use ImageFormat.loadImageFrom() in GalleryItem, too

deltachat-ios/Model/GalleryItem.swift

@@ -42,36 +42,18 @@ class GalleryItem: ContextMenuItem {
             return
         }
         switch viewtype {
-        case .image:
-            if url.pathExtension == "webp" {
-                loadAsyncSDImageThumbnail(from: url)
-            } else {
-                loadAsyncUIImageThumbnail(from: url)
-            }
+        case .image, .gif:
+            loadImageThumbnail(from: url)
         case .video:
             loadVideoThumbnail(from: url)
-        case .gif:
-            loadAsyncSDImageThumbnail(from: url)
         default:
             safe_fatalError("unsupported viewtype - viewtype \(viewtype) not supported.")
         }
     }
 
-    private func loadAsyncUIImageThumbnail(from url: URL) {
+    private func loadImageThumbnail(from url: URL) {
         DispatchQueue.global(qos: .userInteractive).async {
-            guard let imageData = try? Data(contentsOf: url) else {
-                return
-            }
-            let image = UIImage(data: imageData)
-            DispatchQueue.main.async { [weak self] in
-                    self?.thumbnailImage = image
-            }
-        }
-    }
-
-    private func loadAsyncSDImageThumbnail(from url: URL) {
-        DispatchQueue.global(qos: .userInteractive).async { [weak self] in
-            let image = SDAnimatedImage(contentsOfFile: url.path)
+            let image = ImageFormat.loadImageFrom(url: url)
             DispatchQueue.main.async { [weak self] in
                     self?.thumbnailImage = image
             }