perf: improve mouse hover algo and core-animation side

src/ui/generic-components/LightImageView.swift

@@ -26,6 +26,7 @@ class LightImageView: NSView {
             "position": NSNull(),
             "contentsScale": NSNull()
         ]
+        layerContentsRedrawPolicy = .never
     }
 
     func updateWithResizedCopy(_ image: CGImage?, _ size: NSSize) {
@@ -38,7 +39,9 @@ class LightImageView: NSView {
             layer!.contents = image
             layer!.contentsScale = scaleFactor
         }
-        frame.size = size
+        if frame.size != size {
+            frame.size = size
+        }
     }
 
     /// this schedules the image update for the next cycle

src/ui/main-window/ThumbnailView.swift

@@ -143,21 +143,27 @@ class ThumbnailView: FlippedView {
     }
 
     func showOrHideWindowControls(_ shouldShowWindowControls: Bool) {
+        guard Preferences.appearanceStyle == .thumbnails else { return }
         let shouldShow = shouldShowWindowControls && !Preferences.hideColoredCircles && !Appearance.hideThumbnails
-        if Preferences.appearanceStyle == .thumbnails {
-            isShowingWindowControls = shouldShow
-            for icon in windowControlIcons {
-                icon.isHidden = !shouldShow
-                    || (icon.type == .quit && !(window_?.application.canBeQuit() ?? true))
-                    || (icon.type == .close && !(window_?.canBeClosed() ?? true))
-                    || ((icon.type == .miniaturize || icon.type == .fullscreen) && !(window_?.canBeMinDeminOrFullscreened() ?? true))
-                // Force the icons to redraw; otherwise after clicking the fullscreen button,
-                // it will still appear to be in fullscreen mode.
-                icon.display()
+        guard isShowingWindowControls != shouldShow else { return }
+        isShowingWindowControls = shouldShow
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        for icon in windowControlIcons {
+            let shouldHide = !shouldShow
+                || (icon.type == .quit && !(window_?.application.canBeQuit() ?? true))
+                || (icon.type == .close && !(window_?.canBeClosed() ?? true))
+                || ((icon.type == .miniaturize || icon.type == .fullscreen) && !(window_?.canBeMinDeminOrFullscreened() ?? true))
+
+            if icon.isHidden != shouldHide {
+                icon.isHidden = shouldHide
+                icon.needsDisplay = true
             }
         }
+        CATransaction.commit()
     }
 
+
     func updateDockLabelIcon(_ dockLabel: String?) {
         assignIfDifferent(&dockLabelIcon.isHidden, dockLabel == nil || Preferences.hideAppBadges || Appearance.iconSize == 0)
         if !dockLabelIcon.isHidden, let dockLabel {

src/ui/main-window/ThumbnailsView.swift

@@ -277,33 +277,38 @@ class ScrollView: NSScrollView {
         }
     }
 
+    override func mouseExited(with event: NSEvent) {
+        previousTarget = nil
+        resetHoveredWindow()
+    }
+
     override func mouseMoved(with event: NSEvent) {
-        // disable mouse hover during scrolling as it creates jank during elastic bounces at the start/end of the scrollview
-        // also disable it when ScrollwheelEvents is enabled, as it indicates that a multi-finder gesture is in progress
-        if isCurrentlyScrolling || ScrollwheelEvents.shouldBeEnabled { return }
-        if let hit = hitTest(App.app.thumbnailsPanel.mouseLocationOutsideOfEventStream) {
-            var target: NSView? = hit
-            while !(target is ThumbnailView) && target != nil {
-                target = target!.superview
-            }
-            if let target = target as? ThumbnailView {
-                if previousTarget != target {
-                    previousTarget?.showOrHideWindowControls(false)
-                    previousTarget = target
-                }
-                target.mouseMoved()
-            } else {
-                if !checkIfWithinInterPadding() {
-                    resetHoveredWindow()
-                }
-            }
+        guard let documentView, !isCurrentlyScrolling && !ScrollwheelEvents.shouldBeEnabled else { return }
+        let location = documentView.convert(App.app.thumbnailsPanel.mouseLocationOutsideOfEventStream, from: nil)
+        let newTarget = findTarget(location)
+        guard newTarget !== previousTarget else { return }
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        if let newTarget {
+            previousTarget?.showOrHideWindowControls(false)
+            newTarget.mouseMoved()
         } else {
             resetHoveredWindow()
         }
+        previousTarget = newTarget
+        CATransaction.commit()
     }
 
-    override func mouseExited(with event: NSEvent) {
-        resetHoveredWindow()
+    private func findTarget(_ location: NSPoint) -> ThumbnailView? {
+        for i in 0..<Windows.list.count {
+            let view = ThumbnailsView.recycledViews[i]
+            let frame = view.frame
+            let expandedFrame = CGRect(x: frame.minX - (App.shared.userInterfaceLayoutDirection == .leftToRight ? 0 : 1), y: frame.minY, width: frame.width + 1, height: frame.height + 1)
+            if expandedFrame.contains(location) {
+                return view
+            }
+        }
+        return nil
     }
 
     /// Checks whether the mouse pointer is within the padding area around a thumbnail.