build: add wayland

build.zig

@@ -24,6 +24,8 @@ const XCFrameworkStep = @import("src/build/XCFrameworkStep.zig");
 const Version = @import("src/build/Version.zig");
 const Command = @import("src/Command.zig");
 
+const Scanner = @import("zig_wayland").Scanner;
+
 comptime {
     // This is the required Zig version for building this project. We allow
     // any patch version but the major and minor must match exactly.
@@ -105,19 +107,19 @@ pub fn build(b: *std.Build) !void {
         "Enables the use of Adwaita when using the GTK rendering backend.",
     ) orelse true;
 
-    config.x11 = b.option(
+    var x11 = false;
-        bool,
+    var wayland = false;
-        "gtk-x11",
-        "Enables linking against X11 libraries when using the GTK rendering backend.",
-    ) orelse x11: {
-        if (target.result.os.tag != .linux) break :x11 false;
 
+    if (target.result.os.tag == .linux) pkgconfig: {
         var pkgconfig = std.process.Child.init(&.{ "pkg-config", "--variable=targets", "gtk4" }, b.allocator);
 
         pkgconfig.stdout_behavior = .Pipe;
         pkgconfig.stderr_behavior = .Pipe;
 
-        try pkgconfig.spawn();
+        pkgconfig.spawn() catch |err| {
+            std.log.warn("failed to spawn pkg-config - disabling X11 and Wayland integrations: {}", .{err});
+            break :pkgconfig;
+        };
 
         const output_max_size = 50 * 1024;
 
@@ -139,18 +141,31 @@ pub fn build(b: *std.Build) !void {
         switch (term) {
             .Exited => |code| {
                 if (code == 0) {
-                    if (std.mem.indexOf(u8, stdout.items, "x11")) |_| break :x11 true;
+                    if (std.mem.indexOf(u8, stdout.items, "x11")) |_| x11 = true;
-                    break :x11 false;
+                    if (std.mem.indexOf(u8, stdout.items, "wayland")) |_| wayland = true;
+                } else {
+                    std.log.warn("pkg-config: {s} with code {d}", .{ @tagName(term), code });
+                    return error.Unexpected;
                 }
-                std.log.warn("pkg-config: {s} with code {d}", .{ @tagName(term), code });
-                break :x11 false;
             },
             inline else => |code| {
                 std.log.warn("pkg-config: {s} with code {d}", .{ @tagName(term), code });
                 return error.Unexpected;
             },
         }
-    };
+    }
+
+    config.x11 = b.option(
+        bool,
+        "gtk-x11",
+        "Enables linking against X11 libraries when using the GTK rendering backend.",
+    ) orelse x11;
+
+    config.wayland = b.option(
+        bool,
+        "gtk-wayland",
+        "Enables linking against Wayland libraries when using the GTK rendering backend.",
+    ) orelse wayland;
 
     config.sentry = b.option(
         bool,
@@ -1459,6 +1474,17 @@ fn addDeps(
                 if (config.adwaita) step.linkSystemLibrary2("adwaita-1", dynamic_link_opts);
                 if (config.x11) step.linkSystemLibrary2("X11", dynamic_link_opts);
 
+                if (config.wayland) {
+                    const scanner = Scanner.create(b, .{});
+
+                    const wayland = b.createModule(.{ .root_source_file = scanner.result });
+
+                    scanner.generate("wl_compositor", 1);
+
+                    step.root_module.addImport("wayland", wayland);
+                    step.linkSystemLibrary2("wayland-client", dynamic_link_opts);
+                }
+
                 {
                     const gresource = @import("src/apprt/gtk/gresource.zig");
 

build.zig.zon

@@ -25,6 +25,10 @@
             .url = "https://deps.files.ghostty.org/ziglyph-b89d43d1e3fb01b6074bc1f7fc980324b04d26a5.tar.gz",
             .hash = "12207831bce7d4abce57b5a98e8f3635811cfefd160bca022eb91fe905d36a02cf25",
         },
+        .zig_wayland = .{
+            .url = "https://codeberg.org/ifreund/zig-wayland/archive/a5e2e9b6a6d7fba638ace4d4b24a3b576a02685b.tar.gz",
+            .hash = "1220d41b23ae70e93355bb29dac1c07aa6aeb92427a2dffc4375e94b4de18111248c",
+        },
 
         // C libs
         .cimgui = .{ .path = "./pkg/cimgui" },
@@ -64,5 +68,9 @@
             .url = "git+https://github.com/vancluever/z2d?ref=v0.4.0#4638bb02a9dc41cc2fb811f092811f6a951c752a",
             .hash = "12201f0d542e7541cf492a001d4d0d0155c92f58212fbcb0d224e95edeba06b5416a",
         },
+        .plasma_wayland_protocols = .{
+            .url = "git+https://invent.kde.org/libraries/plasma-wayland-protocols.git?ref=master#db525e8f9da548cffa2ac77618dd0fbe7f511b86",
+            .hash = "12207e0851c12acdeee0991e893e0132fc87bb763969a585dc16ecca33e88334c566",
+        },
     },
 }

nix/devShell.nix

@@ -51,6 +51,9 @@
   pandoc,
   hyperfine,
   typos,
+  wayland,
+  wayland-scanner,
+  wayland-protocols,
 }: let
   # See package.nix. Keep in sync.
   rpathLibs =
@@ -80,6 +83,7 @@
       libadwaita
       gtk4
       glib
+      wayland
     ];
 in
   mkShell {
@@ -153,6 +157,9 @@ in
         libadwaita
         gtk4
         glib
+        wayland
+        wayland-scanner
+        wayland-protocols
       ];
 
     # This should be set onto the rpath of the ghostty binary if you want

nix/package.nix

@@ -10,10 +10,6 @@
   oniguruma,
   zlib,
   libGL,
-  libX11,
-  libXcursor,
-  libXi,
-  libXrandr,
   glib,
   gtk4,
   libadwaita,
@@ -26,7 +22,17 @@
   pandoc,
   revision ? "dirty",
   optimize ? "Debug",
-  x11 ? true,
+
+  enableX11 ? true,
+  libX11,
+  libXcursor,
+  libXi,
+  libXrandr,
+
+  enableWayland ? true,
+  wayland,
+  wayland-protocols,
+  wayland-scanner,
 }: let
   # The Zig hook has no way to select the release type without actual
   # overriding of the default flags.
@@ -114,14 +120,19 @@ in
     version = "1.0.2";
     inherit src;
 
-    nativeBuildInputs = [
+    nativeBuildInputs =
-      git
+      [
-      ncurses
+        git
-      pandoc
+        ncurses
-      pkg-config
+        pandoc
-      zig_hook
+        pkg-config
-      wrapGAppsHook4
+        zig_hook
-    ];
+        wrapGAppsHook4
+      ]
+      ++ lib.optionals enableWayland [
+        wayland-scanner
+        wayland-protocols
+      ];
 
     buildInputs =
       [
@@ -142,16 +153,19 @@ in
         glib
         gsettings-desktop-schemas
       ]
-      ++ lib.optionals x11 [
+      ++ lib.optionals enableX11 [
         libX11
         libXcursor
         libXi
         libXrandr
+      ]
+      ++ lib.optionals enableWayland [
+        wayland
       ];
 
     dontConfigure = true;
 
-    zigBuildFlags = "-Dversion-string=${finalAttrs.version}-${revision}-nix -Dgtk-x11=${lib.boolToString x11}";
+    zigBuildFlags = "-Dversion-string=${finalAttrs.version}-${revision}-nix -Dgtk-x11=${lib.boolToString enableX11} -Dgtk-wayland=${lib.boolToString enableWayland}";
 
     preBuild = ''
       rm -rf $ZIG_GLOBAL_CACHE_DIR

src/apprt/gtk/App.zig

@@ -37,6 +37,7 @@ const version = @import("version.zig");
 const inspector = @import("inspector.zig");
 const key = @import("key.zig");
 const x11 = @import("x11.zig");
+const wayland = @import("wayland.zig");
 const testing = std.testing;
 
 const log = std.log.scoped(.gtk);
@@ -73,6 +74,9 @@ running: bool = true,
 /// Xkb state (X11 only). Will be null on Wayland.
 x11_xkb: ?x11.Xkb = null,
 
+/// Wayland app state. Will be null on X11.
+wayland: ?wayland.AppState = null,
+
 /// The base path of the transient cgroup used to put all surfaces
 /// into their own cgroup. This is only set if cgroups are enabled
 /// and initialization was successful.
@@ -397,6 +401,10 @@ pub fn init(core_app: *CoreApp, opts: Options) !App {
         break :x11_xkb try x11.Xkb.init(display);
     };
 
+    // Initialize Wayland state
+    var wl = wayland.AppState.init(display);
+    if (wl) |*w| try w.register();
+
     // This just calls the `activate` signal but its part of the normal startup
     // routine so we just call it, but only if the config allows it (this allows
     // for launching Ghostty in the "background" without immediately opening
@@ -422,6 +430,7 @@ pub fn init(core_app: *CoreApp, opts: Options) !App {
         .ctx = ctx,
         .cursor_none = cursor_none,
         .x11_xkb = x11_xkb,
+        .wayland = wl,
         .single_instance = single_instance,
         // If we are NOT the primary instance, then we never want to run.
         // This means that another instance of the GTK app is running and

src/apprt/gtk/Window.zig

@@ -25,6 +25,7 @@ const gtk_key = @import("key.zig");
 const Notebook = @import("notebook.zig").Notebook;
 const HeaderBar = @import("headerbar.zig").HeaderBar;
 const version = @import("version.zig");
+const wayland = @import("wayland.zig");
 
 const log = std.log.scoped(.gtk);
 
@@ -55,6 +56,8 @@ toast_overlay: ?*c.GtkWidget,
 /// See adwTabOverviewOpen for why we have this.
 adw_tab_overview_focus_timer: ?c.guint = null,
 
+wayland: ?wayland.SurfaceState,
+
 pub fn create(alloc: Allocator, app: *App) !*Window {
     // Allocate a fixed pointer for our window. We try to minimize
     // allocations but windows and other GUI requirements are so minimal
@@ -79,6 +82,7 @@ pub fn init(self: *Window, app: *App) !void {
         .notebook = undefined,
         .context_menu = undefined,
         .toast_overlay = undefined,
+        .wayland = null,
     };
 
     // Create the window
@@ -290,6 +294,7 @@ pub fn init(self: *Window, app: *App) !void {
 
     // All of our events
     _ = c.g_signal_connect_data(self.context_menu, "closed", c.G_CALLBACK(&gtkRefocusTerm), self, null, c.G_CONNECT_DEFAULT);
+    _ = c.g_signal_connect_data(window, "realize", c.G_CALLBACK(&gtkRealize), self, null, c.G_CONNECT_DEFAULT);
     _ = c.g_signal_connect_data(window, "close-request", c.G_CALLBACK(&gtkCloseRequest), self, null, c.G_CONNECT_DEFAULT);
     _ = c.g_signal_connect_data(window, "destroy", c.G_CALLBACK(&gtkDestroy), self, null, c.G_CONNECT_DEFAULT);
     _ = c.g_signal_connect_data(ec_key_press, "key-pressed", c.G_CALLBACK(&gtkKeyPressed), self, null, c.G_CONNECT_DEFAULT);
@@ -424,6 +429,8 @@ fn initActions(self: *Window) void {
 pub fn deinit(self: *Window) void {
     c.gtk_widget_unparent(@ptrCast(self.context_menu));
 
+    if (self.wayland) |*wl| wl.deinit();
+
     if (self.adw_tab_overview_focus_timer) |timer| {
         _ = c.g_source_remove(timer);
     }
@@ -551,6 +558,16 @@ pub fn sendToast(self: *Window, title: [:0]const u8) void {
     c.adw_toast_overlay_add_toast(@ptrCast(toast_overlay), toast);
 }
 
+fn gtkRealize(v: *c.GtkWindow, ud: ?*anyopaque) callconv(.C) bool {
+    const self = userdataSelf(ud.?);
+
+    if (self.app.wayland) |*wl| {
+        self.wayland = wayland.SurfaceState.init(v, wl);
+    }
+
+    return true;
+}
+
 // Note: we MUST NOT use the GtkButton parameter because gtkActionNewTab
 // sends an undefined value.
 fn gtkTabNewClick(_: *c.GtkButton, ud: ?*anyopaque) callconv(.C) void {

src/apprt/gtk/c.zig

@@ -14,6 +14,9 @@ pub const c = @cImport({
         // Xkb for X11 state handling
         @cInclude("X11/XKBlib.h");
     }
+    if (build_options.wayland) {
+        @cInclude("gdk/wayland/gdkwayland.h");
+    }
 
     // generated header files
     @cInclude("ghostty_resources.h");

src/apprt/gtk/wayland.zig

@@ -0,0 +1,90 @@
+const std = @import("std");
+const c = @import("c.zig").c;
+const wayland = @import("wayland");
+const wl = wayland.client.wl;
+const build_options = @import("build_options");
+
+const log = std.log.scoped(.gtk_wayland);
+
+/// Wayland state that contains application-wide Wayland objects (e.g. wl_display).
+pub const AppState = struct {
+    display: *wl.Display,
+
+    pub fn init(display: ?*c.GdkDisplay) ?AppState {
+        if (comptime !build_options.wayland) return null;
+
+        // It should really never be null
+        const display_ = display orelse return null;
+
+        // Check if we're actually on Wayland
+        if (c.g_type_check_instance_is_a(
+            @ptrCast(@alignCast(display_)),
+            c.gdk_wayland_display_get_type(),
+        ) == 0)
+            return null;
+
+        const wl_display: *wl.Display = @ptrCast(c.gdk_wayland_display_get_wl_display(display_) orelse return null);
+
+        return .{
+            .display = wl_display,
+        };
+    }
+
+    pub fn register(self: *AppState) !void {
+        const registry = try self.display.getRegistry();
+
+        registry.setListener(*AppState, registryListener, self);
+        if (self.display.roundtrip() != .SUCCESS) return error.RoundtripFailed;
+
+        log.debug("app wayland init={}", .{self});
+    }
+};
+
+/// Wayland state that contains Wayland objects associated with a window (e.g. wl_surface).
+pub const SurfaceState = struct {
+    app_state: *AppState,
+    surface: *wl.Surface,
+
+    pub fn init(window: *c.GtkWindow, app_state: *AppState) ?SurfaceState {
+        if (comptime !build_options.wayland) return null;
+
+        const surface = c.gtk_native_get_surface(@ptrCast(window)) orelse return null;
+
+        // Check if we're actually on Wayland
+        if (c.g_type_check_instance_is_a(
+            @ptrCast(@alignCast(surface)),
+            c.gdk_wayland_surface_get_type(),
+        ) == 0)
+            return null;
+
+        const wl_surface: *wl.Surface = @ptrCast(c.gdk_wayland_surface_get_wl_surface(surface) orelse return null);
+
+        return .{
+            .app_state = app_state,
+            .surface = wl_surface,
+        };
+    }
+
+    pub fn deinit(self: *SurfaceState) void {
+    }
+};
+
+fn registryListener(registry: *wl.Registry, event: wl.Registry.Event, state: *AppState) void {
+    switch (event) {
+        .global => |global| {
+            log.debug("got global interface={s}", .{global.interface});
+        },
+        .global_remove => {},
+    }
+}
+
+fn bindInterface(comptime T: type, registry: *wl.Registry, global: anytype, version: u32) ?*T {
+    if (std.mem.orderZ(u8, global.interface, T.interface.name) == .eq) {
+        return registry.bind(global.name, T, version) catch |err| {
+            log.warn("encountered error={} while binding interface {s}", .{ err, global.interface });
+            return null;
+        };
+    } else {
+        return null;
+    }
+}

src/build_config.zig

@@ -23,6 +23,7 @@ pub const BuildConfig = struct {
     flatpak: bool = false,
     adwaita: bool = false,
     x11: bool = false,
+    wayland: bool = false,
     sentry: bool = true,
     app_runtime: apprt.Runtime = .none,
     renderer: rendererpkg.Impl = .opengl,
@@ -44,6 +45,7 @@ pub const BuildConfig = struct {
         step.addOption(bool, "flatpak", self.flatpak);
         step.addOption(bool, "adwaita", self.adwaita);
         step.addOption(bool, "x11", self.x11);
+        step.addOption(bool, "wayland", self.wayland);
         step.addOption(bool, "sentry", self.sentry);
         step.addOption(apprt.Runtime, "app_runtime", self.app_runtime);
         step.addOption(font.Backend, "font_backend", self.font_backend);

src/cli/version.zig

@@ -68,6 +68,14 @@ pub fn run(alloc: Allocator) !u8 {
         } else {
             try stdout.print("  - libX11     : disabled\n", .{});
         }
+
+        // We say `libwayland` since it is possible to build Ghostty without
+        // Wayland integration but with Wayland-enabled GTK
+        if (comptime build_options.wayland) {
+            try stdout.print("  - libwayland : enabled\n", .{});
+        } else {
+            try stdout.print("  - libwayland : disabled\n", .{});
+        }
     }
     return 0;
 }