Odd autolayout glitch - placing a custom view using autolayout into a superview - ios

Question

I have a very odd problem with auto layout. When I place a simple, ordinary view into a superview and attach constraints to it programmatically, it works exactly as I expect. However, when I do the same thing with a custom view that itself has subviews, the constraints do not work properly.
I set up the custom view's autolayout thus:
- (void) initialiseSubviews
{
self.backgroundColor = [UIColor whiteColor];
UILabel * headerLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 0.0, self.frame.size.width, 20.0)];
headerLabel.backgroundColor = [self tintColor];
[self addSubview:headerLabel];
NSDictionary * viewDict = NSDictionaryOfVariableBindings(headerLabel);
NSArray * horiz = [NSLayoutConstraint constraintsWithVisualFormat:#"H:|-[headerLabel]-|" options:0 metrics:nil views:viewDict];
NSArray * vert = [NSLayoutConstraint constraintsWithVisualFormat:#"V:|-[headerLabel]" options:0 metrics:nil views:viewDict];
NSArray * height = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[headerLabel(20)]" options:0 metrics:nil views:viewDict];
[headerLabel addConstraints:height];
[self addConstraints:horiz];
[self addConstraints:vert];
}
+ (BOOL) requiresConstraintBasedLayout
{
return YES;
}
- (BOOL) translatesAutoresizingMaskIntoConstraints
{
return NO;
}
- (CGSize) intrinsicContentSize
{
return CGSizeMake(200.0, 120.0);
}
...and add that to a content view as follows:
- (SSNodeView *) addNodeAtPoint:(CGPoint)point
{
// Prepare the node view
SSNodeView * nodeView = [SSNodeView nodeView];
[self.gridView addSubview:nodeView];
NSDictionary * viewDict = NSDictionaryOfVariableBindings(nodeView);
NSArray * width = [NSLayoutConstraint constraintsWithVisualFormat:#"H:[nodeView(>=300)]" options:0 metrics:0 views:viewDict];
NSArray * height = [NSLayoutConstraint constraintsWithVisualFormat:#"V:[nodeView(>=200)]" options:0 metrics:0 views:viewDict];
[nodeView addConstraints:width];
[nodeView addConstraints:height];
// Set its autolayout properties
NSDictionary * metricDict = #{#"x":[NSNumber numberWithFloat:point.x], #"y":[NSNumber numberWithFloat:point.y]};
NSArray * horizontal = [NSLayoutConstraint constraintsWithVisualFormat:#"H:|-x-[nodeView]" options:0 metrics:metricDict views:viewDict];
NSArray * vertical = [NSLayoutConstraint constraintsWithVisualFormat:#"V:|-y-[nodeView]" options:0 metrics:metricDict views:viewDict];
[self.gridView addConstraints:horizontal];
[self.gridView addConstraints:vertical];
// Update and layout constraints
[self.gridView layoutIfNeeded];
return nodeView;
}
...and yet, it always appears at its original frame, which is not adjusted for auto layout! If I switch to a plain ordinary UIView and use the exact same layout code it works perfectly, things only go wrong when I add subviews, with or without constraints, to my primary view. It feels like there's something I'm supposed to do to make custom layouts work properly, but I've no idea what it might be.
Anyone got any ideas?
-Ash

Answer 1

Ok, it would seem that there has been a change, and overriding the method for translatesAutoresizingMaskIntoConstraints no longer works as expected; removing that method and setting the property it references fixes at least some of the problems I'm experiencing.