def dragEnterEvent(self, e):
        editor = self.parent()._qt4_editor

        if editor.factory.binding:
            data = getattr(clipboard, 'node', None)
        else:
            md = e.mimeData()

            if not isinstance(md, PyMimeData):
                return

            data = md.instance()

        try:
            editor.object.base_trait(editor.name).validate(editor.object,
                    editor.name, data)
            e.acceptProposedAction()
        except:
            pass


# Define the Text and ReadonlyEditor for use by the editor factory.
Handles a Python object being dragged over the tree.
dataset/ETHPy150Open enthought/traitsui/traitsui/qt4/drop_editor.py/_DropEventFilter.dragEnterEvent