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 wxCHMHelpController, for controlling MS HTML Help. To use this, you need to set wxUSE\_MS\_HTML\_HELP
  35 to 1 in setup.h, and link your application with Microsoft's htmlhelp.lib. Currently VC++ only.
  36 \item wxExtHelpController, for controlling external browsers under Unix.
  37 The default browser is Netscape Navigator. The 'help' sample shows its use.
  38 \item wxHelpControllerHtml, using \helpref{wxHTML}{wxhtml} to display help. See {\tt wx/helpwxht.h} for
  39 details of use.
  40 \item \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, a more sophisticated help controller using \helpref{wxHTML}{wxhtml}, in
  41 a similar style to the Microsoft HTML Help viewer and using some of the same files.
  42 Although it has an API compatible with other help controllers, it has more advanced features, so it is
  43 recommended that you use the specific API for this class instead.
  44 \end{itemize}
  45
  46 \wxheading{Derived from}
  47
  48 wxHelpControllerBase\\
  49 \helpref{wxObject}{wxobject}
  50
  51 \wxheading{Include files}
  52
  53 <wx/help.h> (wxWindows chooses the appropriate help controller class)\\
  54 <wx/helpbase.h> (wxHelpControllerBase class)\\
  55 <wx/helpwin.h> (Windows Help controller)\\
  56 <wx/msw/helpchm.h> (MS HTML Help controller)\\
  57 <wx/generic/helpext.h> (external HTML browser controller)\\
  58 <wx/generic/helpwxht.h> (simple wxHTML-based help controller)\\
  59 <wx/html/helpctrl.h> (advanced wxHTML based help controller: wxHtmlHelpController)
  60
  61 \wxheading{See also}
  62
  63 \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, \helpref{wxHTML}{wxhtml}
  64
  65 \latexignore{\rtfignore{\wxheading{Members}}}
  66
  67 \membersection{wxHelpController::wxHelpController}
  68
  69 \func{}{wxHelpController}{\void}
  70
  71 Constructs a help instance object, but does not invoke the help viewer.
  72
  73 \membersection{wxHelpController::\destruct{wxHelpController}}
  74
  75 \func{}{\destruct{wxHelpController}}{\void}
  76
  77 Destroys the help instance, closing down the viewer if it is running.
  78
  79 \membersection{wxHelpController::Initialize}\label{wxhelpcontrollerinitialize}
  80
  81 \func{virtual void}{Initialize}{\param{const wxString\& }{file}}
  82
  83 \func{virtual void}{Initialize}{\param{const wxString\& }{file}, \param{int}{ server}}
  84
  85 Initializes the help instance with a help filename, and optionally a server socket
  86 number if using wxHelp (now obsolete). Does not invoke the help viewer.
  87 This must be called directly after the help instance object is created and before
  88 any attempts to communicate with the viewer.
  89
  90 You may omit the file extension and a suitable one will be chosen. For
  91 wxHtmlHelpController, the extensions zip, htb and hhp will be appended while searching for
  92 a suitable file. For WinHelp, the hlp extension is appended. For wxHelpControllerHtml (the
  93 standard HTML help controller), the filename is assumed to be a directory containing
  94 the HTML files.
  95
  96 \membersection{wxHelpController::DisplayBlock}\label{wxhelpcontrollerdisplayblock}
  97
  98 \func{virtual bool}{DisplayBlock}{\param{long}{ blockNo}}
  99
 100 If the help viewer is not running, runs it and displays the file at the given block number.
 101
 102 {\it WinHelp:} Refers to the context number.
 103
 104 {\it MS HTML Help:} Refers to the context number.
 105
 106 {\it External HTML help:} the same as for \helpref{wxHelpController::DisplaySection}{wxhelpcontrollerdisplaysection}.
 107
 108 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 109
 110 This function is for backward compatibility only, and applications should use \helpref{wxHelpController}{wxhelpcontrollerdisplaysection} instead.
 111
 112 \membersection{wxHelpController::DisplayContents}\label{wxhelpcontrollerdisplaycontents}
 113
 114 \func{virtual bool}{DisplayContents}{\void}
 115
 116 If the help viewer is not running, runs it and displays the
 117 contents.
 118
 119 \membersection{wxHelpController::DisplayContextPopup}\label{wxhelpcontrollerdisplaycontextpopup}
 120
 121 \func{virtual bool}{DisplayContextPopup}{\param{int }{contextId}}
 122
 123 Displays the section as a popup window using a context id.
 124
 125 Returns FALSE if unsuccessful or not implemented.
 126
 127 \membersection{wxHelpController::DisplaySection}\label{wxhelpcontrollerdisplaysection}
 128
 129 \func{virtual bool}{DisplaySection}{\param{const wxString\&}{ section}}
 130
 131 If the help viewer is not running, runs it and displays the given section.
 132
 133 The interpretation of {\it section} differs between help viewers. For most viewers,
 134 this call is equivalent to KeywordSearch. For MS HTML Help, external HTML help
 135 and simple wxHTML help, if {\it section} has a .htm
 136 or .html extension, that HTML file will be displayed; otherwise
 137 a keyword search is done.
 138
 139 \func{virtual bool}{DisplaySection}{\param{int}{ sectionNo}}
 140
 141 If the help viewer is not running, runs it and displays the given section.
 142
 143 {\it WinHelp, MS HTML Help:} {\it sectionNo} is a context id.
 144
 145 {\it External HTML help/simple wxHTML help:} wxExtHelpController and wxHelpControllerHtml implement {\it sectionNo} as an id in a map file, which is of the form:
 146
 147 \begin{verbatim}
 148 0  wx.html             ; Index
 149 1  wx34.html#classref  ; Class reference
 150 2  wx204.html          ; Function reference
 151 \end{verbatim}
 152
 153 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 154
 155 See also the help sample for notes on how to specify section numbers for various help file formats.
 156
 157 \membersection{wxHelpController::DisplayTextPopup}\label{wxhelpcontrollerdisplaytextpopup}
 158
 159 \func{virtual bool}{DisplayTextPopup}{\param{const wxString\&}{ text}, \param{const wxPoint\& }{pos}}
 160
 161 Displays the text in a popup window, if possible.
 162
 163 Returns FALSE if unsuccessful or not implemented.
 164
 165 \membersection{wxHelpController::GetFrameParameters}\label{wxhelpcontrollergetframeparameters}
 166
 167 \func{virtual wxFrame *}{GetFrameParameters}{\param{const wxSize * }{size = NULL}, \param{const wxPoint * }{pos = NULL},
 168  \param{bool *}{newFrameEachTime = NULL}}
 169
 170 This reads the current settings for the help frame in the case of the
 171 wxHelpControllerHtml, setting the frame size, position and
 172 the newFrameEachTime parameters to the last values used. It also
 173 returns the pointer to the last opened help frame. This can be used
 174 for example, to automatically close the help frame on program
 175 shutdown.
 176
 177 wxHtmlHelpController returns the frame,
 178 size and position.
 179
 180 For all other help controllers, this function does nothing
 181 and just returns NULL.
 182
 183 \wxheading{Parameters}
 184
 185 \docparam{viewer}{This defaults to "netscape" for wxExtHelpController.}
 186
 187 \docparam{flags}{This defaults to wxHELP\_NETSCAPE for wxExtHelpController, indicating
 188 that the viewer is a variant of Netscape Navigator.}
 189
 190 \membersection{wxHelpController::KeywordSearch}\label{wxhelpcontrollerkeywordsearch}
 191
 192 \func{virtual bool}{KeywordSearch}{\param{const wxString\& }{keyWord}}
 193
 194 If the help viewer is not running, runs it, and searches for sections matching the given keyword. If one
 195 match is found, the file is displayed at this section.
 196
 197 {\it WinHelp, MS HTML Help:} If more than one match is found,
 198 the first topic is displayed.
 199
 200 {\it External HTML help, simple wxHTML help:} If more than one match is found,
 201 a choice of topics is displayed.
 202
 203 {\it wxHtmlHelpController:} see \helpref{wxHtmlHelpController::KeywordSearch}{wxhtmlhelpcontrollerkeywordsearch}.
 204
 205 \membersection{wxHelpController::LoadFile}\label{wxhelpcontrollerloadfile}
 206
 207 \func{virtual bool}{LoadFile}{\param{const wxString\& }{file = ""}}
 208
 209 If the help viewer is not running, runs it and loads the given file.
 210 If the filename is not supplied or is
 211 empty, the file specified in {\bf Initialize} is used. If the viewer is
 212 already displaying the specified file, it will not be reloaded. This
 213 member function may be used before each display call in case the user
 214 has opened another file.
 215
 216 wxHtmlHelpController ignores this call.
 217
 218 \membersection{wxHelpController::OnQuit}\label{wxhelpcontrolleronquit}
 219
 220 \func{virtual bool}{OnQuit}{\void}
 221
 222 Overridable member called when this application's viewer is quit by the user.
 223
 224 This does not work for all help controllers.
 225
 226 \membersection{wxHelpController::SetFrameParameters}\label{wxhelpcontrollersetframeparameters}
 227
 228 \func{virtual void}{SetFrameParameters}{\param{const wxString \& }{title},
 229  \param{const wxSize \& }{size}, \param{const wxPoint \& }{pos = wxDefaultPosition},
 230  \param{bool }{newFrameEachTime = FALSE}}
 231
 232 For wxHelpControllerHtml, this allows the application to set the
 233 default frame title, size and position for the frame. If the title
 234 contains \%s, this will be replaced with the page title. If the
 235 parameter newFrameEachTime is set, the controller will open a new
 236 help frame each time it is called.
 237
 238 For wxHtmlHelpController, the title is set (again with \%s indicating the
 239 page title) and also the size and position of the frame if the frame is already
 240 open. {\it newFrameEachTime} is ignored.
 241
 242 For all other help controllers this function has no effect.
 243
 244 \membersection{wxHelpController::SetViewer}\label{wxhelpcontrollersetviewer}
 245
 246 \func{virtual void}{SetViewer}{\param{const wxString\& }{viewer}, \param{long}{ flags}}
 247
 248 Sets detailed viewer information. So far this is only relevant to wxExtHelpController.
 249
 250 Some examples of usage:
 251
 252 \begin{verbatim}
 253   m_help.SetViewer("kdehelp");
 254   m_help.SetViewer("gnome-help-browser");
 255   m_help.SetViewer("netscape", wxHELP_NETSCAPE);
 256 \end{verbatim}
 257
 258 \membersection{wxHelpController::Quit}\label{wxhelpcontrollerquit}
 259
 260 \func{virtual bool}{Quit}{\void}
 261
 262 If the viewer is running, quits it by disconnecting.
 263
 264 For Windows Help, the viewer will only close if no other application is using it.
 265