use tracking rect for visible rect to support tooltip in navigation slider
use tracking rect for visible rect to support tooltip in navigation slider
WoLpH/skim,WoLpH/skim,WoLpH/skim,ycaihua/skim-app,WoLpH/skim,ycaihua/skim-app,WoLpH/skim,ycaihua/skim-app,ycaihua/skim-app,ycaihua/skim-app