feat: improve quality of thumbnails and performance

src/api-wrappers/HelperExtensions.swift

@@ -199,6 +199,17 @@ extension DispatchQoS {
     }
 }
 
+extension NSImageView {
+    func setSize(_ size: NSSize) {
+        frame.size = size
+        // TODO: NSImageView does some internal magic, and ends up with constraints. We need to add our own to force its size
+        // We can't update .image.size because we share the image between multiple NSImageViews
+        // I wish there was a better way to only set the frame.size
+        addOrUpdateConstraint(widthAnchor, size.width)
+        addOrUpdateConstraint(heightAnchor, size.height)
+    }
+}
+
 extension NSImage {
     // NSImage(named) caches/reuses NSImage objects; we force separate instances of images by using copy()
     static func initCopy(_ name: String) -> NSImage {

src/logic/Window.swift

@@ -7,6 +7,7 @@ class Window {
     var creationOrder = Int.zero
     var title: String!
     var thumbnail: NSImage?
+    var thumbnailFullSize: NSSize?
     var icon: NSImage? { get { application.icon } }
     var shouldShowTheUser = true
     var isTabbed: Bool = false
@@ -98,6 +99,7 @@ class Window {
 
     func refreshThumbnail(_ screenshot: NSImage?) {
         thumbnail = screenshot
+        thumbnailFullSize = screenshot?.size
         if App.app.appIsBeingUsed && shouldShowTheUser {
             if let index = (Windows.list.firstIndex { $0.cgWindowId == cgWindowId }) {
                 let view = ThumbnailsView.recycledViews[index]
@@ -111,9 +113,9 @@ class Window {
         }
     }
 
-    func getPreview() -> NSImage? {
-        if let cgImage = cgWindowId?.screenshot(true) {
-            return NSImage.fromCgImage(cgImage)
+    func getPreview() -> (NSImage, NSSize)? {
+        if let thumbnail = thumbnail, let thumbnailFullSize = thumbnailFullSize {
+            return (thumbnail, thumbnailFullSize)
         }
         return nil
     }

src/logic/Windows.swift

@@ -153,14 +153,14 @@ class Windows {
             App.app.appIsBeingUsed && App.app.thumbnailsPanel.isKeyWindow,
             let window = focusedWindow(),
             let id = window.cgWindowId,
-            let preview = window.getPreview(),
+            let (preview, previewSize) = window.getPreview(),
             let position = window.position,
             let size = window.size
         else {
             App.app.previewPanel.orderOut(nil)
             return
         }
-        App.app.previewPanel.show(id, preview, position, size)
+        App.app.previewPanel.show(id, preview, previewSize, position, size)
     }
 
     static func voiceOverWindow(_ windowIndex: Int = focusedWindowIndex) {

src/ui/App.swift

@@ -252,7 +252,7 @@ class App: AppCenterApplication, NSApplicationDelegate {
 
     func refreshOpenUi(_ windowsToScreenshot: [Window], skipUpdatesBeforeShowing: Bool = false, onlyUpdateScreenshots: Bool = false) {
         if !Appearance.hideThumbnails && !windowsToScreenshot.isEmpty {
-            Windows.refreshThumbnails(windowsToScreenshot, false, onlyUpdateScreenshots)
+            Windows.refreshThumbnails(windowsToScreenshot, true, onlyUpdateScreenshots)
             return
         }
         guard appIsBeingUsed else { return }

src/ui/main-window/PreviewPanel.swift

@@ -25,9 +25,10 @@ class PreviewPanel: NSPanel {
         setAccessibilitySubrole(.unknown)
     }
 
-    func show(_ id: CGWindowID, _ preview: NSImage, _ position: CGPoint, _ size: CGSize) {
+    func show(_ id: CGWindowID, _ preview: NSImage, _ previewSize: NSSize, _ position: CGPoint, _ size: CGSize) {
         if id != currentId  {
             previewView.image = preview
+            previewView.image!.size = previewSize
             var frame = NSRect(origin: position, size: size)
             // Flip Y coordinate from Quartz (0,0 at bottom-left) to Cocoa coordinates (0,0 at top-left)
             // Always use the primary screen as reference since all coordinates are relative to it

src/ui/main-window/ThumbnailView.swift

@@ -159,11 +159,14 @@ class ThumbnailView: FlippedView {
 
     private func setupSharedSubiews() {
         let shadow = ThumbnailView.makeShadow(Appearance.imageShadowColor)
+        thumbnail.imageScaling = .scaleProportionallyUpOrDown
         thumbnail.shadow = shadow
         windowlessIcon.translatesAutoresizingMaskIntoConstraints = false
+        windowlessIcon.imageScaling = .scaleProportionallyUpOrDown
         windowlessIcon.toolTip = ThumbnailView.noOpenWindowToolTip
         windowlessIcon.shadow = shadow
         appIcon.translatesAutoresizingMaskIntoConstraints = false
+        appIcon.imageScaling = .scaleProportionallyUpOrDown
         appIcon.shadow = shadow
         appIcon.setSubviewAbove(dockLabelIcon)
         label.fixHeight()
@@ -340,8 +343,8 @@ class ThumbnailView: FlippedView {
         if appIconChanged || dockLabelChanged {
             setAccessibilityHelp(getAccessibilityHelp(element.application.runningApplication.localizedName, element.dockLabel))
         }
-        if element.isWindowlessApp {
-            windowlessIcon.image = appIcon.image!.copy() as? NSImage
+        if element.isWindowlessApp && windowlessIcon.image != element.icon {
+            windowlessIcon.image = element.icon
         }
         windowControlIcons.forEach { $0.window_ = element }
         showOrHideWindowControls(false)
@@ -353,19 +356,16 @@ class ThumbnailView: FlippedView {
         if Preferences.appearanceStyle == .thumbnails {
             if !thumbnail.isHidden {
                 let thumbnailSize = ThumbnailView.thumbnailSize(thumbnail.image, screen, false)
-                thumbnail.image?.size = thumbnailSize
-                thumbnail.frame.size = thumbnailSize
+                thumbnail.setSize(thumbnailSize)
             }
             if !windowlessIcon.isHidden {
                 let windowlessIconSize = ThumbnailView.thumbnailSize(windowlessIcon.image, screen, true)
-                windowlessIcon.image!.size = windowlessIconSize
-                windowlessIcon.frame.size = windowlessIconSize
+                windowlessIcon.setSize(windowlessIconSize)
             }
         }
         setFrameWidthHeight(screen, newHeight)
         let appIconSize = ThumbnailView.iconSize(screen)
-        appIcon.image?.size = appIconSize
-        appIcon.frame.size = appIconSize
+        appIcon.setSize(appIconSize)
         if Preferences.appearanceStyle == .appIcons {
             vStackView.frame.size = NSSize(width: frame.width, height: appIcon.frame.height + Appearance.edgeInsetsSize * 2)
             hStackView.frame.size = NSSize(width: appIcon.frame.width, height: appIcon.frame.height)