CollectionViewController.swift

//
//  CollectionViewController.swift
//  StackControllerExample
//
//  Created by Blaine Fahey on 3/20/16.
//  Copyright © 2016 Blaine Fahey. All rights reserved.
//

import UIKit

class CollectionViewController: UICollectionViewController {
    
    private func updateContentSize() {
        preferredContentSize = collectionView!.contentSize
    }
    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)

        updateContentSize()
    }
    
    override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
        coordinator.animateAlongsideTransition(nil) { [unowned self] context in
            self.updateContentSize()
        }
    }
    
    override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1
    }
    
    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return HelloImCallie.images.count
    }
    
    override func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
        let header = collectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: "Header", forIndexPath: indexPath)
        return header
    }
    
    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("Cell", forIndexPath: indexPath) as! CollectionViewCell
        
        cell.label.text = "Corgi #\(indexPath.row+1)"
        
        if let url = NSURL(string: HelloImCallie.images[indexPath.row]) {
            cell.imageView.imageFromURL(url, completion: nil)
        }
        
        return cell
    }
    
    override func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        HelloImCallie.openInSafari()
    }
}

class CollectionViewCell: UICollectionViewCell {
    @IBOutlet var label: UILabel!
    @IBOutlet var imageView: UIImageView!
    
    override func awakeFromNib() {
        super.awakeFromNib()
        
        imageView.layer.cornerRadius = 15.0
    }
    
    override var highlighted: Bool {
        didSet {
            imageView.alpha = highlighted ? 0.7 : 1.0;
        }
    }
}