add wxAppConsoleBase::OnEventLoopEnter/Exit callbacks; add wxEventLoopBase::IsMain() and wxAppConsoleBase::GetMainLoop() helpers

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@59132 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/app.h

@@ -91,6 +91,14 @@ public:
     */
     virtual int FilterEvent(wxEvent& event);
 
+    /**
+        Returns the main event loop instance, i.e. the event loop which is started
+        by OnRun() and which dispatches all events sent from the native toolkit
+        to the application (except when new event loops are temporarily set-up).
+        The returned value maybe @NULL. Put initialization code which needs a
+        non-@NULL main event loop into OnEventLoopEnter().
+    */
+    wxEventLoopBase* GetMainLoop() const;
 
     /**
         This function simply invokes the given method @a func of the specified
@@ -254,6 +262,22 @@ public:
     */
     virtual bool OnCmdLineParsed(wxCmdLineParser& parser);
 
+    /**
+        Called by wxEventLoopBase::SetActive(): you can override this function
+        and put here the code which needs an active event loop.
+
+        Note that this function is called whenever an event loop is activated;
+        you may want to use wxEventLoopBase::IsMain() to perform initialization
+        specific for the app's main event loop.
+    */
+    virtual void OnEventLoopEnter(wxEventLoopBase* loop);
+
+    /**
+        Called by wxEventLoopBase::OnExit() for each event loop which
+        is exited.
+    */
+    virtual void OnEventLoopExit(wxEventLoopBase* loop);
+
     /**
         This function is called if an unhandled exception occurs inside the main
         application event loop. It can return @true to ignore the exception and to

interface/wx/evtloop.h

@@ -12,9 +12,16 @@
 
     Base class for all event loop implementations.
 
+    An event loop is a class which queries the queue of native events sent
+    to the wxWidgets application and dispatches them to the appropriate
+    wxEvtHandlers.
+
     An object of this class is created by wxAppTraits::CreateEventLoop() and
     used by wxApp to run the main application event loop.
 
+    You can create your own event loop if you need, provided that you restore
+    the main event loop once yours is destroyed (see wxEventLoopActivator).
+
     @library{wxbase}
     @category{appmanagement}
 
@@ -37,9 +44,16 @@ public:
         Called by wxEventLoopActivator, use an instance of this class instead
         of calling this method directly to ensure that the previously active
         event loop is restored.
+
+        Results in a call to wxAppConsole::OnEventLoopEnter.
      */
     static void SetActive(wxEventLoopBase* loop);
 
+    /**
+        Returns @true if this is the main loop executed by wxApp::OnRun().
+    */
+    bool IsMain() const;
+
 
     /**
         @name Dispatch and processing
@@ -193,7 +207,7 @@ public:
     //@{
 
     /**
-        Returns @true if called from inside Yield().
+        Returns @true if called from inside Yield() or from inside YieldFor().
     */
     virtual bool IsYielding() const;
 
@@ -261,7 +275,7 @@ protected:
         happens normally (because of Exit() call) or abnormally (because of an
         exception thrown from inside the loop).
 
-        Default version does nothing.
+        The default implementation calls wxAppConsole::OnEventLoopExit.
      */
     virtual void OnExit();
 };