Fix GIFs dragged from Finder posting as static images

Closes #239

Tusker/Models/CompositionAttachment.swift

@@ -56,6 +56,7 @@ private let imageType = UTType.image.identifier
 private let mp4Type = UTType.mpeg4Movie.identifier
 private let quickTimeType = UTType.quickTimeMovie.identifier
 private let dataType = UTType.data.identifier
+private let gifType = UTType.gif.identifier
 
 extension CompositionAttachment: NSItemProviderWriting {
     static var writableTypeIdentifiersForItemProvider: [String] {
@@ -95,20 +96,22 @@ extension CompositionAttachment: NSItemProviderReading {
         [typeIdentifier] + UIImage.readableTypeIdentifiersForItemProvider + [mp4Type, quickTimeType] + NSURL.readableTypeIdentifiersForItemProvider
     }
     
-    static func object(withItemProviderData data: Data, typeIdentifier: String) throws -> Self {
+    static func object(withItemProviderData data: Data, typeIdentifier: String) throws -> CompositionAttachment {
         if typeIdentifier == CompositionAttachment.typeIdentifier {
-            return try PropertyListDecoder().decode(Self.self, from: data)
+            return try PropertyListDecoder().decode(CompositionAttachment.self, from: data)
+        } else if typeIdentifier == gifType {
+            return CompositionAttachment(data: .gif(data))
         } else if UIImage.readableTypeIdentifiersForItemProvider.contains(typeIdentifier), let image = try? UIImage.object(withItemProviderData: data, typeIdentifier: typeIdentifier) {
-            return CompositionAttachment(data: .image(image)) as! Self
+            return CompositionAttachment(data: .image(image))
         } else if let type = UTType(typeIdentifier), type == .mpeg4Movie || type == .quickTimeMovie {
             let temporaryDirectoryURL = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true)
             let temporaryFileName = ProcessInfo().globallyUniqueString
             let fileExt = type.preferredFilenameExtension!
             let temporaryFileURL = temporaryDirectoryURL.appendingPathComponent(temporaryFileName).appendingPathExtension(fileExt)
             try data.write(to: temporaryFileURL)
-            return CompositionAttachment(data: .video(temporaryFileURL)) as! Self
+            return CompositionAttachment(data: .video(temporaryFileURL))
         } else if NSURL.readableTypeIdentifiersForItemProvider.contains(typeIdentifier), let url = try? NSURL.object(withItemProviderData: data, typeIdentifier: typeIdentifier) as URL {
-            return CompositionAttachment(data: .video(url)) as! Self
+            return CompositionAttachment(data: .video(url))
         } else {
             throw ItemProviderError.incompatibleTypeIdentifier
         }

Tusker/Models/CompositionAttachmentData.swift

@@ -16,6 +16,7 @@ enum CompositionAttachmentData {
     case image(UIImage)
     case video(URL)
     case drawing(PKDrawing)
+    case gif(Data)
     
     var type: AttachmentType {
         switch self {
@@ -27,6 +28,8 @@ enum CompositionAttachmentData {
             return .video
         case .drawing(_):
             return .image
+        case .gif(_):
+            return .image
         }
     }
     
@@ -119,6 +122,8 @@ enum CompositionAttachmentData {
         case let .drawing(drawing):
             let image = drawing.imageInLightMode(from: drawing.bounds, scale: 1)
             completion(.success((image.pngData()!, .png)))
+        case let .gif(data):
+            completion(.success((data, .gif)))
         }
     }
     
@@ -191,6 +196,8 @@ extension CompositionAttachmentData: Codable {
             try container.encode("drawing", forKey: .type)
             let drawingData = drawing.dataRepresentation()
             try container.encode(drawingData, forKey: .drawing)
+        case .gif(_):
+            throw EncodingError.invalidValue(self, EncodingError.Context(codingPath: [], debugDescription: "gif CompositionAttachments cannot be encoded"))
         }
     }
     
@@ -214,7 +221,7 @@ extension CompositionAttachmentData: Codable {
             let drawing = try PKDrawing(data: drawingData)
             self = .drawing(drawing)
         default:
-            throw DecodingError.dataCorruptedError(forKey: .type, in: container, debugDescription: "CompositionAttachment type must be one of 'image' or 'asset'")
+            throw DecodingError.dataCorruptedError(forKey: .type, in: container, debugDescription: "CompositionAttachment type must be one of image, asset, or drawing")
         }
     }
     

Tusker/Screens/Asset Picker/AssetPreviewViewController.swift

@@ -13,18 +13,14 @@ import AVKit
 
 class AssetPreviewViewController: UIViewController {
 
-    let attachment: CompositionAttachmentData
+    let asset: PHAsset
     
-    init(attachment: CompositionAttachmentData) {
+    init(asset: PHAsset) {
-        self.attachment = attachment
+        self.asset = asset
         
         super.init(nibName: nil, bundle: nil)
     }
     
-    convenience init(asset: PHAsset) {
-        self.init(attachment: .asset(asset))
-    }
-    
     required init?(coder: NSCoder) {
         fatalError("init(coder:) has not been implemented")
     }
@@ -34,12 +30,6 @@ class AssetPreviewViewController: UIViewController {
         
         view.backgroundColor = .black
 
-        switch attachment {
-        case let .image(image):
-            showImage(image)
-        case let .video(url):
-            showVideo(asset: AVURLAsset(url: url))
-        case let .asset(asset):
         switch asset.mediaType {
         case .image:
             if asset.mediaSubtypes.contains(.photoLive) {
@@ -52,10 +42,6 @@ class AssetPreviewViewController: UIViewController {
         default:
             fatalError("asset mediaType must be image or video")
         }
-        case let .drawing(drawing):
-            let image = drawing.imageInLightMode(from: drawing.bounds)
-            showImage(image)
-        }
     }
     
     func showImage(_ image: UIImage) {

Tusker/Screens/Compose/ComposeAttachmentImage.swift

@@ -69,6 +69,10 @@ struct ComposeAttachmentImage: View {
             image = drawing.imageInLightMode(from: drawing.bounds)
             imageContentMode = .fit
             imageBackgroundColor = .white
+        case let .gif(data):
+            if let image = UIImage(data: data) {
+                self.image = image
+            }
         }
     }
 }