Thumbnail performance

Shared/Sources/Document/Documents/ImageSaveService.swift

@@ -9,10 +9,14 @@ import Foundation
 
 class ImageSaveService {
     func load(from path: URL) throws -> Image? {
-        let imageURL = path.appendingPathComponent("screen.png")
+        let imageURL = imagePath(documentURL: path)
         let data = try Data(contentsOf: imageURL)
         return Image(data: data)
     }
+
+    func imagePath(documentURL: URL) -> URL {
+        documentURL.appendingPathComponent("screen.png")
+    }
 }
 
 #if os(iOS)

Shared/Sources/Document/Documents/VODesignDocument+AppKit.swift

@@ -7,6 +7,7 @@ import os
 
 public let vodesign = "vodesign"
 public let uti = "com.akaDuality.vodesign"
+import QuickLookThumbnailing
 
 public class VODesignDocument: Document, VODesignDocumentProtocol {
 
@@ -85,10 +86,35 @@ public class VODesignDocument: Document, VODesignDocumentProtocol {
         return true
     }
 
-    public static func image(from url: URL) -> Image? {
+    public static func image(from url: URL) async -> Image? {
         try? ImageSaveService().load(from: url)
     }
 
+    private var thumbnailCache: Image?
+    public func thumbnail(size: CGSize, scale: CGFloat) async -> Image? {
+        guard let fileURL else {
+            return nil
+        }
+
+        if let thumbnailCache {
+            // TODO: Invalidate cache if other size is requested
+            return thumbnailCache
+        }
+
+        let imagePath = ImageSaveService().imagePath(documentURL: fileURL)
+        let request = QLThumbnailGenerator.Request(
+            fileAt: imagePath,
+            size: size,
+            scale: scale,
+            representationTypes: .thumbnail)
+
+        let previewGenerator = QLThumbnailGenerator()
+        let thumbnail = try? await previewGenerator.generateBestRepresentation(for: request)
+
+        thumbnailCache = thumbnail?.nsImage
+        return thumbnail?.nsImage
+    }
+
     public override class var readableTypes: [String] {
         [uti]
     }
@@ -141,3 +167,11 @@ extension VODesignDocument {
     }
 }
 #endif
+
+import Foundation
+import QuickLookThumbnailing
+public extension URL {
+    var fileName: String {
+        deletingPathExtension().lastPathComponent
+    }
+}

VoiceOver Designer/Features/Sources/Recent/Collection/RecentCollectionViewItem.swift

@@ -18,10 +18,19 @@ class RecentCollectionViewItem: NSCollectionViewItem {
         view = projectCellView
     }
 
-    func configure(image: NSImage?, fileName: String) {
-        projectCellView.thumbnail.image = image
+    func configure(fileName: String) {
         projectCellView.fileNameTextField.stringValue = fileName
         projectCellView.layoutSubtreeIfNeeded()
     }
-
+
+    var image: NSImage? {
+        didSet {
+            projectCellView.thumbnail.image = image
+        }
+    }
+
+    var expectedImageSize: CGSize {
+        CGSize(width: 125,
+               height: 220)
+    }
 }

VoiceOver Designer/Features/Sources/Recent/RecentViewController.swift

@@ -57,6 +57,10 @@ public class RecentViewController: NSViewController {
         let storyboard = NSStoryboard(name: "RecentViewController", bundle: .module)
         return storyboard.instantiateInitialController() as! RecentViewController
     }
+
+    lazy var backingScaleFactor: CGFloat = {
+        view.window?.backingScaleFactor ??  NSScreen.main?.backingScaleFactor ?? 1
+    }()
 }
 
 extension RecentViewController: DragNDropDelegate {
@@ -96,9 +100,18 @@ extension RecentViewController : NSCollectionViewDataSource {
         case .document(let url):
             let item = RecentCollectionViewItem()
             item.configure(
-                image: VODesignDocument.image(from: url),
-                fileName: url.deletingPathExtension().lastPathComponent
+                fileName: url.fileName
             )
+
+            Task {
+                let image = await VODesignDocument(file: url)
+                    .thumbnail(size: item.expectedImageSize,
+                               scale: backingScaleFactor)
+
+                item.image = image
+                // No need to check that item is changed because there is no reuse
+            }
+
             return item
         }
     }

VoiceOver Designer/Features/Tests/RecentTests/ProjectCollectionViewItemTests.swift

@@ -17,25 +17,19 @@ class ProjectCollectionViewItemTests: XCTestCase {
 
     func testConfiguringCollectionViewCell_WithSampleImageAndText() throws {
         let sut = makeSUT()
-        let testImageA11yDescription = "TestA11yDescription"
-        let testImage = NSImage(systemSymbolName: "plus", accessibilityDescription: testImageA11yDescription)
         let fileName = "TestFileName"
 
-        sut.configure(image: testImage, fileName: fileName)
+        sut.configure(fileName: fileName)
 
         XCTAssertEqual(sut.projectCellView.fileNameTextField.stringValue, fileName)
-        XCTAssertEqual(sut.projectCellView.thumbnail.image, testImage)
-        XCTAssertEqual(sut.projectCellView.thumbnail.image?.accessibilityDescription, testImageA11yDescription)
     }
 
     func testConfiguringCollectionViewCell_WithNilImageAndText() throws {
         let sut = makeSUT()
         let fileName = "TestFileName"
 
-        sut.configure(image: nil, fileName: fileName)
+        sut.configure(fileName: fileName)
 
         XCTAssertEqual(sut.projectCellView.fileNameTextField.stringValue, fileName)
-        XCTAssertNil(sut.projectCellView.thumbnail.image)
     }
-
 }