fixed blinking on image load

Author: gitbrent

MacImageManager/MacImageManager/Views/PaneImageViewer.swift

@@ -12,22 +12,43 @@ struct PaneImageViewer: View {
     @State private var loadedImage: NSImage?
     @State private var currentLoadingURL: URL?
     @State private var loadingTask: Task<Void, Never>?
+    @State private var isLoading: Bool = false
 
     var body: some View {
         Group {
             if selectedImage != nil {
-                if let loadedImage = loadedImage, currentLoadingURL == selectedImage {
-                    ScrollView([.horizontal, .vertical]) {
-                        Image(nsImage: loadedImage)
-                            .resizable()
-                            .aspectRatio(contentMode: .fit) // These 2 lines: fit image to view
-                            .containerRelativeFrame([.horizontal, .vertical]) // These 2 lines: fit image to view
-                    }
-                    .background(Color.black)
-                } else {
-                    ProgressView("Loading...")
-                        .frame(maxWidth: .infinity, maxHeight: .infinity)
+                ZStack {
+                    // Show the loaded image (either current or previous)
+                    if let loadedImage = loadedImage {
+                        ScrollView([.horizontal, .vertical]) {
+                            Image(nsImage: loadedImage)
+                                .resizable()
+                                .aspectRatio(contentMode: .fit) // These 2 lines: fit image to view
+                                .containerRelativeFrame([.horizontal, .vertical]) // These 2 lines: fit image to view
+                        }
                         .background(Color.black)
+                    } else {
+                        // Only show black background with spinner if no image has been loaded yet
+                        ProgressView("Loading...")
+                            .frame(maxWidth: .infinity, maxHeight: .infinity)
+                            .background(Color.black)
+                    }
+
+                    // Show loading indicator in corner when loading a new image but previous image exists
+                    if isLoading && loadedImage != nil {
+                        VStack {
+                            HStack {
+                                Spacer()
+                                ProgressView()
+                                    .scaleEffect(0.8)
+                                    .padding()
+                                    .background(Color.black.opacity(0.6))
+                                    .clipShape(RoundedRectangle(cornerRadius: 6))
+                                    .padding()
+                            }
+                            Spacer()
+                        }
+                    }
                 }
             } else {
                 VStack {
@@ -58,21 +79,26 @@ struct PaneImageViewer: View {
         guard let url = url else {
             loadedImage = nil
             currentLoadingURL = nil
+            isLoading = false
             return
         }
 
         // Don't reload if it's the exact same URL and we already have the image loaded for it
         if currentLoadingURL == url && loadedImage != nil {
+            isLoading = false
             return
         }
 
-        // Set the new loading URL and clear image if switching URLs
+        // Set the new loading URL but keep the previous image
         let previousURL = currentLoadingURL
         currentLoadingURL = url
 
-        // Clear the loaded image if we're switching to a different URL
-        if previousURL != url {
-            loadedImage = nil
+        // Only clear the loaded image if we don't have any image yet
+        if loadedImage == nil {
+            isLoading = true
+        } else {
+            // We have a previous image, show loading indicator but keep the image
+            isLoading = true
         }
 
         loadingTask = Task {
@@ -88,6 +114,7 @@ struct PaneImageViewer: View {
             if !Task.isCancelled && currentLoadingURL == url {
                 await MainActor.run {
                     self.loadedImage = image
+                    self.isLoading = false
                 }
             }
         }