This article does not apply to anyone who assumed office as a justice of the Supreme Court, a judge of the Court of Civil Appeals, a judge of the Court of Criminal Appeals, or a circuit judge before July 30, 1979. This article also does not apply to anyone who assumed office as a district judge before July 30, 1979, and later assumed or assumes office as a justice of the Supreme Court, a judge of the Court of Civil Appeals, a judge of the Court of Criminal Appeals, or a circuit judge.