OptionalなどSwiftとObjective-Cの違いを意識してPhotos Frameworkを使う：iPhone 6／6 Plusアプリ開発入門（4）（3/3 ページ）

private func prepareAnnotations() {
    let fetchResult = PHAsset.fetchAssetsWithMediaType(PHAssetMediaType.Image, options: nil)
    fetchResult?.enumerateObjectsUsingBlock ({result, index, stop in
        if let asset = result as? PHAsset {
            if let location = asset.location {
                let annotation = MKPointAnnotation()
                annotation.coordinate = location.coordinate
                self.mapView.addAnnotation(annotation)
            }
        }
    })
}

func enumerateObjectsUsingBlock(block: ((AnyObject!, Int, UnsafeMutablePointer<ObjCBool>) -> Void)!)

fetchResult?.enumerateObjectsUsingBlock ({result, index, stop in           
    if let asset = result as? PHAsset {
        // PHAsset型のオブジェクトが取り出せた場合の処理
    }
})

fetchResult?.enumerateObjectsUsingBlock ({result, index, stop in
    if let asset = result as? PHAsset {
        if let location = asset.location {
            // CLLocation型のオブジェクトが取り出せた場合の処理
            // 注釈オブジェクトを作成
            let annotation = MKPointAnnotation()
            annotation.coordinate = location.coordinate
            // MapViewへ追加
            self.mapView.addAnnotation(annotation)
        }
    }
})

import UIKit
import MapKit
import Photos
 
class ViewController: UIViewController {
    @IBOutlet weak var mapView: MKMapView!
 
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        self.prepareMapView()
        self.checkAuthorizationStatus()
    }
 
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    
    private func prepareMapView() {
        self.mapView.rotateEnabled = false
        self.mapView.pitchEnabled = false
        
        let centerCoordinate = CLLocationCoordinate2D(latitude: 35.681382, longitude: 139.766084)
        let initialSpan = MKCoordinateSpan(latitudeDelta: 0.4, longitudeDelta: 0.4)
        let initialRegion = MKCoordinateRegion(center: centerCoordinate, span: initialSpan)
        self.mapView.setRegion(initialRegion, animated: true)
    }
    
    private func checkAuthorizationStatus() {
        let status = PHPhotoLibrary.authorizationStatus()
        
        switch status {
        case .Authorized:
            self.prepareAnnotations()
        default:
            PHPhotoLibrary.requestAuthorization{ status in
                if status == .Authorized {
                    self.prepareAnnotations()
                }
            }
        }
    }
    
    private func prepareAnnotations() {
        let fetchResult = PHAsset.fetchAssetsWithMediaType(PHAssetMediaType.Image, options: nil)
        fetchResult?.enumerateObjectsUsingBlock ({result, index, stop in
            
            if let asset = result as? PHAsset {
                if let location = asset.location {
                    let annotation = MKPointAnnotation()
                    annotation.coordinate = location.coordinate
                    self.mapView.addAnnotation(annotation)
                }
            }
        })
    }
}