How do I use CALayer with the iPhone?

Question

Currently, I have a UIView subclass that \"stamps\" a single 2px by 2px CGLayerRef across the screen, up to 160 x 240 times.

I currently animate this by moving the UIVie

Answer 1

What CALayer methods are you seeing that don't work on iPhone?

As one example, I tried implementing the grid demo here, without much luck. It looks like CAConstraintLayoutManager and CAConstraint are not available in QuartzCore.h.

In another attempt, I tried a very simple, small 20x20 CALayer object as a sublayer of my UIView's layer property, but that didn't show up.

Right now, I have a custom UIView of which I override the drawRect method. In drawRect I grab a context and render two types of CGLayerRefs:

At "off" cells I draw the background color across the entire 320x480 canvas.

At "on" cells, I either draw a single CGLayerRef across a grid of 320x480 pixels (initialization) or across a 320x2 row (animation).

During animation, I make a UIImageView clip view from 320x478 pixels, and draw a single row. This "pushes" my bitmap up the screen two pixels at a time.

Basically, I'd like to test whether or not using CALayer will accomplish two things:

1. Make my rendering faster, if CALayer has less overhead than what I'm doing now
2. Make my animation smoother, by letting me transition a layer up the screen smoothly

Unfortunately, I can't seem to get a basic CALayer working at the moment, and haven't found a good chunk of sample code to look at and play with.