This is a fantastic sample project. It’s really tidy, and it’s obvious how to reproduce the problem.
Did you file a bug at bugreport.apple.com <http://bugreport.apple.com/>? It’s a much better venue for bug reports than this list, which isn’t officially monitored by Apple for bug reports. Jamie. > On Sep 23, 2014, at 4:32 PM, Daniel Blakemore <dblakem...@pixio.com> wrote: > > I was trying to fix some (what I thought to be) minor alignment bugs that > came up during QA for one of our apps, when I stumbled on one of the more > strange bugs I've seen recently. > > In this app, the first screen presents you with the options to log in or > create an account. > The login screen is two text fields and the first part of the account > creation is one large one. > > The QA came back with a bug where the email field on the login screen > wasn't properly centered during editing: > before tapping to edit: > > > after tapping: > > > At first, I couldn't even reproduce the bug until they gave me this set of > steps: > > Launch the app > Look at the account creation screen (which sets the first textfield as > first responder automatically) > Go back the splash screen > Click the login button > start editing the text in the email box > voila, broken centering > > After rounding up the usual suspects, nothing seemed to make sense. Plus > the only way to cause it was to view an unrelated view. Not only is the > account creation screen completely different from the login screen, but > once you back out of the account creation screen, it is deallocated and > shouldn't have any effect on anything. > > Yet somehow, just having the cursor in the field was enough to spawn two > entangled particles somewhere in the depths of UIKit that linked this view > and the one that will be created (note it is not even in memory yet) when > the login view is initialized (and the original field has already been > deallocated). These two views that were never resident in memory at the > same time, used the magic of (presumably) quantum physics to communicate > across time and space with the goal of breaking my simple text centering. > > After proceeding through the five stages of grief about what I assumed to > be yet another rare, unsolvable quirk in UIKit, I found this Stack Overflow > question: > http://stackoverflow.com/questions/24184302/uitextfield-horizontal-text-alignment-text-not-centered?rq=1 > > There was some mention that the height of the field affected the > centering. This isn't my issue because the field in question has a > reasonable height. But it got me thinking, what could have caused this? > > I'm still not sure. But what I do know is that it only happens if you > start editing a UITextField where the height is set by a constraint such as > V:|-[viewInQuestion]-|. Once you begin editing that field (which itself > acts just as you would expect), you can edit the other field and observe > the jump: > This only happens the first time you begin editing the normally sized > field. Every subsequent entry into the field results in the normal > lack-of-crazy-jump that you've come to expect from UIKit. Additionally, > editing a similarly laid out text field with secureTextEntry set to TRUE > does not display the same behavior. > > For now, I can change the constraint aligning the text field which is the > source of the problem, but I thought that this discovery might be of > interest to the cocoa-dev list (and hopefully to someone at Apple ;-] ). > > As such, I created a new project from the ground up with a (mostly) minimal > setup to reproduce the bug under the conditions that I saw it (multiple > view controllers). > > That project can be found here: > https://github.com/danblakemore/QuantumEntanglement > > > -- > Daniel Blakemore > Pixio Software > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > 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: > https://lists.apple.com/mailman/options/cocoa-dev/jamie%40montgomerie.net > > This email sent to ja...@montgomerie.net _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
