Added wxBORDER_THEME, wxWindow::GetDefaultBorderForControl(), wxWindow::CanApplyThemeBorder().

wxTextCtrl and wxSearchCtrl now get the correct border on wxMSW, and the wxRichTextCtrl sample
also now demonstrates correct borders.



git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@47927 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/toplevel.h

@@ -107,6 +107,9 @@ public:
     // window proc for the frames
     WXLRESULT MSWWindowProc(WXUINT message, WXWPARAM wParam, WXLPARAM lParam);
 
+    // returns true if the platform should explicitly apply a theme border
+    virtual bool CanApplyThemeBorder() const { return false; }
+
 protected:
     // common part of all ctors
     void Init();