docs/latex/wx/module.tex

   1 \section{\class{wxModule}}\label{wxmodule}
   2
   3 The module system is a very simple mechanism to allow applications (and parts
   4 of wxWidgets itself) to define initialization and cleanup functions that are
   5 automatically called on wxWidgets startup and exit.
   6
   7 To define a new kind of module, derive a class from wxModule, override the
   8 \helpref{OnInit}{wxmoduleoninit} and \helpref{OnExit}{wxmoduleonexit}
   9 functions, and add the DECLARE\_DYNAMIC\_CLASS and IMPLEMENT\_DYNAMIC\_CLASS to
  10 header and implementation files (which can be the same file). On
  11 initialization, wxWidgets will find all classes derived from wxModule, create
  12 an instance of each, and call each OnInit function. On exit, wxWidgets will
  13 call the OnExit function for each module instance.
  14
  15 Note that your module class does not have to be in a header file.
  16
  17 For example:
  18
  19 \begin{verbatim}
  20   // A module to allow DDE initialization/cleanup
  21   // without calling these functions from app.cpp or from
  22   // the user's application.
  23   class wxDDEModule: public wxModule
  24   {
  25   public:
  26       wxDDEModule() { }
  27       virtual bool OnInit() { wxDDEInitialize(); return true; };
  28       virtual void OnExit() { wxDDECleanUp(); };
  29
  30   private:
  31       DECLARE_DYNAMIC_CLASS(wxDDEModule)
  32   };
  33
  34   IMPLEMENT_DYNAMIC_CLASS(wxDDEModule, wxModule)
  35
  36
  37   // Another module which uses DDE in its OnInit()
  38   class MyModule: public wxModule
  39   {
  40   public:
  41       MyModule() { AddDependency(CLASSINFO(wxDDEModule)); }
  42       virtual bool OnInit() { ... code using DDE ... }
  43       virtual void OnExit() { ... }
  44
  45   private:
  46       DECLARE_DYNAMIC_CLASS(MyModule)
  47   };
  48
  49   IMPLEMENT_DYNAMIC_CLASS(MyModule, wxModule)
  50
  51   // Another module which uses DDE in its OnInit()
  52   // but uses a named dependency
  53   class MyModule2: public wxModule
  54   {
  55   public:
  56       MyModule2() { AddDependency("wxDDEModule"); }
  57       virtual bool OnInit() { ... code using DDE ... }
  58       virtual void OnExit() { ... }
  59
  60   private:
  61       DECLARE_DYNAMIC_CLASS(MyModule2)
  62   };
  63
  64   IMPLEMENT_DYNAMIC_CLASS(MyModule2, wxModule)
  65 \end{verbatim}
  66
  67 \wxheading{Derived from}
  68
  69 \helpref{wxObject}{wxobject}
  70
  71 \wxheading{Include files}
  72
  73 <wx/module.h>
  74
  75 \wxheading{Library}
  76
  77 \helpref{wxBase}{librarieslist}
  78
  79 \latexignore{\rtfignore{\wxheading{Members}}}
  80
  81
  82 \membersection{wxModule::wxModule}\label{wxmodulector}
  83
  84 \func{}{wxModule}{\void}
  85
  86 Constructs a wxModule object.
  87
  88
  89 \membersection{wxModule::\destruct{wxModule}}\label{wxmoduledtor}
  90
  91 \func{}{\destruct{wxModule}}{\void}
  92
  93 Destructor.
  94
  95
  96 \membersection{wxModule::AddDependency}\label{wxmoduleadddependency}
  97
  98 \func{void}{AddDependency}{\param{wxClassInfo * }{dep}}
  99
 100 \func{void}{AddDependency}{\param{const char * }{classname}}
 101
 102 Call this function from the constructor of the derived class. \arg{dep} must be
 103 the \helpref{CLASSINFO}{classinfo} of a wxModule-derived class and the
 104 corresponding module will be loaded \emph{before} and unloaded \emph{after}
 105 this module.
 106
 107 The second version of this function allows a dependency to be added by
 108 name without access to the class info.  This is useful when a module is
 109 declared entirely in a source file and there is no header for the declaration
 110 of the module needed by \helpref{CLASSINFO}{classinfo}, however errors are
 111 not detected until run-time, instead of compile-time, then.
 112
 113 Note that circular dependencies are detected and result in a fatal error.
 114
 115 \wxheading{Parameters}
 116
 117 \docparam{dep}{The class information object for the dependent module.}
 118
 119 \docparam{classname}{The class name of the dependent module.}
 120
 121
 122 \membersection{wxModule::OnExit}\label{wxmoduleonexit}
 123
 124 \func{virtual void}{OnExit}{\void}
 125
 126 Provide this function with appropriate cleanup for your module.
 127
 128
 129 \membersection{wxModule::OnInit}\label{wxmoduleoninit}
 130
 131 \func{virtual bool}{OnInit}{\void}
 132
 133 Provide this function with appropriate initialization for your module. If the function
 134 returns false, wxWidgets will exit immediately.
 135