaysection}.
 103
 104 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 105
 106 \membersection{wxHelpController::DisplayContents}\label{wxhelpcontrollerdisplaycontents}
 107
 108 \func{virtual bool}{DisplayContents}{\void}
 109
 110 If the help viewer is not running, runs it and displays the
 111 contents.
 112
 113 \membersection{wxHelpController::DisplaySection}\label{wxhelpcontrollerdisplaysection}
 114
 115 \func{virtual bool}{DisplaySection}{\param{int}{ sectionNo}}
 116
 117 If the help viewer is not running, runs it and displays the given section.
 118
 119 {\it WinHelp:} {\it sectionNo} is a context id.
 120
 121 {\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:
 122
 123 \begin{verbatim}
 124 0  wx.html             ; Index
 125 1  wx34.html#classref  ; Class reference
 126 2  wx204.html          ; Function reference
 127 \end{verbatim}
 128
 129 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 130
 131 \membersection{wxHelpController::GetFrameParameters}\label{wxhelpcontrollergetframeparameters}
 132
 133 \func{virtual wxFrame *}{GetFrameParameters}{\param{const wxSize * }{size = NULL}, \param{const wxPoint * }{pos = NULL},
 134  \param{bool *}{newFrameEachTime = NULL}}
 135
 136 This reads the current settings for the help frame in the case of the
 137 wxHelpControllerHtml, setting the frame size, position and
 138 the newFrameEachTime parameters to the last values used. It also
 139 returns the pointer to the last opened help frame. This can be used
 140 for example, to automatically close the help frame on program
 141 shutdown.
 142
 143 wxHtmlHelpController returns the frame,
 144 size and position.
 145
 146 For all other help controllers, this function does nothing
 147 and just returns NULL.
 148
 149 \wxheading{Parameters}
 150
 151 \docparam{viewer}{This defaults to "netscape" for wxExtHelpController.}
 152
 153 \docparam{flags}{This defaults to wxHELP\_NETSCAPE for wxExtHelpController, indicating
 154 that the viewer is a variant of Netscape Navigator.}
 155
 156 \membersection{wxHelpController::KeywordSearch}\label{wxhelpcontrollerkeywordsearch}
 157
 158 \func{virtual bool}{KeywordSearch}{\param{const wxString\& }{keyWord}}
 159
 160 If the help viewer is not running, runs it, and searches for sections matching the given keyword. If one
 161 match is found, the file is displayed at this section.
 162
 163 {\it WinHelp:} If more than one match is found,
 164 the first topic is displayed.
 165
 166 {\it External HTML help:} If more than one match is found,
 167 a choice of topics is displayed.
 168
 169 {\it wxHtmlHelpController:} see \helpref{wxHtmlHelpController::KeywordSearch}{wxhtmlhelpcontrollerkeywordsearch}.
 170
 171 \membersection{wxHelpController::LoadFile}\label{wxhelpcontrollerloadfile}
 172
 173 \func{virtual bool}{LoadFile}{\param{const wxString\& }{file = ""}}
 174
 175 If the help viewer is not running, runs it and loads the given file.
 176 If the filename is not supplied or is
 177 empty, the file specified in {\bf Initialize} is used. If the viewer is
 178 already displaying the specified file, it will not be reloaded. This
 179 member function may be used before each display call in case the user
 180 has opened another file.
 181
 182 wxHtmlHelpController ignores this call.
 183
 184 \membersection{wxHelpController::OnQuit}\label{wxhelpcontrolleronquit}
 185
 186 \func{virtual bool}{OnQuit}{\void}
 187
 188 Overridable member called when this application's viewer is quit by the user.
 189
 190 This does not work for all help controllers.
 191
 192 \membersection{wxHelpController::SetFrameParameters}\label{wxhelpcontrollersetframeparameters}
 193
 194 \func{virtual void}{SetFrameParameters}{\param{const wxString \& }{title},
 195  \param{const wxSize \& }{size}, \param{const wxPoint \& }{pos = wxDefaultPosition},
 196  \param{bool }{newFrameEachTime = FALSE}}
 197
 198 For wxHelpControllerHtml, this allows the application to set the
 199 default frame title, size and position for the frame. If the title
 200 contains \%s, this will be replaced with the page title. If the
 201 parameter newFrameEachTime is set, the controller will open a new
 202 help frame each time it is called.
 203
 204 For wxHtmlHelpController, the title is set (again with \%s indicating the
 205 page title) and also the size and position of the frame if the frame is already
 206 open. {\it newFrameEachTime} is ignored.
 207
 208 For all other help controllers this function has no effect.
 209
 210 \membersection{wxHelpController::SetViewer}\label{wxhelpcontrollersetviewer}
 211
 212 \func{virtual void}{SetViewer}{\param{const wxString\& }{viewer}, \param{long}{ flags}}
 213
 214 Sets detailed viewer information. So far this is only relevant to wxExtHelpController.
 215
 216 Some examples of usage:
 217
 218 \begin{verbatim}
 219   m_help.SetViewer("kdehelp");
 220   m_help.SetViewer("gnome-help-browser");
 221   m_help.SetViewer("netscape", wxHELP_NETSCAPE);
 222 \end{verbatim}
 223
 224 \membersection{wxHelpController::Quit}\label{wxhelpcontrollerquit}
 225
 226 \func{virtual bool}{Quit}{\void}
 227
 228 If the viewer is running, quits it by disconnecting.
 229
 230 For Windows Help, the viewer will only close if no other application is using it.
 231