Why is animated UIButton's position reset when clicked? - ios

Question

Short description: When the keyboard is shown I translate a button up, but upon clicking the button it pops back down to its original position.
Long description: I have two buttons, one on top of the other. One is hidden until certain criteria are met, then it becomes visible and the other is hidden.
#property (weak, nonatomic) IBOutlet UIButton *skipButton;
#property (weak, nonatomic) IBOutlet UIButton *saveButton;
#property (assign, nonatomic) BOOL saveButtonEnabled;
#property (assign, readonly, nonatomic) CGRect fieldContainerDefaultFrame;
#property (assign, readonly, nonatomic) CGRect skipButtonDefaultFrame;
When view loads I cache the default positions
- (void)viewDidLoad
{
[super viewDidLoad];
...
_fieldContainerDefaultFrame = self.fieldContainerView.frame;
_skipButtonDefaultFrame = self.skipButton.frame;
[self.saveButton setHidden:YES];
self.saveButtonEnabled = NO;
}
The buttons are wired to outlets correctly and these are their "touch up inside" actions
#pragma mark - Actions
- (IBAction)didPressSaveButton:(id)sender
{
// Code here to persist data
// Code here to push segue to next scene
}
- (IBAction)didPressSkipButton:(id)sender
{
// Code here to push segue to next scene
}
Here are the methods that respond to the keyboard notifications. I do register for the notifications I'm just not including that code. (There is no issue there, all this stuff gets run correctly.)
NOTE: Both buttons are contained in the same "container" frame (along with other fields), which translates up. The buttons translate up an additional amount. The translation works in general, the only issue is the reseting behavior of the button upon click.
#pragma mark - Notification handlers
- (void)handleKeyboardWillShowNotification:(NSNotification *)note
{
if([self.bioTextView isFirstResponder])
{
CGRect newFieldContainerFrame = self.fieldContainerDefaultFrame;
CGRect newSkipButtonFrame = self.skipButtonDefaultFrame;
newFieldContainerFrame.origin.y += AGSTSignupDetailsFieldContainerEditingOffset;
newSkipButtonFrame.origin.y += AGSTSignupDetailsSkipButtonEditingOffset;
NSTimeInterval duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
UIViewAnimationCurve animationCurve = [note.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue];
[UIView animateWithDuration:duration animations:^{
[UIView setAnimationCurve:animationCurve];
self.fieldContainerView.frame = newFieldContainerFrame;
self.skipButton.frame = newSkipButtonFrame;
self.saveButton.frame = newSkipButtonFrame;
}];
}
}
- (void)handleKeyboardWillHideNotification:(NSNotification *)note
{
NSTimeInterval duration = [note.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue];
UIViewAnimationCurve animationCurve = [note.userInfo[UIKeyboardAnimationCurveUserInfoKey] integerValue];
[UIView animateWithDuration:duration animations:^{
[UIView setAnimationCurve:animationCurve];
self.fieldContainerView.frame = self.fieldContainerDefaultFrame;
self.skipButton.frame = self.skipButtonDefaultFrame;
self.saveButton.frame = self.skipButtonDefaultFrame;
}];
}
I'd appreciate any insights or suggestions as to how to fix the bug or how to craft a better solution. Thanks.

Answer 1

Okay, I fixed the problem. While I appreciate rob mayoff's response as an indication of better practices (i.e., don't set frames when using autolayout), that was not the actual cause of the problem in my case, thus I don't consider my Q&A to be a duplicate of anything I could find. I'm going to post this answer in case someone else runs across a similar problem.
It turns out, as I suspected earlier this morning, that the button's push segue did two mutually incompatible things: (1) it caused the keyboard to disappear, which caused the fields to be translated downward; and (2) it caused the whole scene to animate away as the new VC comes into place, which apparently cancelled all pending animations (i.e., the translation) and caused those translations to abruptly jump to their destination states.
The quickest solution was to set a BOOL didPressSaveButton to NO on viewDidLoad and only set it to YES once the button is pushed, and then check that BOOL before every relevant translation animation: if the BOOL is NO, go ahead and do the animation, otherwise do nothing. This will prevent the abrupt final animation before the push segue.
The better solution, and one I will implement soon, will be to replace my use of frames with autolayout constraints.