BradB132

@IBOutlet weak var constraint1: NSLayoutConstraint!
@IBOutlet weak var constraint2: NSLayoutConstraint!

@IBAction func slider1Changed(sender: AnyObject) {	
    constraint1.constant = CGFloat((sender as UISlider).value)
}

@IBAction func slider2Changed(sender: AnyObject) {	
    constraint2.constant = CGFloat((sender as UISlider).value)
}

BradB132

@IBOutlet weak var removableView: UIView!

@IBAction func removeView(sender: AnyObject) {

    removableView.removeFromSuperview()
}

BradB132

@IBOutlet weak var constraint1: NSLayoutConstraint!

@IBAction func slider1Changed(sender: AnyObject) {
    constraint1.constant = CGFloat((sender as UISlider).value)
}

BradB132

@IBOutlet weak var constraint1: NSLayoutConstraint!
@IBOutlet weak var constraint2: NSLayoutConstraint!

@IBAction func animateViews(sender: AnyObject) {
    constraint1.constant = CGFloat(arc4random_uniform(200))
    constraint2.constant = CGFloat(arc4random_uniform(200))

    UIView.animateWithDuration(0.5, animations: {
        self.view.setNeedsUpdateConstraints()
        self.view.layoutIfNeeded()

BradB132

-(void)prepareLayout
{
    //don't forget to call super here
    [super prepareLayout];
 
    /* pre-calculate and cache whatever you need here */
 
    //maybe you would want to loop over each cell like this?
    for(NSUInteger i = 0; i < [self.collectionView numberOfSections]; i++)
    {

BradB132

- (CGSize)collectionViewContentSize
{
    return CGSizeMake(/* calculate your width */,
                      /* calculate your height */);
}

BradB132

-(NSArray*)layoutAttributesForElementsInRect:(CGRect)rect
{
    NSMutableArray* elementsInRect = [NSMutableArray array];

    //iterate over all cells in this collection
    for(NSUInteger i = 0; i < [self.collectionView numberOfSections]; i++)
    {
        for(NSUInteger j = 0; j < [self.collectionView numberOfItemsInSection:i]; j++)
        {
            //this is the cell at row j in section i

BradB132

-(UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewLayoutAttributes* attr = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
 
    CGRect cellFrame = CGRectMake(/* calculate your origin x */,
                                  /* calculate your origin y */,
                                  /* calculate your width */,
                                  /* calculate your height */);
    attr.frame = cellFrame;
 

BradB132

class MyClass {
    lazy var myLazyProperty = ExpensiveObject()
}

BradB132

func exampleFunc(intArg:Int) {
    // ...
}
exampleFunc(5) //just pass the expression, no name needed