macos: custom app icon goes into About window

macos/Ghostty.xcodeproj/project.pbxproj

@@ -42,6 +42,7 @@
 		A54B0CE92D0CECD100CBEFF8 /* ColorizedGhosttyIconView.swift in Sources */ = {isa = PBXBuildFile; fileRef = A54B0CE82D0CECD100CBEFF8 /* ColorizedGhosttyIconView.swift */; };
 		A54B0CEB2D0CFB4C00CBEFF8 /* NSImage+Extension.swift in Sources */ = {isa = PBXBuildFile; fileRef = A54B0CEA2D0CFB4A00CBEFF8 /* NSImage+Extension.swift */; };
 		A54B0CED2D0CFB7700CBEFF8 /* ColorizedGhosttyIcon.swift in Sources */ = {isa = PBXBuildFile; fileRef = A54B0CEC2D0CFB7300CBEFF8 /* ColorizedGhosttyIcon.swift */; };
+		A54B0CEF2D0D2E2800CBEFF8 /* ColorizedGhosttyIconImage.swift in Sources */ = {isa = PBXBuildFile; fileRef = A54B0CEE2D0D2E2400CBEFF8 /* ColorizedGhosttyIconImage.swift */; };
 		A54D786C2CA7978E001B19B1 /* BaseTerminalController.swift in Sources */ = {isa = PBXBuildFile; fileRef = A54D786B2CA79788001B19B1 /* BaseTerminalController.swift */; };
 		A55685E029A03A9F004303CE /* AppError.swift in Sources */ = {isa = PBXBuildFile; fileRef = A55685DF29A03A9F004303CE /* AppError.swift */; };
 		A55B7BB829B6F53A0055DE60 /* Package.swift in Sources */ = {isa = PBXBuildFile; fileRef = A55B7BB729B6F53A0055DE60 /* Package.swift */; };
@@ -130,6 +131,7 @@
 		A54B0CE82D0CECD100CBEFF8 /* ColorizedGhosttyIconView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ColorizedGhosttyIconView.swift; sourceTree = "<group>"; };
 		A54B0CEA2D0CFB4A00CBEFF8 /* NSImage+Extension.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NSImage+Extension.swift"; sourceTree = "<group>"; };
 		A54B0CEC2D0CFB7300CBEFF8 /* ColorizedGhosttyIcon.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ColorizedGhosttyIcon.swift; sourceTree = "<group>"; };
+		A54B0CEE2D0D2E2400CBEFF8 /* ColorizedGhosttyIconImage.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ColorizedGhosttyIconImage.swift; sourceTree = "<group>"; };
 		A54D786B2CA79788001B19B1 /* BaseTerminalController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BaseTerminalController.swift; sourceTree = "<group>"; };
 		A55685DF29A03A9F004303CE /* AppError.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppError.swift; sourceTree = "<group>"; };
 		A55B7BB729B6F53A0055DE60 /* Package.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Package.swift; sourceTree = "<group>"; };
@@ -319,6 +321,7 @@
 			isa = PBXGroup;
 			children = (
 				A54B0CEC2D0CFB7300CBEFF8 /* ColorizedGhosttyIcon.swift */,
+				A54B0CEE2D0D2E2400CBEFF8 /* ColorizedGhosttyIconImage.swift */,
 				A54B0CE82D0CECD100CBEFF8 /* ColorizedGhosttyIconView.swift */,
 			);
 			path = "Colorized Ghostty Icon";
@@ -640,6 +643,7 @@
 				A5CDF1932AAF9E0800513312 /* ConfigurationErrorsController.swift in Sources */,
 				A53A6C032CCC1B7F00943E98 /* Ghostty.Action.swift in Sources */,
 				A54B0CED2D0CFB7700CBEFF8 /* ColorizedGhosttyIcon.swift in Sources */,
+				A54B0CEF2D0D2E2800CBEFF8 /* ColorizedGhosttyIconImage.swift in Sources */,
 				A59FB5D12AE0DEA7009128F3 /* MetalView.swift in Sources */,
 				A55685E029A03A9F004303CE /* AppError.swift in Sources */,
 				A599CDB02CF103F60049FA26 /* NSAppearance+Extension.swift in Sources */,

macos/Sources/App/macOS/AppDelegate.swift

@@ -98,6 +98,13 @@ class AppDelegate: NSObject,
     /// The observer for the app appearance.
     private var appearanceObserver: NSKeyValueObservation? = nil
 
+    /// The custom app icon image that is currently in use.
+    @Published private(set) var appIcon: NSImage? = nil {
+        didSet {
+            NSApplication.shared.applicationIconImage = appIcon
+        }
+    }
+
     override init() {
         terminalManager = TerminalManager(ghostty)
         updaterController = SPUStandardUpdaterController(
@@ -524,7 +531,9 @@ class AppDelegate: NSObject,
             screenColors: [.purple, .blue],
             ghostColor: .yellow
         ).makeImage() {
-            NSApplication.shared.applicationIconImage = colorizedIcon
+            self.appIcon = colorizedIcon
+        } else {
+            self.appIcon = nil
         }
     }
 

macos/Sources/Features/About/AboutView.swift

@@ -44,7 +44,7 @@ struct AboutView: View {
 
     var body: some View {
         VStack(alignment: .center) {
-            Image("AppIconImage")
+            ghosttyIconImage()
                 .resizable()
                 .aspectRatio(contentMode: .fit)
                 .frame(height: 128)

macos/Sources/Features/Colorized Ghostty Icon/ColorizedGhosttyIconImage.swift

@@ -0,0 +1,15 @@
+import SwiftUI
+
+extension View {
+    /// Returns the ghostty icon to use for views.
+    func ghosttyIconImage() -> Image {
+        #if os(macOS)
+        if let delegate = NSApplication.shared.delegate as? AppDelegate,
+           let nsImage = delegate.appIcon {
+            return Image(nsImage: nsImage)
+        }
+        #endif
+
+        return Image("AppIconImage")
+    }
+}