iOS 7 back swipe gesture and keyboard dismissal - cocoa-touch

Question

I have a standard UINavigationViewController with a standard UIInteractivePopGestureRecognizer for iOS 7. I also have these well known and widely-used methods:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillShow:) name:UIKeyboardWillShowNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
They work like this:
- (void)keyboardWillShow:(NSNotification *)notification{
CGFloat keyboardSlideDuration = [[[notification userInfo] objectForKey: UIKeyboardAnimationDurationUserInfoKey] floatValue];
UIViewAnimationOptions keyboardAnimationCurve = [[notification userInfo][UIKeyboardAnimationCurveUserInfoKey] integerValue]<<16;
if (keyboardIsUp || isAnimating) return;
isAnimating = YES;
[UIView animateWithDuration:keyboardSlideDuration delay:0 options:(keyboardAnimationCurve | UIViewAnimationOptionBeginFromCurrentState) animations:^{
_topConstraint.constant -= kTopConstraintR4Ratio;
[self.view layoutIfNeeded];
}completion:^(BOOL finished){
keyboardIsUp = YES;
isAnimating = NO;
}];
}
- (void)keyboardWillHide:(NSNotification *)notification{
CGFloat keyboardSlideDuration = [[[notification userInfo] objectForKey: UIKeyboardAnimationDurationUserInfoKey] floatValue];
UIViewAnimationOptions keyboardAnimationCurve = [[notification userInfo][UIKeyboardAnimationCurveUserInfoKey] integerValue]<<16;
if (isAnimating) return;
isAnimating = YES;
[UIView animateWithDuration:keyboardSlideDuration delay:0 options:(keyboardAnimationCurve | UIViewAnimationOptionBeginFromCurrentState) animations:^{
_topConstraint.constant = topConstraintOriginalValue;
[self.view layoutIfNeeded];
} completion:^(BOOL finished) {
keyboardIsUp = NO;
isAnimating = NO;
}];
}
The thing is that UIView animateWithDuration is triggered without any respect to duration when I swipe the view back with a gesture. The whole view turns into a mess - it animates slowly when I pop the view, but when the gesture isn't finished - the view jumps up.
It looks like this:
How do I get rid of this strange behavior? I don't want the view to move during the transition and I want it to stay still.
EDIT:
You can download the sample project using the link here:
https://www.dropbox.com/s/034lfy49ru4pelf/SampleProject.zip

Answer 1

Easy hack:
BOOL needAdjustContstrain;
Set needAdjustContstrain to YES in keyboardWillShow:
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
if (needAdjustContstrain) {
_topContstraint.constant -=40;
}
}

Answer 2

you need to call the layoutIfneeded method before the animation block . Check out the code below :
- (void)keyboardWillHide:(NSNotification *)notification{
CGFloat keyboardSlideDuration = [[[notification userInfo] objectForKey: UIKeyboardAnimationDurationUserInfoKey] floatValue];
UIViewAnimationOptions keyboardAnimationCurve = [[notification userInfo][UIKeyboardAnimationCurveUserInfoKey] integerValue]<<16;
if (isAnimating) return;
isAnimating = YES;
[self.view layoutIfNeeded];
[UIView animateWithDuration:keyboardSlideDuration delay:0 options:(keyboardAnimationCurve | UIViewAnimationOptionBeginFromCurrentState) animations:^{
_topContstraint.constant = 89;
//
} completion:^(BOOL finished) {
keyboardIsUp = NO;
isAnimating = NO;
}];}
Please check the link