Re: Profound UITableView rendering-performance problem, but only at certain positions?
Re: Profound UITableView rendering-performance problem, but only at certain positions?
- Subject: Re: Profound UITableView rendering-performance problem, but only at certain positions?
- From: Gavin Stokes <email@hidden>
- Date: Mon, 23 Jul 2012 14:03:00 -0700
On Mon, Jul 23, 2012 at 8:16 AM, Fritz Anderson <email@hidden>wrote:
> I think the first problem you should concentrate on should be the
> multiply-overlaid drawings. It's hard to tell what's going on unless you
> share some code, or at least your design, so I can only ask general
> questions.
>
Thanks for your response. The code is quite simple, so I'm happy to
provide it. But, because the occurrence of the problem depends entirely on
the existence of a partially exposed row in a previous section at the top
of the screen, I don't think any of this processing has anything to do with
the problem. There's only about a 50-pixel danger zone of scroll position
where it occurs, and that zone moves with row height, but not by any
discernible pattern.
I have Location Services set to give me heading updates every 10 degrees.
When my view controller gets called with a heading update, I do:
[self.stashTableView reloadRowsAtIndexPaths:[self.stashTableView
indexPathsForVisibleRows] withRowAnimation:UITableViewRowAnimationNone];
When the tableview calls me with willDisplayCell, and I do a bit of math to
combine the current heading with the angle toward a point of interest.
Then I tell the cell to rotate the arrow image, which is simply a
UIImageView:
CGAffineTransform rotation = CGAffineTransformMakeRotation(degrees * (M_PI
/ 180));
[self.thumbImageView setTransform:rotation];
That's it. Works great except for a very limited range of scroll offsets.
_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden