config: macos-icon configurations

include/ghostty.h

@@ -342,6 +342,7 @@ typedef struct {
   uint8_t b;
 } ghostty_config_color_s;
 
+// config.ColorList
 typedef struct {
   const ghostty_config_color_s* colors;
   size_t len;

macos/Sources/App/macOS/AppDelegate.swift

@@ -528,7 +528,7 @@ class AppDelegate: NSObject,
         }
 
         if let colorizedIcon = ColorizedGhosttyIcon(
-            screenColors: [.purple, .blue],
+            screenColors: [],
             ghostColor: .yellow
         ).makeImage() {
             self.appIcon = colorizedIcon

macos/Sources/Helpers/OSColor+Extension.swift

@@ -47,6 +47,37 @@ extension OSColor {
 #endif
     }
 
+    /// Create an OSColor from a hex string.
+    convenience init?(hex: String) {
+        var cleanedHex = hex.trimmingCharacters(in: .whitespacesAndNewlines)
+
+        // Remove `#` if present
+        if cleanedHex.hasPrefix("#") {
+            cleanedHex.removeFirst()
+        }
+
+        guard cleanedHex.count == 6 || cleanedHex.count == 8 else { return nil }
+
+        let scanner = Scanner(string: cleanedHex)
+        var hexNumber: UInt64 = 0
+        guard scanner.scanHexInt64(&hexNumber) else { return nil }
+
+        let red, green, blue, alpha: CGFloat
+        if cleanedHex.count == 8 {
+            alpha = CGFloat((hexNumber & 0xFF000000) >> 24) / 255
+            red   = CGFloat((hexNumber & 0x00FF0000) >> 16) / 255
+            green = CGFloat((hexNumber & 0x0000FF00) >> 8) / 255
+            blue  = CGFloat(hexNumber & 0x000000FF) / 255
+        } else { // 6 characters
+            alpha = 1.0
+            red   = CGFloat((hexNumber & 0xFF0000) >> 16) / 255
+            green = CGFloat((hexNumber & 0x00FF00) >> 8) / 255
+            blue  = CGFloat(hexNumber & 0x0000FF) / 255
+        }
+
+        self.init(red: red, green: green, blue: blue, alpha: alpha)
+    }
+
     func darken(by amount: CGFloat) -> OSColor {
         var h: CGFloat = 0, s: CGFloat = 0, b: CGFloat = 0, a: CGFloat = 0
         self.getHue(&h, saturation: &s, brightness: &b, alpha: &a)

src/config/Config.zig

@@ -16,6 +16,7 @@ const build_config = @import("../build_config.zig");
 const assert = std.debug.assert;
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
+const build_config = @import("../build_config.zig");
 const global_state = &@import("../global.zig").state;
 const fontpkg = @import("../font/main.zig");
 const inputpkg = @import("../input.zig");
@@ -1675,6 +1676,40 @@ keybind: Keybinds = .{},
 /// you may want to disable it.
 @"macos-secure-input-indication": bool = true,
 
+/// Customize the macOS app icon.
+///
+/// This only affects the icon that appears in the dock, application
+/// switcher, Activity Monitor, etc. This does not affect the icon
+/// in Finder because that is controlled by a hardcoded value in the
+/// signed application bundle and can't be changed at runtime.
+///
+/// Valid values:
+///
+///  * `official` - Use the official Ghostty icon.
+///  * `custom-color` - Use the official Ghostty icon but with custom
+///    colors applied to various layers. The custom colors must be
+///    specified using `macos-icon-layer-color`.
+///
+@"macos-icon": MacAppIcon = .official,
+
+/// The color of the ghost in the macOS app icon.
+///
+/// The format of the color is the same as the `background` configuration;
+/// see that for more information.
+///
+/// This only has an effect when `macos-icon` is set to `custom-color`.
+@"macos-icon-ghost-color": ?Color = null,
+
+/// The color of the screen in the macOS app icon.
+///
+/// The screen is a gradient so you can specify multiple colors that
+/// make up the gradient. Colors should be separated by commas. The
+/// format of the color is the same as the `background` configuration;
+/// see that for more information.
+///
+/// This only has an effect when `macos-icon` is set to `custom-color`.
+@"macos-icon-screen-color": ?ColorList = null,
+
 /// Put every surface (tab, split, window) into a dedicated Linux cgroup.
 ///
 /// This makes it so that resource management can be done on a per-surface
@@ -3577,12 +3612,17 @@ pub const Color = struct {
         var buf: [128]u8 = undefined;
         try formatter.formatEntry(
             []const u8,
-            std.fmt.bufPrint(
-                &buf,
+            try self.formatBuf(&buf),
+        );
+    }
+
+    /// Format the color as a string.
+    pub fn formatBuf(self: Color, buf: []u8) ![]const u8 {
+        return std.fmt.bufPrint(
+            buf,
             "#{x:0>2}{x:0>2}{x:0>2}",
             .{ self.r, self.g, self.b },
-            ) catch return error.OutOfMemory,
-        );
+        ) catch error.OutOfMemory;
     }
 
     /// fromHex parses a color from a hex value such as #RRGGBB. The "#"
@@ -3637,6 +3677,130 @@ pub const Color = struct {
     }
 };
 
+pub const ColorList = struct {
+    const Self = @This();
+
+    colors: std.ArrayListUnmanaged(Color) = .{},
+    colors_c: std.ArrayListUnmanaged(Color.C) = .{},
+
+    /// ghostty_config_color_list_s
+    pub const C = extern struct {
+        colors: [*]Color.C,
+        len: usize,
+    };
+
+    pub fn cval(self: *const Self) C {
+        return .{
+            .colors = self.colors_c.items.ptr,
+            .len = self.colors_c.items.len,
+        };
+    }
+
+    pub fn parseCLI(
+        self: *Self,
+        alloc: Allocator,
+        input_: ?[]const u8,
+    ) !void {
+        const input = input_ orelse return error.ValueRequired;
+        if (input.len == 0) return error.ValueRequired;
+
+        // Whenever a color list is set, we reset the list
+        self.colors.clearRetainingCapacity();
+
+        // Split the input by commas and parse each color
+        var it = std.mem.tokenizeScalar(u8, input, ',');
+        var count: usize = 0;
+        while (it.next()) |raw| {
+            count += 1;
+            if (count > 64) return error.InvalidValue;
+
+            const color = try Color.parseCLI(raw);
+            try self.colors.append(alloc, color);
+            try self.colors_c.append(alloc, color.cval());
+        }
+
+        // If no colors were parsed, we need to return an error
+        if (self.colors.items.len == 0) return error.InvalidValue;
+
+        assert(self.colors.items.len == self.colors_c.items.len);
+    }
+
+    pub fn clone(
+        self: *const Self,
+        alloc: Allocator,
+    ) Allocator.Error!Self {
+        return .{
+            .colors = try self.colors.clone(alloc),
+        };
+    }
+
+    /// Compare if two of our value are requal. Required by Config.
+    pub fn equal(self: Self, other: Self) bool {
+        const itemsA = self.colors.items;
+        const itemsB = other.colors.items;
+        if (itemsA.len != itemsB.len) return false;
+        for (itemsA, itemsB) |a, b| {
+            if (!a.equal(b)) return false;
+        } else return true;
+    }
+
+    /// Used by Formatter
+    pub fn formatEntry(self: Self, formatter: anytype) !void {
+        // If no items, we want to render an empty field.
+        if (self.colors.items.len == 0) {
+            try formatter.formatEntry(void, {});
+            return;
+        }
+
+        // Build up the value of our config. Our buffer size should be
+        // sized to contain all possible maximum values.
+        var buf: [1024]u8 = undefined;
+        var fbs = std.io.fixedBufferStream(&buf);
+        var writer = fbs.writer();
+        for (self.colors.items, 0..) |color, i| {
+            var color_buf: [128]u8 = undefined;
+            const color_str = try color.formatBuf(&color_buf);
+            if (i != 0) try writer.writeByte(',');
+            try writer.writeAll(color_str);
+        }
+
+        try formatter.formatEntry(
+            []const u8,
+            fbs.getWritten(),
+        );
+    }
+
+    test "parseCLI" {
+        const testing = std.testing;
+        var arena = ArenaAllocator.init(testing.allocator);
+        defer arena.deinit();
+        const alloc = arena.allocator();
+
+        var p: Self = .{};
+        try p.parseCLI(alloc, "black,white");
+        try testing.expectEqual(2, p.colors.items.len);
+
+        // Error cases
+        try testing.expectError(error.ValueRequired, p.parseCLI(alloc, null));
+        try testing.expectError(error.InvalidValue, p.parseCLI(alloc, " "));
+    }
+
+    test "format" {
+        const testing = std.testing;
+        var buf = std.ArrayList(u8).init(testing.allocator);
+        defer buf.deinit();
+
+        var arena = ArenaAllocator.init(testing.allocator);
+        defer arena.deinit();
+        const alloc = arena.allocator();
+
+        var p: Self = .{};
+        try p.parseCLI(alloc, "black,white");
+        try p.formatEntry(formatterpkg.entryFormatter("a", buf.writer()));
+        try std.testing.expectEqualSlices(u8, "a = #000000,#ffffff\n", buf.items);
+    }
+};
+
 /// Palette is the 256 color palette for 256-color mode. This is still
 /// used by many terminal applications.
 pub const Palette = struct {
@@ -4922,6 +5086,16 @@ pub const MacTitlebarProxyIcon = enum {
     hidden,
 };
 
+/// See macos-icon
+///
+/// Note: future versions of Ghostty can support a custom icon with
+/// path by changing this to a tagged union, which doesn't change our
+/// format at all.
+pub const MacAppIcon = enum {
+    official,
+    @"custom-color",
+};
+
 /// See gtk-single-instance
 pub const GtkSingleInstance = enum {
     desktop,