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