Star Rating Control

MNGStarRating.swift

//
//  MNGStarRating.swift
//  CommonCents
//
//  Created by Tommie N. Carter, Jr., MBA on 11/27/15.
//  Copyright © 2015 MING Technology. All rights reserved.
//

import UIKit

/*
   Usage: On Controller ~>
         @IBOutlet var ratingHeader: MNGStarRating! {
                didSet {
                ratingHeader.ratingDelegate = self
             }
          }

  //within delegate methods: ratingWasChanged 
 self.ratingButton.setTitle(self.starRatingOutlet.starTitle(), forState: UIControlState.Normal)

*/
protocol MNGStarRatingDelegate {
    func ratingWasChanged(value:Float?)
}

class MNGStarRating: UIView {

    //MARK: Outlets
    @IBOutlet var starCollection:[UIButton]!
    
    //MARK: Class Properties
    var ratingDelegate:MNGStarRatingDelegate? = nil
    private var starRating:Float = 0.0
    //MARK: View Lifecycle
    override func awakeFromNib() {
        super.awakeFromNib()
        loadDefaultRatingImages()
    }
    /*
    // Only override drawRect: if you perform custom drawing.
    // An empty implementation adversely affects performance during animation.
    override func drawRect(rect: CGRect) {
        // Drawing code
    }
    */
    
    //MARK: Helper Methods
    
    func loadDefaultRatingImages() {
        for b in starCollection {
            
            switch b.tag {
            case 1:
                b.setBackgroundImage(UIImage(named: "star1"), forState: .Highlighted)
                break
            case 2:
                b.setBackgroundImage(UIImage(named: "star2"), forState: .Highlighted)
                break
            case 3:
                b.setBackgroundImage(UIImage(named: "star3"), forState: .Highlighted)
                break
            case 4:
                b.setBackgroundImage(UIImage(named: "star4"), forState: .Highlighted)
                break
            case 5:
                b.setBackgroundImage(UIImage(named: "star5"), forState: .Highlighted)
                break
            default:
                break
                
            }
        }
    }
    func starTitle() -> String {
        guard self.starRating > 0.0 else {
            return "Transaction Rating"
        }
        let title =  [String](count: Int(self.starRating), repeatedValue: "✭")
        return title.joinWithSeparator("")
    }
    //MARK: Action Methods
    @IBAction func highlightButtonsUpto(button:UIButton) {
        let targetValue = (button.tag)
        let _ = starCollection.map({ $0.highlighted = false })
        
        for b in starCollection {
            if  targetValue > b.tag  {
                b.highlighted = true
            }
        }
        //keeps last button highlighted
        button.cancelTrackingWithEvent(nil)
        button.highlighted = true
        
        starRating = Float(targetValue)
        ratingDelegate?.ratingWasChanged(Float(targetValue))
    }
}