feat: show loading indicator when photo is being loaded

Memola/Canvas/Tool/Core/Tool.swift

@@ -20,6 +20,7 @@ public class Tool: NSObject, ObservableObject {
     @Published var draggedPen: Pen?
     // MARK: - Photo
     @Published var selectedPhotoItem: PhotoItem?
+    @Published var isLoadingPhoto: Bool = false
 
     @Published var selection: ToolSelection = .hand
 
@@ -120,6 +121,7 @@ public class Tool: NSObject, ObservableObject {
     func selectPhoto(_ image: UIImage, for canvasID: NSManagedObjectID) {
         guard let (resizedImage, dimension) = resizePhoto(of: image) else { return }
         let photoItem = bookmarkPhoto(of: resizedImage, in: dimension, with: canvasID)
+        isLoadingPhoto = false
         withAnimation {
             selectedPhotoItem = photoItem
         }

Memola/Features/Memo/Memo/MemoView.swift

@@ -46,7 +46,7 @@ struct MemoView: View {
             .overlay(alignment: .bottomLeading) {
                 zoomControl
             }
-            .disabled(textFieldState)
+            .disabled(textFieldState || tool.isLoadingPhoto)
             .overlay(alignment: .top) {
                 Toolbar(size: size, memo: memo, tool: tool, canvas: canvas, history: history)
             }
@@ -61,6 +61,11 @@ struct MemoView: View {
                     EmptyView()
                 }
             }
+            .overlay {
+                if tool.isLoadingPhoto {
+                    loadingIndicator("Loading photo...")
+                }
+            }
     }
 
     @ViewBuilder

Memola/Features/Memo/Toolbar/Toolbar.swift

@@ -62,6 +62,7 @@ struct Toolbar: View {
         .onChange(of: photosPickerItem) { oldValue, newValue in
             if newValue != nil {
                 Task {
+                    tool.isLoadingPhoto = true
                     let data = try? await newValue?.loadTransferable(type: Data.self)
                     if let data, let image = UIImage(data: data) {
                         tool.selectPhoto(image, for: canvas.canvasID)