cleanup the Win32 window classes registration code: remove global variables and register the window classes we use on demand to avoid registering MDI or GL classes unnecessarily

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@57030 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/app.h

@@ -25,8 +25,6 @@ class WXDLLIMPEXP_FWD_BASE wxLog;
 // a new App object to start application
 class WXDLLIMPEXP_CORE wxApp : public wxAppBase
 {
-    DECLARE_DYNAMIC_CLASS(wxApp)
-
 public:
     wxApp();
     virtual ~wxApp();
@@ -50,13 +48,40 @@ public:
     virtual bool OnExceptionInMainLoop();
 #endif // wxUSE_EXCEPTIONS
 
+    // MSW-specific from now on
+    // ------------------------
+
+    // this suffix should be appended to all our Win32 class names to obtain a
+    // variant registered without CS_[HV]REDRAW styles
+    static const wxChar *GetNoRedrawClassSuffix() { return _T("NR"); }
+
+    // get the name of the registered Win32 class with the given (unique) base
+    // name: this function constructs the unique class name using this name as
+    // prefix, checks if the class is already registered and registers it if it
+    // isn't and returns the name it was registered under (or NULL if it failed)
+    //
+    // the registered class will always have CS_[HV]REDRAW and CS_DBLCLKS
+    // styles as well as any additional styles specified as arguments here; and
+    // there will be also a companion registered class identical to this one
+    // but without CS_[HV]REDRAW whose name will be the same one but with
+    // GetNoRedrawClassSuffix()
+    //
+    // the background brush argument must be either a COLOR_XXX standard value
+    // or (default) -1 meaning that the class paints its background itself
+    static const wxChar *GetRegisteredClassName(const wxChar *name,
+                                                int bgBrushCol = -1,
+                                                int extraStyles = 0);
+
+    // return true if this name corresponds to one of the classes we registered
+    // in the previous GetRegisteredClassName() calls
+    static bool IsRegisteredClassName(const wxString& name);
+
 protected:
     int    m_printMode; // wxPRINT_WINDOWS, wxPRINT_POSTSCRIPT
 
 public:
-    // Implementation
-    static bool RegisterWindowClasses();
-    static bool UnregisterWindowClasses();
+    // unregister any window classes registered by GetRegisteredClassName()
+    static void UnregisterWindowClasses();
 
 #if wxUSE_RICHEDIT
     // initialize the richedit DLL of (at least) given version, return true if
@@ -79,6 +104,7 @@ public:
 protected:
     DECLARE_EVENT_TABLE()
     DECLARE_NO_COPY_CLASS(wxApp)
+    DECLARE_DYNAMIC_CLASS(wxApp)
 };
 
 #ifdef __WXWINCE__