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, wxHtmlHelpController is used if wxHTML is
  23 compiled into wxWidgets; otherwise wxExtHelpController is used (for invoking an external
  24 browser).
  25 \end{itemize}
  26
  27 The remaining help controller classes 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 have htmlhelp.h header from Microsoft's HTML Help kit (you don't need
  36 VC++ specific htmlhelp.lib because wxWidgets loads necessary DLL at runtime and so it
  37 works with all compilers).
  38 \item wxBestHelpController, for controlling MS HTML Help or, if Microsoft's runtime is
  39 not available, \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}. You need to provide
  40 {\bf both} CHM and HTB versions of the help file. For 32bit Windows only.
  41 \item wxExtHelpController, for controlling external browsers under Unix.
  42 The default browser is Netscape Navigator. The 'help' sample shows its use.
  43 \item wxWinceHelpController, for controlling a simple {\tt .htm} help controller for Windows CE applications.
  44 \item \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, a sophisticated help controller using \helpref{wxHTML}{wxhtml}, in
  45 a similar style to the Microsoft HTML Help viewer and using some of the same files.
  46 Although it has an API compatible with other help controllers, it has more advanced features, so it is
  47 recommended that you use the specific API for this class instead. Note that if you
  48 use .zip or .htb formats for your books, you
  49 must add this line to your application initialization: {\tt wxFileSystem::AddHandler(new wxZipFSHandler);}
  50 or nothing will be shown in your help window.
  51 \end{itemize}
  52
  53 \wxheading{Derived from}
  54
  55 wxHelpControllerBase\\
  56 \helpref{wxObject}{wxobject}
  57
  58 \wxheading{Include files}
  59
  60 <wx/help.h> (wxWidgets chooses the appropriate help controller class)\\
  61 <wx/helpbase.h> (wxHelpControllerBase class)\\
  62 <wx/helpwin.h> (Windows Help controller)\\
  63 <wx/msw/helpchm.h> (MS HTML Help controller)\\
  64 <wx/generic/helpext.h> (external HTML browser controller)\\
  65 <wx/html/helpctrl.h> (wxHTML based help controller: wxHtmlHelpController)
  66
  67 \wxheading{See also}
  68
  69 \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, \helpref{wxHTML}{wxhtml}
  70
  71 \latexignore{\rtfignore{\wxheading{Members}}}
  72
  73 \membersection{wxHelpController::wxHelpController}\label{wxhelpcontrollerctor}
  74
  75 \func{}{wxHelpController}{\void}
  76
  77 Constructs a help instance object, but does not invoke the help viewer.
  78
  79 \membersection{wxHelpController::\destruct{wxHelpController}}\label{wxhelpcontrollerdtor}
  80
  81 \func{}{\destruct{wxHelpController}}{\void}
  82
  83 Destroys the help instance, closing down the viewer if it is running.
  84
  85 \membersection{wxHelpController::Initialize}\label{wxhelpcontrollerinitialize}
  86
  87 \func{virtual void}{Initialize}{\param{const wxString\& }{file}}
  88
  89 \func{virtual void}{Initialize}{\param{const wxString\& }{file}, \param{int}{ server}}
  90
  91 Initializes the help instance with a help filename, and optionally a server socket
  92 number if using wxHelp (now obsolete). Does not invoke the help viewer.
  93 This must be called directly after the help instance object is created and before
  94 any attempts to communicate with the viewer.
  95
  96 You may omit the file extension and a suitable one will be chosen. For
  97 wxHtmlHelpController, the extensions zip, htb and hhp will be appended while searching for
  98 a suitable file. For WinHelp, the hlp extension is appended.
  99
 100 \membersection{wxHelpController::DisplayBlock}\label{wxhelpcontrollerdisplayblock}
 101
 102 \func{virtual bool}{DisplayBlock}{\param{long}{ blockNo}}
 103
 104 If the help viewer is not running, runs it and displays the file at the given block number.
 105
 106 {\it WinHelp:} Refers to the context number.
 107
 108 {\it MS HTML Help:} Refers to the context number.
 109
 110 {\it External HTML help:} the same as for \helpref{wxHelpController::DisplaySection}{wxhelpcontrollerdisplaysection}.
 111
 112 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 113
 114 This function is for backward compatibility only, and applications should use \helpref{wxHelpController}{wxhelpcontrollerdisplaysection} instead.
 115
 116 \membersection{wxHelpController::DisplayContents}\label{wxhelpcontrollerdisplaycontents}
 117
 118 \func{virtual bool}{DisplayContents}{\void}
 119
 120 If the help viewer is not running, runs it and displays the
 121 contents.
 122
 123 \membersection{wxHelpController::DisplayContextPopup}\label{wxhelpcontrollerdisplaycontextpopup}
 124
 125 \func{virtual bool}{DisplayContextPopup}{\param{int }{contextId}}
 126
 127 Displays the section as a popup window using a context id.
 128
 129 Returns false if unsuccessful or not implemented.
 130
 131 \membersection{wxHelpController::DisplaySection}\label{wxhelpcontrollerdisplaysection}
 132
 133 \func{virtual bool}{DisplaySection}{\param{const wxString\&}{ section}}
 134
 135 If the help viewer is not running, runs it and displays the given section.
 136
 137 The interpretation of {\it section} differs between help viewers. For most viewers,
 138 this call is equivalent to KeywordSearch. For MS HTML Help, wxHTML help and external HTML help,
 139 if {\it section} has a .htm
 140 or .html extension, that HTML file will be displayed; otherwise
 141 a keyword search is done.
 142
 143 \func{virtual bool}{DisplaySection}{\param{int}{ sectionNo}}
 144
 145 If the help viewer is not running, runs it and displays the given section.
 146
 147 {\it WinHelp, MS HTML Help} {\it sectionNo} is a context id.
 148
 149 {\it External HTML help:} wxExtHelpController implements {\it sectionNo} as an id in a map file, which is of the form:
 150
 151 \begin{verbatim}
 152 0  wx.html             ; Index
 153 1  wx34.html#classref  ; Class reference
 154 2  wx204.html          ; Function reference
 155 \end{verbatim}
 156
 157 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 158
 159 See also the help sample for notes on how to specify section numbers for various help file formats.
 160
 161 \membersection{wxHelpController::DisplayTextPopup}\label{wxhelpcontrollerdisplaytextpopup}
 162
 163 \func{virtual bool}{DisplayTextPopup}{\param{const wxString\&}{ text}, \param{const wxPoint\& }{pos}}
 164
 165 Displays the text in a popup window, if possible.
 166
 167 Returns false if unsuccessful or not implemented.
 168
 169 \membersection{wxHelpController::GetFrameParameters}\label{wxhelpcontrollergetframeparameters}
 170
 171 \func{virtual wxFrame *}{GetFrameParameters}{\param{const wxSize * }{size = NULL}, \param{const wxPoint * }{pos = NULL},
 172  \param{bool *}{newFrameEachTime = NULL}}
 173
 174 wxHtmlHelpController returns the frame, size and position.
 175
 176 For all other help controllers, this function does nothing
 177 and just returns NULL.
 178
 179 \wxheading{Parameters}
 180
 181 \docparam{viewer}{This defaults to "netscape" for wxExtHelpController.}
 182
 183 \docparam{flags}{This defaults to wxHELP\_NETSCAPE for wxExtHelpController, indicating
 184 that the viewer is a variant of Netscape Navigator.}
 185
 186 \membersection{wxHelpController::KeywordSearch}\label{wxhelpcontrollerkeywordsearch}
 187
 188 \func{virtual bool}{KeywordSearch}{\param{const wxString\& }{keyWord}, \param{wxHelpSearchMode }{mode = wxHELP\_SEARCH\_ALL}}
 189
 190 If the help viewer is not running, runs it, and searches for sections matching
 191 the given keyword. If one match is found, the file is displayed at this
 192 section. The optional parameter allows the search the index
 193 (wxHELP\_SEARCH\_INDEX) but this currently only supported by the
 194 wxHtmlHelpController.
 195
 196 {\it WinHelp, MS HTML Help:} If more than one match is found,
 197 the first topic is displayed.
 198
 199 {\it External HTML help, simple wxHTML help:} If more than one match is found,
 200 a choice of topics is displayed.
 201
 202 {\it wxHtmlHelpController:} see \helpref{wxHtmlHelpController::KeywordSearch}{wxhtmlhelpcontrollerkeywordsearch}.
 203
 204 \membersection{wxHelpController::LoadFile}\label{wxhelpcontrollerloadfile}
 205
 206 \func{virtual bool}{LoadFile}{\param{const wxString\& }{file = ""}}
 207
 208 If the help viewer is not running, runs it and loads the given file.
 209 If the filename is not supplied or is
 210 empty, the file specified in {\bf Initialize} is used. If the viewer is
 211 already displaying the specified file, it will not be reloaded. This
 212 member function may be used before each display call in case the user
 213 has opened another file.
 214
 215 wxHtmlHelpController ignores this call.
 216
 217 \membersection{wxHelpController::OnQuit}\label{wxhelpcontrolleronquit}
 218
 219 \func{virtual bool}{OnQuit}{\void}
 220
 221 Overridable member called when this application's viewer is quit by the user.
 222
 223 This does not work for all help controllers.
 224
 225 \membersection{wxHelpController::SetFrameParameters}\label{wxhelpcontrollersetframeparameters}
 226
 227 \func{virtual void}{SetFrameParameters}{\param{const wxString \& }{title},
 228  \param{const wxSize \& }{size}, \param{const wxPoint \& }{pos = wxDefaultPosition},
 229  \param{bool }{newFrameEachTime = false}}
 230
 231 For wxHtmlHelpController, the title is set (again with \%s indicating the
 232 page title) and also the size and position of the frame if the frame is already
 233 open. {\it newFrameEachTime} is ignored.
 234
 235 For all other help controllers this function has no effect.
 236
 237 \membersection{wxHelpController::SetViewer}\label{wxhelpcontrollersetviewer}
 238
 239 \func{virtual void}{SetViewer}{\param{const wxString\& }{viewer}, \param{long}{ flags}}
 240
 241 Sets detailed viewer information. So far this is only relevant to wxExtHelpController.
 242
 243 Some examples of usage:
 244
 245 \begin{verbatim}
 246   m_help.SetViewer("kdehelp");
 247   m_help.SetViewer("gnome-help-browser");
 248   m_help.SetViewer("netscape", wxHELP_NETSCAPE);
 249 \end{verbatim}
 250
 251 \membersection{wxHelpController::Quit}\label{wxhelpcontrollerquit}
 252
 253 \func{virtual bool}{Quit}{\void}
 254
 255 If the viewer is running, quits it by disconnecting.
 256
 257 For Windows Help, the viewer will only close if no other application is using it.
 258