Wayland: Implement key name support

README.md

@@ -266,6 +266,7 @@ information on what to include when reporting a bug.
    undefined behavior (#1986)
  - [X11] Bugfix: Dynamic loading on OpenBSD failed due to soname differences
  - [Wayland] Added dynamic loading of all Wayland libraries
+ - [Wayland] Added support for key names via xkbcommon
  - [Wayland] Removed support for `wl_shell` (#1443)
  - [Wayland] Bugfix: The `GLFW_HAND_CURSOR` shape used the wrong image (#1432)
  - [Wayland] Bugfix: `CLOCK_MONOTONIC` was not correctly enabled

src/wl_init.c

@@ -1290,6 +1290,8 @@ int _glfwInitWayland(void)
         _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_keymap_mod_get_index");
     _glfw.wl.xkb.keymap_key_repeats = (PFN_xkb_keymap_key_repeats)
         _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_keymap_key_repeats");
+    _glfw.wl.xkb.keymap_key_get_syms_by_level = (PFN_xkb_keymap_key_get_syms_by_level)
+        _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_keymap_key_get_syms_by_level");
     _glfw.wl.xkb.state_new = (PFN_xkb_state_new)
         _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_state_new");
     _glfw.wl.xkb.state_unref = (PFN_xkb_state_unref)
@@ -1300,6 +1302,8 @@ int _glfwInitWayland(void)
         _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_state_update_mask");
     _glfw.wl.xkb.state_serialize_mods = (PFN_xkb_state_serialize_mods)
         _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_state_serialize_mods");
+    _glfw.wl.xkb.state_key_get_layout = (PFN_xkb_state_key_get_layout)
+        _glfwPlatformGetModuleSymbol(_glfw.wl.xkb.handle, "xkb_state_key_get_layout");
 
 #ifdef HAVE_XKBCOMMON_COMPOSE_H
     _glfw.wl.xkb.compose_table_new_from_locale = (PFN_xkb_compose_table_new_from_locale)

src/wl_platform.h

@@ -163,22 +163,26 @@ typedef struct xkb_keymap* (* PFN_xkb_keymap_new_from_string)(struct xkb_context
 typedef void (* PFN_xkb_keymap_unref)(struct xkb_keymap*);
 typedef xkb_mod_index_t (* PFN_xkb_keymap_mod_get_index)(struct xkb_keymap*, const char*);
 typedef int (* PFN_xkb_keymap_key_repeats)(struct xkb_keymap*, xkb_keycode_t);
+typedef int (* PFN_xkb_keymap_key_get_syms_by_level)(struct xkb_keymap*,xkb_keycode_t,xkb_layout_index_t,xkb_level_index_t,const xkb_keysym_t**);
 typedef struct xkb_state* (* PFN_xkb_state_new)(struct xkb_keymap*);
 typedef void (* PFN_xkb_state_unref)(struct xkb_state*);
 typedef int (* PFN_xkb_state_key_get_syms)(struct xkb_state*, xkb_keycode_t, const xkb_keysym_t**);
 typedef enum xkb_state_component (* PFN_xkb_state_update_mask)(struct xkb_state*, xkb_mod_mask_t, xkb_mod_mask_t, xkb_mod_mask_t, xkb_layout_index_t, xkb_layout_index_t, xkb_layout_index_t);
 typedef xkb_mod_mask_t (* PFN_xkb_state_serialize_mods)(struct xkb_state*, enum xkb_state_component);
+typedef xkb_layout_index_t (* PFN_xkb_state_key_get_layout)(struct xkb_state*,xkb_keycode_t);
 #define xkb_context_new _glfw.wl.xkb.context_new
 #define xkb_context_unref _glfw.wl.xkb.context_unref
 #define xkb_keymap_new_from_string _glfw.wl.xkb.keymap_new_from_string
 #define xkb_keymap_unref _glfw.wl.xkb.keymap_unref
 #define xkb_keymap_mod_get_index _glfw.wl.xkb.keymap_mod_get_index
 #define xkb_keymap_key_repeats _glfw.wl.xkb.keymap_key_repeats
+#define xkb_keymap_key_get_syms_by_level _glfw.wl.xkb.keymap_key_get_syms_by_level
 #define xkb_state_new _glfw.wl.xkb.state_new
 #define xkb_state_unref _glfw.wl.xkb.state_unref
 #define xkb_state_key_get_syms _glfw.wl.xkb.state_key_get_syms
 #define xkb_state_update_mask _glfw.wl.xkb.state_update_mask
 #define xkb_state_serialize_mods _glfw.wl.xkb.state_serialize_mods
+#define xkb_state_key_get_layout _glfw.wl.xkb.state_key_get_layout
 
 #ifdef HAVE_XKBCOMMON_COMPOSE_H
 typedef struct xkb_compose_table* (* PFN_xkb_compose_table_new_from_locale)(struct xkb_context*, const char*, enum xkb_compose_compile_flags);
@@ -311,6 +315,7 @@ typedef struct _GLFWlibraryWayland
     int                         timerfd;
     short int                   keycodes[256];
     short int                   scancodes[GLFW_KEY_LAST + 1];
+    char                        keynames[GLFW_KEY_LAST + 1][5];
 
     struct {
         void*                   handle;
@@ -336,11 +341,13 @@ typedef struct _GLFWlibraryWayland
         PFN_xkb_keymap_unref keymap_unref;
         PFN_xkb_keymap_mod_get_index keymap_mod_get_index;
         PFN_xkb_keymap_key_repeats keymap_key_repeats;
+        PFN_xkb_keymap_key_get_syms_by_level keymap_key_get_syms_by_level;
         PFN_xkb_state_new state_new;
         PFN_xkb_state_unref state_unref;
         PFN_xkb_state_key_get_syms state_key_get_syms;
         PFN_xkb_state_update_mask state_update_mask;
         PFN_xkb_state_serialize_mods state_serialize_mods;
+        PFN_xkb_state_key_get_layout state_key_get_layout;
 
 #ifdef HAVE_XKBCOMMON_COMPOSE_H
         PFN_xkb_compose_table_new_from_locale compose_table_new_from_locale;

src/wl_window.c

@@ -1193,10 +1193,57 @@ void _glfwSetCursorModeWayland(_GLFWwindow* window, int mode)
 
 const char* _glfwGetScancodeNameWayland(int scancode)
 {
-    // TODO
-    _glfwInputError(GLFW_FEATURE_UNIMPLEMENTED,
-                    "Wayland: Key names not yet implemented");
-    return NULL;
+    if (scancode < 0 || scancode > 255 ||
+        _glfw.wl.keycodes[scancode] == GLFW_KEY_UNKNOWN)
+    {
+        _glfwInputError(GLFW_INVALID_VALUE,
+                        "Wayland: Invalid scancode %i",
+                        scancode);
+        return NULL;
+    }
+
+    const int key = _glfw.wl.keycodes[scancode];
+    const xkb_keycode_t keycode = scancode + 8;
+    const xkb_layout_index_t layout =
+        xkb_state_key_get_layout(_glfw.wl.xkb.state, keycode);
+    if (layout == XKB_LAYOUT_INVALID)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Wayland: Failed to retrieve layout for key name");
+        return NULL;
+    }
+
+    const xkb_keysym_t* keysyms = NULL;
+    xkb_keymap_key_get_syms_by_level(_glfw.wl.xkb.keymap,
+                                     keycode,
+                                     layout,
+                                     0,
+                                     &keysyms);
+    if (keysyms == NULL)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Wayland: Failed to retrieve keysym for key name");
+        return NULL;
+    }
+
+    const long codepoint = _glfwKeySym2Unicode(keysyms[0]);
+    if (codepoint == -1)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Wayland: Failed to retrieve codepoint for key name");
+        return NULL;
+    }
+
+    const size_t count = _glfwEncodeUTF8(_glfw.wl.keynames[key], (unsigned int) codepoint);
+    if (count == 0)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Wayland: Failed to encode codepoint for key name");
+        return NULL;
+    }
+
+    _glfw.wl.keynames[key][count] = '\0';
+    return _glfw.wl.keynames[key];
 }
 
 int _glfwGetKeyScancodeWayland(int key)