UIView not redrawing, but elements become misplaced

Question

I'm having an issue with my app's layout which is a bit tricky to explain. When the app first starts, this is what I'm showing:

After the user taps "Create Profile", I animate those buttons and show a registration form instead:

Needless to say, the buttons are now not in their "natural" position. Note, however, that the text fields are - that's where I have placed them in the storyboard, but when the view first loads I hide them. The animations are working great, but then I needed to scroll my view up when the user gives focus to a text field and the keyboard hides the field. The details of how to trigger the bug are a bit hard to explain, so I managed to boil it down to what seems to be a redraw event, except that it isn't... Let me try and explain that.

First of all, here's what happens when the keyboard is about to show:

- (void)keyboardWillShow:(NSNotification*)notification
{
    CGRect frame = self.view.frame;
    frame.size.height -= 1;
    self.view.frame = frame;
}

Notice that this is a test only, probably the minimal I found that would still trigger the bug. All it does is resize the view. I would expect the view to be exactly as it was, with one less pixel, right? Wrong. Here's what I get:

That is, all elements returned to their "natural" positions, completely ignoring their previous positions. My first guess was that it would seem that the window is redrawing, so I tried this:

- (void)drawRect:(CGRect)rect
{
    [super drawRect:rect];
    NSLog(@"View was drawn");
}

But this only triggers when the window is first drawn, not when this strange behaviour happens. To understand what I mean by "natural position", here's what I have in storyboard:

You can also see that I'm not using constraints and the underlying structure of my view:

The full code for the entire setup is quite extensive, so pretty much not practical at all to show. However, how I animate the subviews resumes to changing their frame as I did in keyboardWillShow, and setting their positions to whatever I need.

Any ideas?

Answer 1

So you're using storyboards and you have "Use AutoLayout" set to false for your entire storyboard?

In that case your app is using "struts and springs" style placement rules. You're going to have to debug those.

It's a bit hard to describe everything in a view controller in a post. It's easier to go over it in IB. Perhaps you can write a utility function that logs all the autoresizingMask values for the views in your view controller, and go over those, and perhaps post them here describing the autoresizingMask values for each view in your original post.