<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def project_name_changed(self, widget, data=None):
 """ Function controls whether run button is enabled """

        if widget.get_text() != "":
            self.run_btn.set_sensitive(True)
        else:
            self.run_btn.set_sensitive(False)
        self.update_full_label()