Show unknown attachments

Closes #47

Tusker/Views/Attachments/AttachmentView.swift

@@ -107,10 +107,6 @@ class AttachmentView: GIFImageView {
     }
     
     func loadAttachment() {
-        guard AttachmentsContainerView.supportedAttachmentTypes.contains(attachment.kind) else {
-            fatalError("invalid attachment type")
-        }
-        
         if let hash = attachment.blurHash {
             AttachmentView.queue.async { [weak self] in
                 guard let self = self else { return }
@@ -142,8 +138,8 @@ class AttachmentView: GIFImageView {
             loadAudio()
         case .gifv:
             loadGifv()
-        default:
-            fatalError("invalid attachment type")
+        case .unknown:
+            createUnknownLabel()
         }
     }
     
@@ -301,6 +297,25 @@ class AttachmentView: GIFImageView {
         ])
     }
     
+    func createUnknownLabel() {
+        backgroundColor = .appSecondaryBackground
+        let label = UILabel()
+        label.text = "Unknown Attachment Type"
+        label.numberOfLines = 0
+        label.textAlignment = .center
+        label.textColor = .secondaryLabel
+        label.font = .preferredFont(forTextStyle: .body)
+        label.adjustsFontForContentSizeCategory = true
+        label.translatesAutoresizingMaskIntoConstraints = false
+        addSubview(label)
+        NSLayoutConstraint.activate([
+            label.leadingAnchor.constraint(equalTo: leadingAnchor),
+            label.trailingAnchor.constraint(equalTo: trailingAnchor),
+            label.topAnchor.constraint(equalTo: topAnchor),
+            label.bottomAnchor.constraint(equalTo: bottomAnchor),
+        ])
+    }
+    
     @MainActor
     private func displayImage() {
         isGrayscale = Preferences.shared.grayscaleImages

Tusker/Views/Attachments/AttachmentsContainerView.swift

@@ -11,8 +11,6 @@ import Pachyderm
 
 class AttachmentsContainerView: UIView {
     
-    static let supportedAttachmentTypes = [Attachment.Kind.image, .video, .audio, .gifv]
-    
     weak var delegate: AttachmentViewDelegate?
     
     private var attachmentTokens: [AttachmentToken] = []
@@ -70,7 +68,6 @@ class AttachmentsContainerView: UIView {
     // MARK: - User Interaface
     
     func updateUI(attachments: [Attachment]) {
-        let attachments = attachments.filter { AttachmentsContainerView.supportedAttachmentTypes.contains($0.kind) }
         let newTokens = attachments.map { AttachmentToken(attachment: $0) }
         
         guard self.attachmentTokens != newTokens else {