Change to the selected document and hide this widget.

def item_selected(self, item=None):
        """Change to the selected document and hide this widget."""
        if item is None:
            item = self.currentItem()

        # stack history is in inverse order
        try:
            index = self.stack_history[-(self.currentRow()+1)]
        except IndexError:
            pass
        else:
            self.editor.set_stack_index(index)
            self.editor.current_changed(index)
        self.hide()