Wayland: Add support for the xdg-toplevel-tag protocol

Now you can use --name or its alias --os-window-tag to set the tag.

docs/changelog.rst

@@ -123,6 +123,9 @@ Detailed list of changes
 
 - Panel kitten: A new ``center-sized`` value for :option:`--edge <kitty +kitten panel --edge>` to allow easily creating sized and centered panels
 
+- Wayland: The `kitty --name` flag now sets the XDG *window tag* on compositors
+  that support the `xdg-toplevel-tag <https://wayland.app/protocols/xdg-toplevel-tag-v1>`__ protocol.
+
 
 0.42.0 [2025-05-11]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

glfw/glfw3.h

@@ -1056,6 +1056,7 @@ typedef enum {
 
 #define GLFW_WAYLAND_APP_ID         0x00025001
 #define GLFW_WAYLAND_BGCOLOR        0x00025002
+#define GLFW_WAYLAND_WINDOW_TAG     0x00025003
 /*! @} */
 
 #define GLFW_NO_API                          0

glfw/internal.h

@@ -331,7 +331,7 @@ struct _GLFWwndconfig
         char      instanceName[256];
     } x11;
     struct {
-        char      appId[256];
+        char      appId[256], windowTag[256];
         uint32_t  bgcolor;
     } wl;
 };

glfw/source-info.json

@@ -86,6 +86,7 @@
       "unstable/idle-inhibit/idle-inhibit-unstable-v1.xml",
       "staging/xdg-toplevel-icon/xdg-toplevel-icon-v1.xml",
       "staging/xdg-system-bell/xdg-system-bell-v1.xml",
+      "staging/xdg-toplevel-tag/xdg-toplevel-tag-v1.xml",
 
       "kwin-blur-v1.xml",
       "wlr-layer-shell-unstable-v1.xml"

glfw/window.c

@@ -495,6 +495,10 @@ GLFWAPI void glfwWindowHintString(int hint, const char* value)
             strncpy(_glfw.hints.window.wl.appId, value,
                     sizeof(_glfw.hints.window.wl.appId) - 1);
             return;
+        case GLFW_WAYLAND_WINDOW_TAG:
+            strncpy(_glfw.hints.window.wl.windowTag, value,
+                    sizeof(_glfw.hints.window.wl.windowTag) - 1);
+            return;
     }
 
     _glfwInputError(GLFW_INVALID_ENUM, "Invalid window hint string 0x%08X", hint);

glfw/wl_init.c

@@ -605,6 +605,8 @@ static void registryHandleGlobal(void* data UNUSED,
     }
     else if (is(xdg_system_bell_v1)) {
         _glfw.wl.xdg_system_bell_v1 = wl_registry_bind(registry, name, &xdg_system_bell_v1_interface, 1);
+    } else if (is(xdg_toplevel_tag_manager_v1)) {
+        _glfw.wl.xdg_toplevel_tag_manager_v1 = wl_registry_bind(registry, name, &xdg_toplevel_tag_manager_v1_interface, 1);
     }
 #undef is
 }
@@ -716,6 +718,7 @@ get_compositor_missing_capabilities(void) {
     C(cursor_shape, wp_cursor_shape_manager_v1); C(layer_shell, zwlr_layer_shell_v1);
     C(single_pixel_buffer, wp_single_pixel_buffer_manager_v1); C(preferred_scale, has_preferred_buffer_scale);
     C(idle_inhibit, idle_inhibit_manager); C(icon, xdg_toplevel_icon_manager_v1); C(bell, xdg_system_bell_v1);
+    C(window-tag, xdg_toplevel_tag_manager_v1);
     if (_glfw.wl.xdg_wm_base_version < 6) p += snprintf(p, sizeof(buf) - (p - buf), "%s ", "window-state-suspended");
     if (_glfw.wl.xdg_wm_base_version < 5) p += snprintf(p, sizeof(buf) - (p - buf), "%s ", "window-capabilities");
 #undef C
@@ -894,6 +897,8 @@ void _glfwPlatformTerminate(void)
         xdg_toplevel_icon_manager_v1_destroy(_glfw.wl.xdg_toplevel_icon_manager_v1);
     if (_glfw.wl.xdg_system_bell_v1)
         xdg_system_bell_v1_destroy(_glfw.wl.xdg_system_bell_v1);
+    if (_glfw.wl.xdg_toplevel_tag_manager_v1)
+        xdg_toplevel_tag_manager_v1_destroy(_glfw.wl.xdg_toplevel_tag_manager_v1);
     if (_glfw.wl.wp_single_pixel_buffer_manager_v1)
         wp_single_pixel_buffer_manager_v1_destroy(_glfw.wl.wp_single_pixel_buffer_manager_v1);
     if (_glfw.wl.wp_cursor_shape_manager_v1)

glfw/wl_platform.h

@@ -68,6 +68,7 @@ typedef VkBool32 (APIENTRY *PFN_vkGetPhysicalDeviceWaylandPresentationSupportKHR
 #include "wayland-idle-inhibit-unstable-v1-client-protocol.h"
 #include "wayland-xdg-toplevel-icon-v1-client-protocol.h"
 #include "wayland-xdg-system-bell-v1-client-protocol.h"
+#include "wayland-xdg-toplevel-tag-v1-client-protocol.h"
 
 #define _glfw_dlopen(name) dlopen(name, RTLD_LAZY | RTLD_LOCAL)
 #define _glfw_dlclose(handle) dlclose(handle)
@@ -210,7 +211,7 @@ typedef struct _GLFWwindowWayland
     double                      cursorPosX, cursorPosY, allCursorPosX, allCursorPosY;
 
     char*                       title;
-    char                        appId[256];
+    char                        appId[256], windowTag[256];
 
     // We need to track the monitors the window spans on to calculate the
     // optimal scaling factor.
@@ -340,6 +341,7 @@ typedef struct _GLFWlibraryWayland
     struct xdg_activation_v1* xdg_activation_v1;
     struct xdg_toplevel_icon_manager_v1* xdg_toplevel_icon_manager_v1;
     struct xdg_system_bell_v1* xdg_system_bell_v1;
+    struct xdg_toplevel_tag_manager_v1* xdg_toplevel_tag_manager_v1;
     struct wp_cursor_shape_manager_v1* wp_cursor_shape_manager_v1;
     struct wp_cursor_shape_device_v1* wp_cursor_shape_device_v1;
     struct wp_fractional_scale_manager_v1 *wp_fractional_scale_manager_v1;

glfw/wl_window.c

@@ -1198,8 +1198,10 @@ create_window_desktop_surface(_GLFWwindow* window)
         zxdg_toplevel_decoration_v1_add_listener(window->wl.xdg.decoration, &xdgDecorationListener, window);
     }
 
-    if (strlen(window->wl.appId))
+    if (window->wl.appId[0])
         xdg_toplevel_set_app_id(window->wl.xdg.toplevel, window->wl.appId);
+    if (window->wl.windowTag[0] && _glfw.wl.xdg_toplevel_tag_manager_v1)
+        xdg_toplevel_tag_manager_v1_set_toplevel_tag(_glfw.wl.xdg_toplevel_tag_manager_v1, window->wl.xdg.toplevel, window->wl.windowTag);
 
     if (window->wl.title)
         xdg_toplevel_set_title(window->wl.xdg.toplevel, window->wl.title);

kitty/simple_cli_definitions.py

@@ -375,13 +375,13 @@ def kitty_options_spec() -> str:
 dest=cls
 default={appname}
 condition=not is_macos
-Set the class part of the :italic:`WM_CLASS` window property. On Wayland, it
-sets the app id.
+Set the :italic:`application id` on Wayland. On X11 set the class part of the :italic:`WM_CLASS` window property.
 
 
---name
+--name --os-window-tag
 condition=not is_macos
-Set the name part of the :italic:`WM_CLASS` property. Defaults to using the
+On Wayland, set the :italic:`window tag`.
+On X11, set the name part of the :italic:`WM_CLASS` property, when unset, defaults to using the
 value from :option:`{appname} --class`.
 
 
@@ -650,12 +650,13 @@ Use the special value :code:`list` to get a list of available outputs.
 dest=cls
 default={cls}
 condition=not is_macos
-Set the class part of the :italic:`WM_CLASS` window property. On Wayland, it sets the app id.
+Set the :italic:`application id` on Wayland. On X11 set the class part of the :italic:`WM_CLASS` window property.
 
 
---name
+--name --os-window-tag
 condition=not is_macos
-Set the name part of the :italic:`WM_CLASS` property (defaults to using the value from :option:`{appname} --class`)
+On X11 sets the name part of the :italic:`WM_CLASS` property on X11,
+when unspecified uses the value from :option:`{appname} --class` on X11.
 
 
 --focus-policy