added possibility to specify modules dependencies

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39677 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -49,6 +49,7 @@ All:
 - Added wxStandardPaths::GetDocumentsDir() (Ken Thomases)
 - Added wxStringTokenizer::GetLastDelimiter(); improved documentation.
 - Fixed wxTextFile in Unicode build
+- Added possibility to specify dependencies for a wxModule
 - Speed improvements to wxRegEx when matching is done in a loop such as
   during a search and replace.
 - Fix regerror and regfree name conficts when built-in regex and system regex

docs/latex/wx/module.tex

@@ -1,14 +1,16 @@
 \section{\class{wxModule}}\label{wxmodule}
 
-The module system is a very simple mechanism to allow applications (and parts of wxWidgets itself) to
-define initialization and cleanup functions that are automatically called on wxWidgets
-startup and exit.
+The module system is a very simple mechanism to allow applications (and parts
+of wxWidgets itself) to define initialization and cleanup functions that are
+automatically called on wxWidgets startup and exit.
 
-To define a new kind of module, derive a class from wxModule, override the OnInit and OnExit functions,
-and add the DECLARE\_DYNAMIC\_CLASS and IMPLEMENT\_DYNAMIC\_CLASS to header and implementation files
-(which can be the same file). On initialization, wxWidgets will find all classes derived from wxModule,
-create an instance of each, and call each OnInit function. On exit, wxWidgets will call the OnExit
-function for each module instance.
+To define a new kind of module, derive a class from wxModule, override the
+\helpref{OnInit}{wxmoduleoninit} and \helpref{OnExit}{wxmoduleonexit} 
+functions, and add the DECLARE\_DYNAMIC\_CLASS and IMPLEMENT\_DYNAMIC\_CLASS to
+header and implementation files (which can be the same file). On
+initialization, wxWidgets will find all classes derived from wxModule, create
+an instance of each, and call each OnInit function. On exit, wxWidgets will
+call the OnExit function for each module instance.
 
 Note that your module class does not have to be in a header file.
 
@@ -18,17 +20,31 @@ For example:
   // A module to allow DDE initialization/cleanup
   // without calling these functions from app.cpp or from
   // the user's application.
-
   class wxDDEModule: public wxModule
   {
-  DECLARE_DYNAMIC_CLASS(wxDDEModule)
   public:
-      wxDDEModule() {}
-      bool OnInit() { wxDDEInitialize(); return true; };
-      void OnExit() { wxDDECleanUp(); };
+      wxDDEModule() { }
+      virtual bool OnInit() { wxDDEInitialize(); return true; };
+      virtual void OnExit() { wxDDECleanUp(); };
+
+  private:
+      DECLARE_DYNAMIC_CLASS(wxDDEModule)
   };
 
   IMPLEMENT_DYNAMIC_CLASS(wxDDEModule, wxModule)
+
+
+  // Another module which uses DDE in its OnInit()
+  class MyModule: public wxModule
+  {
+  public:
+      wxDDEModule() { AddDependency(CLASSINFO(wxDDEModule)); }
+      virtual bool OnInit() { ... code using DDE ... }
+      virtual void OnExit() { ... }
+
+  private:
+      DECLARE_DYNAMIC_CLASS(wxDDEModule)
+  };
 \end{verbatim}
 
 \wxheading{Derived from}
@@ -41,28 +57,47 @@ For example:
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 
+
 \membersection{wxModule::wxModule}\label{wxmodulector}
 
 \func{}{wxModule}{\void}
 
 Constructs a wxModule object.
 
+
 \membersection{wxModule::\destruct{wxModule}}\label{wxmoduledtor}
 
 \func{}{\destruct{wxModule}}{\void}
 
 Destructor.
 
+
+\membersection{wxModule::AddDependency}\label{wxmoduleoninit}
+
+\func{void}{AddDependency}{\param{wxClassInfo * }{dep}}
+
+Call this function from the constructor of the derived class. \arg{dep} must be
+the \helpref{CLASSINFO}{classinfo} of a wxModule-derived class and the
+corresponding module will be loaded \emph{before} and unloaded \emph{after}
+this module.
+
+Note that circular dependencies are detected and result in a fatal error.
+
+\wxheading{Parameters}
+
+\docparam{dep}{The class information object for the dependent module.}
+
+
 \membersection{wxModule::OnExit}\label{wxmoduleonexit}
 
 \func{virtual void}{OnExit}{\void}
 
 Provide this function with appropriate cleanup for your module.
 
+
 \membersection{wxModule::OnInit}\label{wxmoduleoninit}
 
 \func{virtual bool}{OnInit}{\void}
 
 Provide this function with appropriate initialization for your module. If the function
 returns false, wxWidgets will exit immediately.
-