On Jan 15, 2010, at 16:16:15, David Duncan wrote: > On Jan 15, 2010, at 4:10 PM, Rick Mann wrote: > >>> If not, this could be done (with performance penalty) using the layer's >>> mask property. Simplest way I can think is to make a new layer, assign the >>> contents of the parent layer to that new layer's contents, then assign that >>> layer as the mask of all subviews. This may require a bit of futzing around >>> to get right however. >> >> The subviews will consist of a UIScrollView and a set of UIButtons. >> Generally, I'd like to avoid subclassing them, if possible. I'm implementing >> a control with behaviors very similar to a horizontal UIPickerView. >> Unfortunately, it lives in a non-rectangular shape, and the surrounding >> elements are transparent and should NOT show the control underneath. > > > I don't see any reason why the mask property wouldn't work for that, as log > as the performance is acceptable to you (I believe using a mask will cause an > offscreen render to occur). That said, if you can possibly invert this (that > is, invert the mask and draw the content *above* the others) you should have > better performance. > > That and I think I spoke a little fast on the exact usage of the mask – iirc, > you should only need to apply it to a common parent and it should affect all > children as well.
Hmm. I tried some experiments with your suggestion, and seemed to be getting masking with the inverse of what I specified. So I looked at the docs for the mask property, and there's this note: "iPhone OS Note: As a performance consideration, iPhone OS does not support the mask property." It's clearly doing something, but it's not clear that it's doing what I want. Oh. It's working in the simulator, I bet it won't work on the phone, and it still causes a problem: it doesn't make the masked-out areas transparent. Thanks, though. -- Rick _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
