macOS wxTextEntry::GetTextPeer fix for wxGenericComboCtrl (#1931)

* overriding GetTextPeer in generic combo control

* undo 81e3760e4a

* inlining GetTextPeer()

* moving out of line to reduce header include

include/wx/generic/combo.h

@@ -91,8 +91,8 @@ protected:
     virtual GtkEditable *GetEditable() const wxOVERRIDE { return NULL; }
     virtual GtkEntry *GetEntry() const wxOVERRIDE { return NULL; }
 #endif
-#elif defined(__WXMAC__)
+#elif defined(__WXOSX__)
-    // Looks like there's nothing we need to override here
+    virtual wxTextWidgetImpl * GetTextPeer() const wxOVERRIDE;
 #endif
 
     // For better transparent background rendering

src/generic/combog.cpp

@@ -458,6 +458,13 @@ bool wxGenericComboCtrl::IsKeyPopupToggle(const wxKeyEvent& event) const
     return false;
 }
 
+#if defined(__WXOSX__)
+wxTextWidgetImpl * wxGenericComboCtrl::GetTextPeer() const
+{
+    return m_text ? m_text->GetTextPeer() : NULL;
+}
+#endif
+
 #ifdef __WXUNIVERSAL__
 
 bool wxGenericComboCtrl::PerformAction(const wxControlAction& action,

src/generic/odcombo.cpp

@@ -988,14 +988,7 @@ void wxOwnerDrawnComboBox::DoClear()
 
     // There is no text entry when using wxCB_READONLY style, so test for it.
     if ( GetTextCtrl() )
-    {
-#ifdef __WXOSX__
-        // this has to be rerouted to the text control explicitly on macOS
-        GetTextCtrl()->Clear();
-#else
         wxTextEntry::Clear();
-#endif
-    }
 }
 
 void wxOwnerDrawnComboBox::Clear()