make IsEnabled() return false even if the window parent, and not the window itself, is disabled and added IsThisEnabled() implementing the old IsEnabled() behaviour; also significantly simplify the window state management code in all ports by factoring out the common parts in wxWindowBase

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@45031 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/window.h

@@ -61,7 +61,7 @@ public:
     virtual void Lower();
 
     virtual bool Show( bool show = true );
-    virtual bool Enable( bool enable = true );
+    virtual void DoEnable( bool enable );
 
     virtual void SetWindowStyleFlag( long style );
 
@@ -141,11 +141,6 @@ public:
     // For compatibility across platforms (not in event table)
     void OnIdle(wxIdleEvent& WXUNUSED(event)) {}
 
-    // wxGTK-specific: called recursively by Enable,
-    // to give widgets an opportunity to correct their colours after they
-    // have been changed by Enable
-    virtual void OnParentEnable( bool WXUNUSED(enable) ) {}
-
     // Used by all window classes in the widget creation process.
     bool PreCreation( wxWindowGTK *parent, const wxPoint &pos, const wxSize &size );
     void PostCreation();