From aa48290db3966330ccf00a3f22984cbb4ece64c6 Mon Sep 17 00:00:00 2001
From: Lurkie <tiny.bed5655@fastmail.com>
Date: Sat, 16 Aug 2025 19:24:55 -0600
Subject: [PATCH] feat: add XDG decoration support

---
 build.zig       |  3 +++
 src/wayland.zig | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/build.zig b/build.zig
index c176e64..0920089 100644
--- a/build.zig
+++ b/build.zig
@@ -70,6 +70,9 @@ pub fn build(b: *std.Build) !void {
     scanner.addSystemProtocol("stable/xdg-shell/xdg-shell.xml");
     scanner.generate("xdg_wm_base", 1);
 
+    scanner.addSystemProtocol("unstable/xdg-decoration/xdg-decoration-unstable-v1.xml");
+    scanner.generate("zxdg_decoration_manager_v1", 1);
+
     exe.root_module.addImport("wayland", wayland);
     exe.linkLibC();
     exe.linkSystemLibrary("wayland-client");
diff --git a/src/wayland.zig b/src/wayland.zig
index 62fa8fd..c2a316c 100644
--- a/src/wayland.zig
+++ b/src/wayland.zig
@@ -19,6 +19,7 @@ const Config = configpkg.Config;
 const wayland = @import("wayland");
 const wl = wayland.client.wl;
 const xdg = wayland.client.xdg;
+const zxdg = wayland.client.zxdg;
 const zwp = wayland.client.zwp;
 const wp = wayland.client.wp;
 
@@ -42,6 +43,7 @@ const Context = struct {
     compositor: ?*wl.Compositor,
     wm_base: ?*xdg.WmBase,
     data_device_manager: ?*wl.DataDeviceManager,
+    decoration_manager: ?*zxdg.DecorationManagerV1,
     selection_device_manager: ?*zwp.PrimarySelectionDeviceManagerV1,
     cursor_shape_manager: ?*wp.CursorShapeManagerV1,
     surface_map: *SurfaceMap,
@@ -684,6 +686,8 @@ fn registryListener(registry: *wl.Registry, event: wl.Registry.Event, context: *
                 context.selection_device_manager = registry.bind(global.name, zwp.PrimarySelectionDeviceManagerV1, 1) catch return;
             } else if (std.mem.orderZ(u8, global.interface, wp.CursorShapeManagerV1.interface.name) == .eq) {
                 context.cursor_shape_manager = registry.bind(global.name, wp.CursorShapeManagerV1, 1) catch return;
+            } else if (std.mem.orderZ(u8, global.interface, zxdg.DecorationManagerV1.interface.name) == .eq) {
+                context.decoration_manager = registry.bind(global.name, zxdg.DecorationManagerV1, 1) catch return;
             }
         },
         .global_remove => {},
@@ -697,6 +701,7 @@ pub const App = struct {
     wm_base: *xdg.WmBase,
     registry: *wl.Registry,
     data_device_manager: *wl.DataDeviceManager,
+    decoration_manager: ?*zxdg.DecorationManagerV1,
     selection_device_manager: *zwp.PrimarySelectionDeviceManagerV1,
     data_device: *wl.DataDevice,
     selection_device: *zwp.PrimarySelectionDeviceV1,
@@ -733,6 +738,7 @@ pub const App = struct {
             .compositor = null,
             .wm_base = null,
             .data_device_manager = null,
+            .decoration_manager = null,
             .selection_device_manager = null,
             .cursor_shape_manager = null,
             .surface_map = surface_map,
@@ -839,6 +845,7 @@ pub const App = struct {
             .wm_base = wm_base,
             .data_device_manager = data_device_manager,
             .data_device = data_device,
+            .decoration_manager = context.decoration_manager,
             .selection_device_manager = selection_device_manager,
             .selection_device = selection_device,
             .cursor_shape_manager = cursor_shape_manager,
@@ -1278,6 +1285,7 @@ pub const Surface = struct {
     wl_surface: *wl.Surface,
     xdg_surface: *xdg.Surface,
     xdg_toplevel: *xdg.Toplevel,
+    xdg_decoration: ?*zxdg.ToplevelDecorationV1,
 
     data_offer: ?*wl.DataOffer,
     selection_offer: ?*zwp.PrimarySelectionOfferV1,
@@ -1338,6 +1346,7 @@ pub const Surface = struct {
         self.pressed_key = null;
         self.repeat_rate = 0;
         self.repeat_delay = 0;
+        self.xdg_decoration = null;
 
         self.wl_surface = try app.compositor.createSurface();
         errdefer self.wl_surface.destroy();
@@ -1348,6 +1357,11 @@ pub const Surface = struct {
         self.xdg_surface.setListener(*Surface, xdgSurfaceListener, self);
         self.xdg_toplevel.setListener(*Surface, xdgToplevelListener, self);
 
+        if (app.decoration_manager) |decoration_manager| {
+            self.xdg_decoration = try decoration_manager.getToplevelDecoration(self.xdg_toplevel);
+            self.xdg_decoration.?.setMode(.server_side);
+        }
+
         const app_id = app.config.class orelse "com.mitchellh.ghostty";
         self.xdg_toplevel.setAppId(app_id);
 
@@ -1416,6 +1430,10 @@ pub const Surface = struct {
         // Clean up our core surface so that all the rendering and IO stop.
         self.core_surface.deinit();
 
+        if (self.xdg_decoration) |decor| {
+            decor.destroy();
+        }
+
         self.xdg_toplevel.destroy();
         self.xdg_surface.destroy();
         self.wl_surface.destroy();