fix: app icons could sometimes be invisible (closes #5226)

resources/l10n/ko.lproj/Localizable.strings

@@ -188,7 +188,7 @@
 "Show standard tabs as windows" = "표준 탭을 윈도우로 보이기";
 "Show standard tabs as windows:" = "표준 탭을 윈도우로 보여주기:";
 "Show titles" = "제목 표시";
-"Show windows from applications" = "윈도우을 표시할 앱";
+"Show windows from applications" = "윈도우를 표시할 앱";
 "Show windows from screens" = "윈도우를 표시할 화면";
 "Show windows from Spaces" = "윈도우를 표시할 Space";
 "Show windows from:" = "창을 표시할 항목:";

src/logic/Application.swift

@@ -45,18 +45,29 @@ class Application: NSObject {
         return 0
     }()
 
+    /// Converting NSImage to CGImage may seem simple, but it's actually very tricky. Lots of time has been put to make it work robustly
+    /// The RunningApplication.icon can have store bitmaps or vectors. We have to rasterize into pixels. This is not easy as there are many APIs:
+    ///   * icon.cgImage(forProposedRect:) > context.draw -> only API which works
+    ///   * icon.cgImage(forProposedRect:) > cgImage.draw -> returns nil for some users (could never reproduce it locally)
+    ///   * icon.draw() -> returns nil for some users (could never reproduce it locally)
+    ///   * icon.bestRepresentation() > bestRep.draw(in:) -> returns nil for some users (could never reproduce it locally)
+    /// MacOS Big Sur also introduced a constant padding around app icons. It was later increased with Tahoe. We have to crop it
     static func appIconWithoutPadding(_ icon: NSImage?) -> CGImage? {
         guard let icon else { return nil }
         let finalWidth = max(ThumbnailsPanel.maxPossibleAppIconSize.width, ThumbnailsPanel.maxPossibleAppIconSize.height)
+        // we hardcode cropping values based on a reference 1024 icon, and depending on the macOS version
         let padding = appIconPadding * (finalWidth / (1024 - appIconPadding * 2))
+        // we need a bigger image size, since we'll crop to reach finalWidth
         let sourceWidth = finalWidth + padding * 2
-        guard let context = CGContext(data: nil, width: Int(finalWidth), height: Int(finalWidth), bitsPerComponent: 8, bytesPerRow: 0, space: CGColorSpaceCreateDeviceRGB(), bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else { return nil }
+        // we ask the NSImage for the closest image it has to our desired size. It's likely to return a 1024x1024 or 512x512 image; whichever is closest
+        var proposedRect = CGRect(origin: .zero, size: NSSize(width: sourceWidth, height: sourceWidth))
+        guard let cgImage = icon.cgImage(forProposedRect: &proposedRect, context: nil, hints: [.interpolation: NSImageInterpolation.high]) else { return nil }
+        // we have to crop this image; let's scale our intended padding, given the image size we got
+        let paddingScaled = padding * (CGFloat(cgImage.width) / sourceWidth)
+        guard let image = cgImage.cropping(to: CGRect(x: paddingScaled, y: paddingScaled, width: CGFloat(cgImage.width) - paddingScaled * 2, height: CGFloat(cgImage.height) - paddingScaled * 2).integral),
+              let context = CGContext(data: nil, width: Int(finalWidth), height: Int(finalWidth), bitsPerComponent: 8, bytesPerRow: 0, space: CGColorSpaceCreateDeviceRGB(), bitmapInfo: CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedFirst.rawValue).union(.byteOrder32Little).rawValue) else { return nil }
         context.interpolationQuality = .high
-        let drawRect = CGRect(x: -padding, y: -padding, width: sourceWidth, height: sourceWidth)
-        NSGraphicsContext.saveGraphicsState()
-        NSGraphicsContext.current = NSGraphicsContext(cgContext: context, flipped: false)
-        icon.draw(in: drawRect, from: .zero, operation: .copy, fraction: 1.0, respectFlipped: false, hints: nil)
-        NSGraphicsContext.restoreGraphicsState()
+        context.draw(image, in: CGRect(origin: .zero, size: NSSize(width: finalWidth, height: finalWidth)))
         return context.makeImage()
     }
 

src/logic/Screens.swift

@@ -13,7 +13,7 @@ class Screens {
 }
 
 extension NSScreen {
-    static var preferred: NSScreen = detectPreferred() ?? NSScreen.screens.first!
+    static var preferred = NSScreen.screens.first!
 
     static func updatePreferred() {
         preferred = detectPreferred() ?? NSScreen.screens.first!
@@ -35,7 +35,9 @@ extension NSScreen {
     /// we find the screen with the key window ourselves manually
     static func active() -> NSScreen? {
         guard let frontmostPid = NSWorkspace.shared.frontmostApplication?.processIdentifier,
-              let frontmostApp = Applications.findOrCreate(frontmostPid) else { return nil }
+              // we avoid Applications.findOrCreate() here, because it active() is called very early during launch
+              // we are not ready to create applications yet
+              let frontmostApp = (Applications.list.first { $0.pid == frontmostPid }) else { return nil }
         guard let focusedWindow = frontmostApp.focusedWindow else { return NSScreen.withActiveMenubar() }
         // on the very first summon, this window may not have its spaces updated, which may land the wrong active screen
         focusedWindow.updateSpacesAndScreen()

src/ui/App.swift

@@ -299,6 +299,8 @@ extension App: NSApplicationDelegate {
         BackgroundWork.start()
         NSScreen.updatePreferred()
         Appearance.update()
+        ThumbnailsPanel.updateMaxPossibleThumbnailSize()
+        ThumbnailsPanel.updateMaxPossibleAppIconSize()
         Menubar.initialize()
         MainMenu.loadFromXib()
         self.thumbnailsPanel = ThumbnailsPanel()
@@ -307,8 +309,6 @@ extension App: NSApplicationDelegate {
         Screens.refresh()
         SpacesEvents.observe()
         ScreensEvents.observe()
-        ThumbnailsPanel.updateMaxPossibleThumbnailSize()
-        ThumbnailsPanel.updateMaxPossibleAppIconSize()
         SystemAppearanceEvents.observe()
         SystemScrollerStyleEvents.observe()
         Applications.initialDiscovery()