Implement wxButton::SetDefault to call SetDefaultItem on the top-level window.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@48529 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/cocoa/button.h

@@ -59,6 +59,7 @@ public:
     wxString GetLabel() const;
     void SetLabel(const wxString& label);
     wxSize DoGetBestSize() const;
+    virtual void SetDefault();
 };
 
 #endif

src/cocoa/button.mm

@@ -15,6 +15,7 @@
 
 #ifndef WX_PRECOMP
     #include "wx/log.h"
+    #include "wx/toplevel.h"
 #endif
 
 #include "wx/stockitem.h"
@@ -105,6 +106,16 @@ wxSize wxButton::DoGetBestSize() const
     return size;
 }
 
+void wxButton::SetDefault()
+{
+    wxTopLevelWindow * const
+        tlw = wxDynamicCast(wxGetTopLevelParent(this), wxTopLevelWindow);
+
+    wxCHECK_RET( tlw != NULL, _T("button without top level window?") );
+
+    tlw->SetDefaultItem(this);
+}
+
 static NSRect MakeNSButtonDefaultRect()
 {
     // create at (10.0,10.0) with size 20.0x20.0 (just bogus values)