iOS 8 custom keyboard height change from portrait, then to landscape and back to portrait

Question

We can create custom keyboard like this code in viewdidload as shown in apple developer site.

self.nextKeyboardButton = [UIButton buttonWithType:UIButtonTypeSystem];

[self.nextKeyboardButton setTitle:NSLocalizedString(@"Next Keyboard", @"Title for 'Next Keyboard' button") forState:UIControlStateNormal];
[self.nextKeyboardButton sizeToFit];
self.nextKeyboardButton.translatesAutoresizingMaskIntoConstraints = NO;

[self.nextKeyboardButton addTarget:self action:@selector(advanceToNextInputMode) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:self.nextKeyboardButton];

NSLayoutConstraint *nextKeyboardButtonLeftSideConstraint = [NSLayoutConstraint constraintWithItem:self.nextKeyboardButton attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeLeft multiplier:1.0 constant:0.0];
NSLayoutConstraint *nextKeyboardButtonBottomConstraint = [NSLayoutConstraint constraintWithItem:self.nextKeyboardButton attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeBottom multiplier:1.0 constant:0.0];
[self.view addConstraints:@[nextKeyboardButtonLeftSideConstraint, nextKeyboardButtonBottomConstraint]];

However, there is 1 problem. When we run that program in portrait, the height of custom keyboard is around 220. Then we change to landscape. It is less than 220. Strangely, when I go back to portrait view, the height is no longer 220 and it is same as landscape height. It never go back to original height. So, is there a way to change the height of view to which we will add our subview?

Answer 1

That's probably a bug with apple's keyboard constraints problem, when rotating I'm seeing these messages in log:

 Unable to simultaneously satisfy constraints.
        Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
    (
        "<NSLayoutConstraint:0xfd04d80 V:[_UIKBCompatInputView:0xf97a580(216)]>",
        "<NSLayoutConstraint:0xe325bf0 V:[_UIKBCompatInputView:0xf97a580(162)]>"
    )

    Will attempt to recover by breaking constraint 
    <NSLayoutConstraint:0xfd04d80 V:[_UIKBCompatInputView:0xf97a580(216)]>

    Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
    The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

I already filed a bug for it.