+#if wxUSE_VALIDATORS
+
+namespace
+{
+
+// This class encapsulates possibly recursive iteration on window children done
+// by Validate() and TransferData{To,From}Window() and allows to avoid code
+// duplication in all three functions.
+class ValidationTraverserBase
+{
+public:
+ wxEXPLICIT ValidationTraverserBase(wxWindowBase* win)
+ : m_win(static_cast<wxWindow*>(win))
+ {
+ }
+
+ // Traverse all the direct children calling OnDo() on them and also all
+ // grandchildren if wxWS_EX_VALIDATE_RECURSIVELY is used, calling
+ // OnRecurse() for them.
+ bool DoForAllChildren()
+ {
+ const bool recurse = m_win->HasExtraStyle(wxWS_EX_VALIDATE_RECURSIVELY);
+
+ wxWindowList& children = m_win->GetChildren();
+ for ( wxWindowList::iterator i = children.begin();
+ i != children.end();
+ ++i )
+ {
+ wxWindow* const child = static_cast<wxWindow*>(*i);
+ wxValidator* const validator = child->GetValidator();
+ if ( validator && !OnDo(validator) )
+ {
+ return false;
+ }
+
+ // Notice that validation should never recurse into top level
+ // children, e.g. some other dialog which might happen to be
+ // currently shown.
+ if ( recurse && !child->IsTopLevel() && !OnRecurse(child) )
+ {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ // Give it a virtual dtor just to suppress gcc warnings about a class with
+ // virtual methods but non-virtual dtor -- even if this is completely safe
+ // here as we never use the objects of this class polymorphically.
+ virtual ~ValidationTraverserBase() { }
+
+protected:
+ // Called for each child, validator is guaranteed to be non-NULL.
+ virtual bool OnDo(wxValidator* validator) = 0;
+
+ // Called for each child if we need to recurse into its children.
+ virtual bool OnRecurse(wxWindow* child) = 0;
+
+
+ // The window whose children we're traversing.
+ wxWindow* const m_win;
+
+ wxDECLARE_NO_COPY_CLASS(ValidationTraverserBase);
+};
+
+} // anonymous namespace
+
+#endif // wxUSE_VALIDATORS
+