types/wlr_tablet_pad: add base wlr_input_device

wlr_tablet_pad owns its wlr_input_device. It will be initialized when the
tablet pad is initialized, and finished when the tablet pad is destroyed.

backend/libinput/tablet_pad.c

@@ -75,7 +75,10 @@ struct wlr_tablet_pad *create_libinput_tablet_pad(
 		wlr_log(WLR_ERROR, "Unable to allocate wlr_tablet_pad");
 		return NULL;
 	}
-	wlr_tablet_pad_init(wlr_tablet_pad, NULL);
+	const char *name = libinput_device_get_name(libinput_dev);
+	wlr_tablet_pad_init(wlr_tablet_pad, NULL, name);
+	wlr_tablet_pad->base.vendor = libinput_device_get_id_vendor(libinput_dev);
+	wlr_tablet_pad->base.product = libinput_device_get_id_product(libinput_dev);
 
 	wlr_tablet_pad->button_count =
 		libinput_device_tablet_pad_get_num_buttons(libinput_dev);

backend/wayland/tablet_v2.c

@@ -453,7 +453,7 @@ static void handle_pad_added(void *data,
 		zwp_tablet_pad_v2_destroy(id);
 		return;
 	}
-	wlr_tablet_pad_init(wlr_dev->tablet_pad, NULL);
+	wlr_tablet_pad_init(wlr_dev->tablet_pad, NULL, wlr_dev->name);
 	zwp_tablet_pad_v2_add_listener(id, &tablet_pad_listener, dev);
 }
 

include/wlr/interfaces/wlr_tablet_pad.h

@@ -16,7 +16,7 @@ struct wlr_tablet_pad_impl {
 };
 
 void wlr_tablet_pad_init(struct wlr_tablet_pad *pad,
-		struct wlr_tablet_pad_impl *impl);
+	struct wlr_tablet_pad_impl *impl, const char *name);
 void wlr_tablet_pad_destroy(struct wlr_tablet_pad *pad);
 
 #endif

include/wlr/types/wlr_tablet_pad.h

@@ -22,6 +22,8 @@
 struct wlr_tablet_pad_impl;
 
 struct wlr_tablet_pad {
+	struct wlr_input_device base;
+
 	struct wlr_tablet_pad_impl *impl;
 
 	struct {

types/wlr_tablet_pad.c

@@ -1,11 +1,15 @@
 #include <stdlib.h>
 #include <string.h>
 #include <wayland-server-core.h>
+#include <wlr/interfaces/wlr_input_device.h>
 #include <wlr/interfaces/wlr_tablet_pad.h>
 #include <wlr/types/wlr_tablet_pad.h>
 
 void wlr_tablet_pad_init(struct wlr_tablet_pad *pad,
-		struct wlr_tablet_pad_impl *impl) {
+		struct wlr_tablet_pad_impl *impl, const char *name) {
+	wlr_input_device_init(&pad->base, WLR_INPUT_DEVICE_TABLET_PAD, NULL, name);
+	pad->base.tablet_pad = pad;
+
 	pad->impl = impl;
 	wl_signal_init(&pad->events.button);
 	wl_signal_init(&pad->events.ring);
@@ -27,6 +31,7 @@ void wlr_tablet_pad_destroy(struct wlr_tablet_pad *pad) {
 	}
 	wl_array_release(&pad->paths);
 
+	wlr_input_device_finish(&pad->base);
 	if (pad->impl && pad->impl->destroy) {
 		pad->impl->destroy(pad);
 	} else {