def mouseMoveEvent(self, event):
        """Override Qt method.

        Show code analisis, if left button pressed select lines.
        """
        line_number = self.editor.get_linenumber_from_mouse_event(event)
        block = self.editor.document().findBlockByNumber(line_number-1)
        data = block.userData()

        # this disables pyflakes messages if there is an active drag/selection
        # operation
        check = self._released == -1
        if data and data.code_analysis and check:
            self.editor.show_code_analysis_results(line_number,
                                                   data)
        else:
            self.editor.hide_tooltip()

        if event.buttons() == Qt.LeftButton:
            self._released = line_number
            self.editor.select_lines(self._pressed, self._released)