ref: cdb993dffbd3050112b2fc3a93d7f51eead2ec74
parent: 91c36955994c33885bb695aea30d4746c35f4c09
author: phil9 <telephil9@gmail.com>
date: Fri Feb 4 13:15:38 EST 2022
improve selection in index cleanup the code, fix some redraw issues and limit the number of full redraws.