interface/wx/module.h

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