Hook up mouse callbacks

Makefile

@@ -1,9 +1,9 @@
 INTERFACEDIR:=$(shell pkg-config --variable=pkgdatadir wayland-protocols)
 CFLAGS=-Wall -Wextra -Og -ggdb3 -Wno-unused-but-set-variable -Wno-unused-parameter
-LIBS=-lwayland-client -lwayland-egl -lEGL -lOpenGL
+LIBS=-lwayland-client -lwayland-egl -lEGL -lOpenGL -lxkbcommon
 wayland: wayland.c xdg-shell-protocol.c xdg-shell-client-protocol.h
 	gcc $(CFLAGS) $(LIBS) wayland.c xdg-shell-protocol.c -o wayland
-xdg-shell-protocol.c: 
+xdg-shell-protocol.c:
 	wayland-scanner private-code  $(INTERFACEDIR)/stable/xdg-shell/xdg-shell.xml xdg-shell-protocol.c
 xdg-shell-client-protocol.h:
-	wayland-scanner client-header $(INTERFACEDIR)/stable/xdg-shell/xdg-shell.xml xdg-shell-client-protocol.h 
+	wayland-scanner client-header $(INTERFACEDIR)/stable/xdg-shell/xdg-shell.xml xdg-shell-client-protocol.h

wayland.c

@@ -3,9 +3,12 @@
 #include <wayland-egl.h>
 #include <EGL/egl.h>
 #include <GL/gl.h>
+#include <xkbcommon/xkbcommon.h>
 #include <string.h>
 #include <stdlib.h>
 #include <stdbool.h>
+#include <sys/mman.h>
+#include <unistd.h>
 // Generated header using wayland-scanner
 #include "xdg-shell-client-protocol.h"
 
@@ -16,13 +19,19 @@ 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;
+
+/* XKB library */
+struct xkb_context *xkb_context = NULL;
+struct xkb_state *xkb_state = NULL;
+struct xkb_keymap *xkb_keymap = NULL;
 
 /* Misc. global state */
+EGLBoolean errcode = 0;
 bool running = true;
 
 char *egl_s(int code)
@@ -60,14 +69,15 @@ void registry_handle_global( void *data, struct wl_registry *registry,
         fprintf(stdout, "Registering XDG WM base interface...\n");
         wm_base = wl_registry_bind(registry, name, &xdg_wm_base_interface, 1);
     }
+    /* NOTE: Since wl_seat v5, pointer events are grouped into "frames", which do not appear to be useful for non-touch applications and
+             also create more events which are more complicated to dispatch. */
     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);
+        wl_seat = wl_registry_bind(registry, name, &wl_seat_interface, 9);
     }
 }
 
-
 void registry_handle_global_remove(void *data, struct wl_registry *registry,
 		uint32_t name)
 {
@@ -103,10 +113,24 @@ void wayland_ping(void *data, struct xdg_wm_base *base, uint32_t serial)
     xdg_wm_base_pong(base, serial);
 }
 
+void wl_seat_capabilities_callback(void *data, struct wl_seat *wl_seat, uint capabilities)
+{
+    fprintf(stdout, "Capabilities changed for WL seat\n");
+}
+
 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);
+
+    char *mem = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
+    fprintf(stdout, "XKBMAP desc:\n\t%s\n", mem);
+    xkb_keymap = xkb_keymap_new_from_string(xkb_context, mem, XKB_KEYMAP_FORMAT_TEXT_V1, XKB_KEYMAP_COMPILE_NO_FLAGS);
+    munmap(mem, size);
+    close(fd);
+    
+    if (!(xkb_state = xkb_state_new(xkb_keymap)))
+        fprintf(stderr, "Could not initialize XKB state machine\n");
 }
 
 void enter_callback(void *data, struct wl_keyboard* kb, uint serial, struct wl_surface* surface, struct wl_array *keys)
@@ -121,12 +145,27 @@ void leave_callback(void *data, struct wl_keyboard* kb, uint serial, struct wl_s
 
 void key_callback(void *data, struct wl_keyboard *kb, uint serial, uint time, uint key, uint state)
 {
-    fprintf(stdout, "Pressed key %d\n", key);
+    /* TODO: This does *not* respect the system's language defaults. At least not in KDE.
+     *       Wayland's own (terrible) documentation does not go into detail about languages:
+     *       https://wayland-book.com/seat/xkb.html
+     */
+    key += 8;
+    uint32_t layout = xkb_state_key_get_layout(xkb_state, key);
+    if (layout >= xkb_keymap_num_layouts_for_key(xkb_keymap, key))
+        fprintf(stderr, "Layout %d exceeds number of available key layouts\n", layout);
+
+    xkb_keysym_t sym = xkb_state_key_get_one_sym(xkb_state, key);
+    char keyname[128];
+    xkb_keysym_get_name(sym, keyname, sizeof(keyname));
+    char keyutf8[128];
+    xkb_state_key_get_utf8(xkb_state, key, keyutf8, sizeof(keyutf8));
+    fprintf(stdout, "%s key %d layout %d (KEYSYM %s) (UTF8 %s)\n", (state == WL_KEYBOARD_KEY_STATE_PRESSED ? "Pressed" : "Released"), key, layout, keyname, keyutf8);
 }
 
 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");
+    xkb_state_update_mask(xkb_state, mods_depressed, mods_latched, mods_locked, 0, 0, group);
 }
 
 void repeat_info_callback(void *data, struct wl_keyboard *kb, int rate, int delay)
@@ -134,6 +173,56 @@ void repeat_info_callback(void *data, struct wl_keyboard *kb, int rate, int dela
     fprintf(stdout, "Keyboard repeat/delay rate changed\n");
 }
 
+void pointer_enter_callback(void *data, struct wl_pointer *pointer, uint serial, struct wl_surface *surface, wl_fixed_t x, wl_fixed_t y)
+{
+    fprintf(stdout, "Pointer entered WL surface on coordinates %d %d\n", x, y);
+}
+
+void pointer_leave_callback(void *data, struct wl_pointer *pointer, uint serial, struct wl_surface *surface)
+{
+    fprintf(stdout, "Pointer left WL surface\n");
+}
+
+void pointer_motion_callback(void *data, struct wl_pointer *pointer, uint time, wl_fixed_t x, wl_fixed_t y)
+{
+    fprintf(stdout, "Pointer moved to %d %d\n", x, y);
+}
+
+void pointer_button_callback(void *data, struct wl_pointer *pointer, uint serial, uint time, uint button, uint state)
+{
+    fprintf(stdout, "Pointer button %d changed state\n", button);
+}
+
+void pointer_axis_callback(void *data, struct wl_pointer *pointer, uint time, uint axis, wl_fixed_t value)
+{
+    fprintf(stdout, "Pointer scroll on axis %d value %d\n", axis, value);
+}
+
+/* NOTE: *some* events are logically grouped together. The frame event marks the boundary between groups of them. More info: https://wayland.freedesktop.org/docs/html/apa.html#protocol-spec-wl_pointer */
+
+void pointer_frame_callback(void *data, struct wl_pointer *frame)
+{
+    fprintf(stdout, "Pointer frame ended\n");
+}
+
+/* NOTE: This event is also used to group pointer events together. It specifies info about all events in its frame */
+void pointer_axis_source_callback(void *data, struct wl_pointer *pointer, uint axis_source)
+{
+    fprintf(stdout, "Pointer axis source: %d\n", axis_source);
+}
+
+/* Optional event to implement kinetic scrolling */
+void pointer_axis_stop_callback(void *data, struct wl_pointer *pointer, uint time, uint axis)
+{
+    fprintf(stdout, "Pointer axis stopped: %d\n", axis);
+}
+
+/* Optional event. Carries discrete scroll info after an 'axis' event */
+void pointer_axis_discrete_callback(void *data, struct wl_pointer *pointer, uint axis, int discrete)
+{
+    fprintf(stdout, "Pointer axis discrete step: %d\n", discrete);
+}
+
 int main()
 {
     fprintf(stdout, "Starting platform layer...\n");
@@ -165,13 +254,19 @@ int main()
     xdg_toplevel = xdg_surface_get_toplevel(xdg_surface);
     xdg_toplevel_set_title(xdg_toplevel, "Hi");
 
+    /* XKB library initialization */
+    xkb_context = xkb_context_new(XKB_CONTEXT_NO_FLAGS);
+
+
     const struct xdg_toplevel_listener xdg_toplevel_listener = {
       .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))
@@ -181,6 +276,13 @@ int main()
     if (!(wl_pointer = wl_seat_get_pointer(wl_seat)))
         fprintf(stderr, "Could not get WL pointer\n");
 
+    const struct wl_seat_listener wl_seat_listener = {
+        .capabilities = wl_seat_capabilities_callback
+    };
+
+    if (wl_seat_add_listener(wl_seat, &wl_seat_listener, NULL))
+        fprintf(stderr, "Could not set WL seat listener\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 = {
@@ -191,8 +293,24 @@ int main()
       .modifiers = modifier_callback,
       .repeat_info = repeat_info_callback,
     };
-    wl_keyboard_add_listener(wl_keyboard, &wl_keyboard_listener, NULL);
+    if (wl_keyboard_add_listener(wl_keyboard, &wl_keyboard_listener, NULL))
-      
+        fprintf(stderr, "Could not set XKB keyboard listener\n");
+    
+    // TODO: Apparently we are not setting opcode 10's callback?
+    const struct wl_pointer_listener wl_pointer_listener = {
+        .enter = pointer_enter_callback,
+        .leave = pointer_leave_callback,
+        .motion = pointer_motion_callback,
+        .button = pointer_button_callback,
+        .axis = pointer_axis_callback,
+        .frame = pointer_frame_callback,
+        .axis_source = pointer_axis_source_callback,
+        .axis_stop = pointer_axis_stop_callback,
+        .axis_discrete = pointer_axis_discrete_callback
+    };
+
+    if (wl_pointer_add_listener(wl_pointer, &wl_pointer_listener, NULL))
+        fprintf(stderr, "Could not set WL pointer listener\n");
 
     /* WL EGL initialization */
     window = wl_egl_window_create(surface, 480, 460);
@@ -339,7 +457,7 @@ int main()
 
     // necessary before our first eglSwapBuffers
     wl_surface_commit(surface);
-    
+
     // Main event loop
     int framecount = 0;
     while (running)