A utility category for utilizing UIKit Auto Layout features efficiently.

UIView+ConstraintsUtil.h

//
//  UIView+ConstraintsUtil.h
//
//  Created by numata on 2014/01/02.
//  Copyright (c) 2014 Sazameki and Satoshi Numata, Ph.D. All rights reserved.
//

@import UIKit;


@interface UIView (ConstraintsUtil)

- (NSLayoutConstraint *)addConstraintToAlignCenterHolizontally;
- (NSLayoutConstraint *)addConstraintToAlignCenterVertically;

- (NSLayoutConstraint *)addConstraintToFitToTopEdge;
- (NSLayoutConstraint *)addConstraintToFitToLeftEdge;
- (NSLayoutConstraint *)addConstraintToFitToRightEdge;
- (NSLayoutConstraint *)addConstraintToFitToBottomEdge;

- (NSLayoutConstraint *)addConstraintToFitToTopEdgeWithPadding:(CGFloat)padding;
- (NSLayoutConstraint *)addConstraintToFitToLeftEdgeWithPadding:(CGFloat)padding;
- (NSLayoutConstraint *)addConstraintToFitToRightEdgeWithPadding:(CGFloat)padding;
- (NSLayoutConstraint *)addConstraintToFitToBottomEdgeWithPadding:(CGFloat)padding;

- (NSLayoutConstraint *)addConstraintToFixWidth;
- (NSLayoutConstraint *)addConstraintToFixHeight;

@end

UIView+ConstraintsUtil.m

//
//  UIView+ConstraintsUtil.m
//
//  Created by numata on 2014/01/02.
//  Copyright (c) 2014 Sazameki and Satoshi Numata, Ph.D. All rights reserved.
//

#import "UIView+ConstraintsUtil.h"


@implementation UIView (ConstraintsUtil)

- (NSLayoutConstraint *)addConstraintToSuperviewWithAttribute:(NSLayoutAttribute)attribute constant:(CGFloat)constant
{
    self.translatesAutoresizingMaskIntoConstraints = NO;
    
    NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:self
                                                                  attribute:attribute
                                                                  relatedBy:NSLayoutRelationEqual
                                                                     toItem:self.superview
                                                                  attribute:attribute
                                                                 multiplier:1.0
                                                                   constant:constant];
    [self.superview addConstraint:constraint];
    
    return constraint;
}

- (NSLayoutConstraint *)addConstraintToSuperviewWithAttribute:(NSLayoutAttribute)attribute
{
    return [self addConstraintToSuperviewWithAttribute:attribute constant:0.0];
}

- (NSLayoutConstraint *)addConstraintWithAttribute:(NSLayoutAttribute)attribute constant:(CGFloat)constant
{
    self.translatesAutoresizingMaskIntoConstraints = NO;
    
    NSLayoutConstraint *constraint = [NSLayoutConstraint constraintWithItem:self
                                                                  attribute:attribute
                                                                  relatedBy:NSLayoutRelationEqual
                                                                     toItem:nil
                                                                  attribute:0
                                                                 multiplier:1.0
                                                                   constant:constant];
    [self addConstraint:constraint];
    
    return constraint;
}

- (NSLayoutConstraint *)addConstraintWithAttribute:(NSLayoutAttribute)attribute
{
    return [self addConstraintWithAttribute:attribute constant:0.0];
}

- (NSLayoutConstraint *)addConstraintToAlignCenterHolizontally
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeCenterX];
}

- (NSLayoutConstraint *)addConstraintToAlignCenterVertically
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeCenterY];
}

- (NSLayoutConstraint *)addConstraintToFitToTopEdge
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeTop];
}

- (NSLayoutConstraint *)addConstraintToFitToLeftEdge
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeLeading];
}

- (NSLayoutConstraint *)addConstraintToFitToRightEdge
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeTrailing];
}

- (NSLayoutConstraint *)addConstraintToFitToBottomEdge
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeBottom];
}

- (NSLayoutConstraint *)addConstraintToFitToTopEdgeWithPadding:(CGFloat)padding
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeTop constant:padding];
}

- (NSLayoutConstraint *)addConstraintToFitToLeftEdgeWithPadding:(CGFloat)padding
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeLeading constant:padding];
}

- (NSLayoutConstraint *)addConstraintToFitToRightEdgeWithPadding:(CGFloat)padding
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeTrailing constant:-padding];
}

- (NSLayoutConstraint *)addConstraintToFitToBottomEdgeWithPadding:(CGFloat)padding
{
    return [self addConstraintToSuperviewWithAttribute:NSLayoutAttributeBottom constant:-padding];
}

- (NSLayoutConstraint *)addConstraintToFixWidth
{
    return [self addConstraintWithAttribute:NSLayoutAttributeWidth constant:self.frame.size.width];
}

- (NSLayoutConstraint *)addConstraintToFixHeight
{
    return [self addConstraintWithAttribute:NSLayoutAttributeHeight constant:self.frame.size.height];
}

@end