Add Photosphere metadata support

Source/Metadata.swift

@@ -0,0 +1,194 @@
+//
+//  Metadata.swift
+//  Pods
+//
+//  Created by BOON CHEW on 5/2/17.
+//
+//
+
+import Foundation
+import PromiseKit
+
+public struct PhotoSphereMetadata {
+    private let elements: [PhotoSphereTag: Any]
+
+    init(elements: [PhotoSphereTag: Any]) {
+        self.elements = elements
+    }
+
+    func isEquirectangular() -> Bool {
+        if let projectionType = self.elements[.projectionType] {
+            return (projectionType as String) == "equirectangular"
+        }
+    }
+
+    func is360() -> Bool {
+        return isEquirectangular()
+    }
+}
+
+public enum PhotoSphereTag: String {
+    case captureSoftware = "GPano:CaptureSoftware"
+    case croppedAreaImageWidthPixels = "GPano:CroppedAreaImageWidthPixels"
+    case croppedAreaImageHeightPixels = "GPano:CroppedAreaImageHeightPixels"
+    case croppedAreaLeftPixels = "GPano:CroppedAreaLeftPixels"
+    case croppedAreaTopPixels = "GPano:CroppedAreaTopPixels"
+    case exposureLockUsed = "GPano:ExposureLockUsed"
+    case firstPhotoDate = "GPano:FirstPhotoDate"
+    case fullPanoWidthPixels = "GPano:FullPanoWidthPixels"
+    case fullPanoHeightPixels = "GPano:FullPanoHeightPixels"
+    case initialCameraDolly = "GPano:InitialCameraDolly"
+    case initialHorizontalFOVDegrees = "GPano:InitialHorizontalFOVDegrees"
+    case initialViewHeadingDegrees = "GPano:InitialViewHeadingDegrees"
+    case initialViewPitchDegrees = "GPano:InitialViewPitchDegrees"
+    case initialViewRollDegrees = "GPano:InitialViewRollDegrees"
+    case lastPhotoDate = "GPano:LastPhotoDate"
+    case poseHeadingDegrees = "GPano:PoseHeadingDegrees"
+    case posePitchDegrees = "GPano:PosePitchDegrees"
+    case poseRollDegrees = "GPano:PoseRollDegrees"
+    case projectionType = "GPano:ProjectionType"
+    case sourcePhotosCount = "GPano:SourcePhotosCount"
+    case stitchingSoftware = "GPano:StitchingSoftware"
+    case usePanoramaViewer = "GPano:UsePanoramaViewer"
+}
+
+class PhotoSphereMetadataParser: NSObject {
+    private var metadata: Data
+    private var parser: XMLParser?
+    private static let xmpMetaStart = "<x:xmpmeta".data(using: .ascii)!
+    private static let xmpMetaEnd   = "</x:xmpmeta>".data(using: .ascii)!
+
+    fileprivate var elements: [PhotoSphereTag: Any]?
+    fileprivate var element: PhotoSphereTag?
+    fileprivate var elementHandler: ((String) -> Void)?
+
+    fileprivate var fulfill: (([PhotoSphereTag: Any]) -> Void)!
+    fileprivate var reject: ((Error) -> Void)!
+
+    override init() {
+        metadata = Data()
+        super.init()
+    }
+
+    func parse(contentsOf url: URL) -> Promise<[PhotoSphereTag: Any]> {
+        let data = try? Data(contentsOf: url)
+        return self.parse(data: data)
+    }
+
+    func parse(data: Data?) -> Promise<[PhotoSphereTag: Any]> {
+        guard let data = data else {
+            return Promise { fulfill, reject in
+                reject(OSCKit.SDKError.unableToParseMetadata)
+            }
+        }
+
+        let (promise, fulfill, reject) = Promise<[PhotoSphereTag: Any]>.pending()
+
+        self.fulfill = fulfill
+        self.reject = reject
+
+        if let startRange = data.range(of: PhotoSphereMetadataParser.xmpMetaStart), let endRange = data.range(of: PhotoSphereMetadataParser.xmpMetaEnd, in: Range(uncheckedBounds: (startRange.upperBound, data.count))) {
+            let range = Range(uncheckedBounds: (startRange.lowerBound, endRange.upperBound))
+            metadata = data.subdata(in: range)
+        }
+
+        parser = XMLParser(data: metadata)
+        parser?.delegate = self
+
+        return promise
+    }
+}
+
+extension PhotoSphereMetadataParser: XMLParserDelegate {
+    func parserDidStartDocument(_ parser: XMLParser) {
+        (elements, element, elementHandler) = ([:], nil, nil)
+    }
+
+    func parserDidEndDocument(_ parser: XMLParser) {
+        self.fulfill(elements!)
+    }
+
+    func parser(_ parser: XMLParser, parseErrorOccurred parseError: Error) {
+        self.reject(OSCKit.SDKError.unableToParseMetadata)
+    }
+
+    func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
+
+        element = PhotoSphereTag(rawValue: elementName)
+        if let element = element {
+            switch element {
+            // Boolean
+            case .usePanoramaViewer: fallthrough
+            case .exposureLockUsed:
+                elementHandler = { self.elements?[element] = ($0 == "True") }
+
+            // String
+            case .captureSoftware: fallthrough
+            case .stitchingSoftware: fallthrough
+            case .projectionType:
+                elementHandler = { self.elements?[element] = $0 }
+
+            // Real
+            case .poseHeadingDegrees: fallthrough
+            case .posePitchDegrees: fallthrough
+            case .poseRollDegrees: fallthrough
+            case .initialHorizontalFOVDegrees: fallthrough
+            case .initialCameraDolly:
+                elementHandler = { self.elements?[element] = Double($0) ?? 0.0 }
+
+            // Integer
+            case .initialViewHeadingDegrees: fallthrough
+            case .initialViewPitchDegrees: fallthrough
+            case .initialViewRollDegrees: fallthrough
+            case .sourcePhotosCount:fallthrough
+            case .croppedAreaImageWidthPixels:fallthrough
+            case .croppedAreaImageHeightPixels: fallthrough
+            case .fullPanoWidthPixels: fallthrough
+            case .fullPanoHeightPixels: fallthrough
+            case .croppedAreaLeftPixels: fallthrough
+            case .croppedAreaTopPixels:
+                elementHandler = { self.elements?[element] = Int($0) ?? 0 }
+
+            // Date
+            case .firstPhotoDate: fallthrough
+            case .lastPhotoDate:
+                elementHandler = { string in
+                    let formatter = DateFormatter()
+                    formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
+                    let date = formatter.date(from: string)
+                    self.elements?[element] = date ?? string
+                }
+            }
+        }
+    }
+
+    func parser(_ parser: XMLParser, foundCharacters string: String) {
+        if let handler = elementHandler {
+            handler(string)
+
+            element = nil
+            elementHandler = nil
+        }
+    }
+}
+
+extension OSCKit {
+    public func metadata(of url: URL) -> Promise<[PhotoSphereTag: Any]> {
+        return PhotoSphereMetadataParser().parse(contentsOf: url)
+    }
+
+    public func metadata(of image: UIImage) -> Promise<[PhotoSphereTag: Any]> {
+        let data = UIImageJPEGRepresentation(image, 1.0)
+        return metadata(of: data!)
+    }
+
+    public func metadata(of data: Data) -> Promise<[PhotoSphereTag: Any]> {
+        return PhotoSphereMetadataParser().parse(data: data)
+    }
+}
+
+//OSCKit.shared.metadata(of: "").then { metadata in
+//    if metadata.isPanorama {
+//
+//    }
+//}

Source/OSCKit.swift

@@ -18,6 +18,7 @@ public class OSCKit {
         case unableToFindCacheFolder
         case unableToFindVideo
         case unableToCreateVideoCacheKey
+        case unableToParseMetadata
     }
 
     private init() { }