Re: force rendering of views off screen
Re: force rendering of views off screen
- Subject: Re: force rendering of views off screen
- From: Martin Glaß <email@hidden>
- Date: Thu, 24 Jun 2010 11:51:15 +0200
yes, you're describing what i want.
the problem is that a subview (page) of the main scrollview only calls
-drawLayer:inContext: if the user flips to a page, thus that
particular page moving into the view/becoming visible.
additionally, if the user scrolls through the pages very fast, no
content is visible until all CATiledLayers of a page's content gets
drawn calling the above method.
I am using CATiledLayers to improve performance during drawing and
zooming (each page can be zoomed, additionally).
rather difficult to explain, actually.
hope that was clear?
i think about adding/removing subviews like you do in your app - but
what about performance if the user scrolls fast?
thanks!
- m
2010/6/23 Matt Neuburg <email@hidden>:
> On Wed, 23 Jun 2010 14:27:43 +0200, Martin Gla? <email@hidden>
> said:
>>i am developing an ipad app which offers a full screen UIScrollView which
>>itself has several subviews, representing the pages the user can flip
>>through.
>>problem is: every subview renders a pdf page and does so on-demand, lazy,
>>when it slides into view.
>>i would like the subview right and left from the currently visible view
>>being pre-rendered (like facebook's app does in galleries) so that the user
>>doesn't see all the CATiledLayers be fading in.
>
> This might not be any help, because I might not be understanding the problem
> correctly. But...
>
> I have an app where the user scrolls between hundreds of "pages" in a paged
> scroll view, but only three of them are ever drawn at any one moment: the
> one the user is looking at, and the ones to the right and left of that.
> Every time the user scrolls by a page, I rip out all others and put in the
> new left or right as needed.
>
> Thus I don't understand why you don't just let "lazy" mean what I mean above
> - i.e., "render it when it is the subview right or left from the currently
> visible view" rather than waiting until "it slides into view". It isn't
> "offscreen" if it's being drawn into the scroll view's content.
>
> Also, although I have not checked this, the ScrollViewSuite example might be
> useful here.
>
> m.
>
> --
> matt neuburg, phd = email@hidden, <http://www.tidbits.com/matt/>
> A fool + a tool + an autorelease pool = cool!
> AppleScript: the Definitive Guide - Second Edition!
> http://www.tidbits.com/matt/default.html#applescriptthings
>
>
>
>
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