How can I do custom drawing on part of a view that also contains buttons and other controls?
<p>I've tried this demo code and gotten it to work fine:</p>

<p><a href="http://www.techotopia.com/index.php/An_iPhone_Graphics_Drawing_Tutorial_using_Quartz_2D" rel="nofollow">http://www.techotopia.com/index.php/An_iPhone_Graphics_Drawing_Tutorial_using_Quartz_2D</a></p>

<p>What I'd like to do, however, is to do the same custom drawing onto a panel or canvas of some sort sitting on the view (instead of drawing on the view itself).  I'd also like to have other controls (like buttons) on the same view, and have the button clicks control the actual drawing.</p>

<p>Is there an easy way to do this?</p>
