IMPROVED the performance in drawing the background view of the panel.

[torinkwok]

Just a little adjustment : )

[shpakovski]

Hey. Does it really matter if we still rebuild the UIBezierPath every time? I believe CPU is less important resource than memory retained by the ivar :) Anyway, how about optimizing the number of steps by remembering the content rect and arrow position or at least by removing all curve points after drawing?

[torinkwok]

Okay, you are right! : P