Hook up keyboard input callbacks

wayland.c

@@ -5,6 +5,7 @@
 #include <GL/gl.h>
 #include <string.h>
 #include <stdlib.h>
+#include <stdbool.h>
 // Generated header using wayland-scanner
 #include "xdg-shell-client-protocol.h"
 
@@ -15,8 +16,15 @@ struct xdg_wm_base *wm_base = NULL;
 struct xdg_surface *xdg_surface = NULL;
 struct xdg_toplevel *xdg_toplevel = NULL;
 struct wl_egl_window *window = NULL;
+/* Input API */
+struct wl_seat *wl_seat = NULL;
+struct wl_keyboard *wl_keyboard = NULL;
+struct wl_pointer *wl_pointer = NULL;
 EGLBoolean errcode = 0;
 
+/* Misc. global state */
+bool running = true;
+
 char *egl_s(int code)
 {
     switch (code)
@@ -37,7 +45,7 @@ char *egl_s(int code)
     }
 }
 
-void registry_handle_global([[maybe_unused]] void *data, struct wl_registry *registry,
+void registry_handle_global( void *data, struct wl_registry *registry,
 		uint32_t name, const char *interface, uint32_t version)
 {
     fprintf(stdout, "Wayland interface: '%s', version: %d, name: %d\n",
@@ -52,11 +60,16 @@ void registry_handle_global([[maybe_unused]] void *data, struct wl_registry *reg
         fprintf(stdout, "Registering XDG WM base interface...\n");
         wm_base = wl_registry_bind(registry, name, &xdg_wm_base_interface, 1);
     }
+    if (!strcmp(interface, wl_seat_interface.name))
+    {
+        fprintf(stdout, "Registering WL seat interface...\n");
+        wl_seat = wl_registry_bind(registry, name, &wl_seat_interface, 1);
+    }
 }
 
 
-void registry_handle_global_remove([[maybe_unused]]void *data, [[maybe_unused]]struct wl_registry *registry,
-		[[maybe_unused]]uint32_t name)
+void registry_handle_global_remove(void *data, struct wl_registry *registry,
+		uint32_t name)
 {
 	// This space deliberately left blank
 }
@@ -68,7 +81,7 @@ registry_listener = {
 };
 
 /* Window size change callbacks */
-static void xdg_toplevel_configure([[maybe_unused]] void *data, [[maybe_unused]] struct xdg_toplevel *t, int32_t width, int32_t height, [[maybe_unused]] struct wl_array *states)
+void xdg_toplevel_configure(void *data, struct xdg_toplevel *t, int32_t width, int32_t height, struct wl_array *states)
 {
     if (!width || !height)
       return; // compositor is deferring to us
@@ -78,6 +91,49 @@ static void xdg_toplevel_configure([[maybe_unused]] void *data, [[maybe_unused]]
     glViewport(0, 0, width, height);
 }
 
+/* Window close callback */
+void xdg_toplevel_close(void *data, struct xdg_toplevel *xdg_toplevel)
+{
+    running = false;
+}
+
+/* Basic wayland method to check if our program is responsive still */
+void wayland_ping(void *data, struct xdg_wm_base *base, uint32_t serial)
+{
+    xdg_wm_base_pong(base, serial);
+}
+
+void keymap_callback(void *data, struct wl_keyboard *kb, uint format, int fd, uint size)
+{
+    // TODO: Check for XKB compatibility and use xkbcommon to extract
+    fprintf(stdout, "KBMAP of size %d detected\n", size);
+}
+
+void enter_callback(void *data, struct wl_keyboard* kb, uint serial, struct wl_surface* surface, struct wl_array *keys)
+{
+    fprintf(stdout, "KBMAP with serial %d entered surface\n", serial);
+}
+
+void leave_callback(void *data, struct wl_keyboard* kb, uint serial, struct wl_surface* surface)
+{
+    fprintf(stdout, "KBMAP with serial %d left surface\n", serial);
+}
+
+void key_callback(void *data, struct wl_keyboard *kb, uint serial, uint time, uint key, uint state)
+{
+    fprintf(stdout, "Pressed key %d\n", key);
+}
+
+void modifier_callback(void *data, struct wl_keyboard *kb, uint serial, uint mods_depressed, uint mods_latched, uint mods_locked, uint group)
+{
+    fprintf(stdout, "Keyboard modifier keys changed\n");
+}
+
+void repeat_info_callback(void *data, struct wl_keyboard *kb, int rate, int delay)
+{
+    fprintf(stdout, "Keyboard repeat/delay rate changed\n");
+}
+
 int main()
 {
     fprintf(stdout, "Starting platform layer...\n");
@@ -110,10 +166,33 @@ int main()
     xdg_toplevel_set_title(xdg_toplevel, "Hi");
 
     const struct xdg_toplevel_listener xdg_toplevel_listener = {
-      .configure = xdg_toplevel_configure
+      .configure = xdg_toplevel_configure,
+      .close = xdg_toplevel_close
+    };
+    const struct xdg_wm_base_listener xdg_wm_base_listener = {
+      .ping = wayland_ping
     };
     if (xdg_toplevel_add_listener(xdg_toplevel, &xdg_toplevel_listener, NULL))
         fprintf(stderr, "Could not set XDG toplevel listener\n");
+    if (xdg_wm_base_add_listener(wm_base, &xdg_wm_base_listener, NULL))
+        fprintf(stderr, "Could not set XDG WM base listener\n");
+    if (!(wl_keyboard = wl_seat_get_keyboard(wl_seat)))
+        fprintf(stderr, "Could not get XKB keyboard\n");
+    if (!(wl_pointer = wl_seat_get_pointer(wl_seat)))
+        fprintf(stderr, "Could not get WL pointer\n");
+
+    /* NOTE: We have to define all available callbacks for the keyboard listener even if we are not interested in them:
+       https://gitlab.freedesktop.org/wayland/wayland/-/issues/160 */
+    const struct wl_keyboard_listener wl_keyboard_listener = {
+      .keymap = keymap_callback,
+      .enter = enter_callback,
+      .leave = leave_callback,
+      .key = key_callback,
+      .modifiers = modifier_callback,
+      .repeat_info = repeat_info_callback,
+    };
+    wl_keyboard_add_listener(wl_keyboard, &wl_keyboard_listener, NULL);
+      
 
     /* WL EGL initialization */
     window = wl_egl_window_create(surface, 480, 460);
@@ -159,7 +238,7 @@ int main()
         int attr;
 #define PRINT_ATTR(attr_name)                                                     \
         errcode = eglGetConfigAttrib(egl_display, configs[i], attr_name, &attr);  \
-        [[maybe_unused]] int attr_##attr_name = -1;                               \
+        int attr_##attr_name = -1;                                                \
         do {                                                                      \
             if (errcode == EGL_TRUE) {                                            \
                 fprintf(stdout, "\t\t" #attr_name ": %d (%#0x)\n", attr, attr);   \
@@ -263,7 +342,7 @@ int main()
     
     // Main event loop
     int framecount = 0;
-    while (1)
+    while (running)
     {
         wl_display_dispatch_pending(display);
         //fprintf(stdout, "Frame %d\n", framecount);