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Re: How does CATiledLayer determine what it needs to draw? Steven Woolgar Tue Jun 02 09:01:30 2009

On Tue, 2 Jun 2009 07:16:38 -0700, Shawn Erickson wrote:
> On Tue, Jun 2, 2009 at 7:08 AM, Hamish Allan <[EMAIL PROTECTED]> wrote:
>> I glanced upon this question in a previous thread, but I fear it got
>> lost in the noise of my other lines of enquiry, so I thought I'd give
>> it another go with its very own subject line :)
>> 
>> I've now got a UIScrollView with several CATiledLayers in it (as
>> sublayers of its content view's layer), and for the most part,
>> everything works fine. However, occasionally the layers simply fail to
>> realise that they need to draw, particularly at startup. Scrolling a
>> little gives them the push they need, though some need a little more
>> than others (this seems to be deterministic, but I haven't worked out
>> a pattern). If I change the layers to be plain CALayers rather than
>> CATiledLayers, they always draw correctly.
> 
> Why do you have several tiled layers? I am trying to better understand
> the view hierarchy under the scroll view.

In my case, I have two tiled layers because I draw something quick in 
one layer
and something slow in another.  This way you never get empty screen 
syndrome
for very long since the fast drawing layer draws way before the slow 
drawing on does.




W.
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