7 files changed, 35 insertions, 2 deletions
diff --git a/backend/drm/drm.c b/backend/drm/drm.c
index 1fceff95..06f012a3 100644
--- a/backend/drm/drm.c
+++ b/backend/drm/drm.c
@@ -658,6 +658,10 @@ static struct wlr_output_impl output_impl = {
 	.get_gamma_size = wlr_drm_connector_get_gamma_size,
 };
 
+bool wlr_output_is_drm(struct wlr_output *output) {
+	return output->impl == &output_impl;
+}
+
 static int retry_pageflip(void *data) {
 	struct wlr_drm_connector *conn = data;
 	wlr_log(L_INFO, "%s: Retrying pageflip", conn->output.name);
diff --git a/backend/headless/input_device.c b/backend/headless/input_device.c
index 05def775..5c62e87f 100644
--- a/backend/headless/input_device.c
+++ b/backend/headless/input_device.c
@@ -19,6 +19,10 @@ static struct wlr_input_device_impl input_device_impl = {
 	.destroy = input_device_destroy,
 };
 
+bool wlr_input_device_is_headless(struct wlr_input_device *wlr_dev) {
+	return wlr_dev->impl == &input_device_impl;
+}
+
 struct wlr_input_device *wlr_headless_add_input_device(
 		struct wlr_backend *wlr_backend, enum wlr_input_device_type type) {
 	struct wlr_headless_backend *backend =
diff --git a/backend/headless/output.c b/backend/headless/output.c
index 9c4ba35e..511c2c53 100644
--- a/backend/headless/output.c
+++ b/backend/headless/output.c
@@ -82,6 +82,10 @@ static const struct wlr_output_impl output_impl = {
 	.swap_buffers = output_swap_buffers,
 };
 
+bool wlr_output_is_headless(struct wlr_output *wlr_output) {
+	return wlr_output->impl == &output_impl;
+}
+
 static int signal_frame(void *data) {
 	struct wlr_headless_output *output = data;
 	wl_signal_emit(&output->wlr_output.events.frame, &output->wlr_output);
diff --git a/backend/libinput/events.c b/backend/libinput/events.c
index c14aef01..758a9f25 100644
--- a/backend/libinput/events.c
+++ b/backend/libinput/events.c
@@ -53,6 +53,10 @@ static struct wlr_input_device *allocate_device(
 	return wlr_dev;
 }
 
+bool wlr_input_device_is_libinput(struct wlr_input_device *wlr_dev) {
+        return wlr_dev->impl == &input_device_impl;
+}
+
 static void handle_device_added(struct wlr_libinput_backend *backend,
 		struct libinput_device *libinput_dev) {
 	assert(backend && libinput_dev);
diff --git a/backend/wayland/output.c b/backend/wayland/output.c
index d841ec49..d76f6366 100644
--- a/backend/wayland/output.c
+++ b/backend/wayland/output.c
@@ -205,6 +205,10 @@ static struct wlr_output_impl output_impl = {
 	.move_cursor = wlr_wl_output_move_cursor,
 };
 
+bool wlr_output_is_wl(struct wlr_output *wlr_output) {
+	return wlr_output->impl == &output_impl;
+}
+
 static void xdg_surface_handle_configure(void *data, struct zxdg_surface_v6 *xdg_surface,
 		uint32_t serial) {
 	struct wlr_wl_backend_output *output = data;
diff --git a/backend/wayland/wl_seat.c b/backend/wayland/wl_seat.c
index 0d4ebc8d..ddee268d 100644
--- a/backend/wayland/wl_seat.c
+++ b/backend/wayland/wl_seat.c
@@ -203,6 +203,10 @@ static struct wlr_input_device_impl input_device_impl = {
 	.destroy = input_device_destroy
 };
 
+bool wlr_input_device_is_wl(struct wlr_input_device *dev) {
+	return dev->impl == &input_device_impl;
+}
+
 static struct wlr_input_device *allocate_device(struct wlr_wl_backend *backend,
 		enum wlr_input_device_type type) {
 	struct wlr_wl_input_device *wlr_wl_dev;
diff --git a/backend/x11/backend.c b/backend/x11/backend.c
index f6f9cfa8..d2690342 100644
--- a/backend/x11/backend.c
+++ b/backend/x11/backend.c
@@ -25,6 +25,7 @@
 
 static struct wlr_backend_impl backend_impl;
 static struct wlr_output_impl output_impl;
+static struct wlr_input_device_impl input_device_impl = { 0 };
 
 static uint32_t xcb_button_to_wl(uint32_t button) {
 	switch (button) {
@@ -328,12 +329,12 @@ struct wlr_backend *wlr_x11_backend_create(struct wl_display *display,
 	}
 
 	wlr_input_device_init(&x11->keyboard_dev, WLR_INPUT_DEVICE_KEYBOARD,
-		NULL, "X11 keyboard", 0, 0);
+		&input_device_impl, "X11 keyboard", 0, 0);
 	wlr_keyboard_init(&x11->keyboard, NULL);
 	x11->keyboard_dev.keyboard = &x11->keyboard;
 
 	wlr_input_device_init(&x11->pointer_dev, WLR_INPUT_DEVICE_POINTER,
-		NULL, "X11 pointer", 0, 0);
+		&input_device_impl, "X11 pointer", 0, 0);
 	wlr_pointer_init(&x11->pointer, NULL);
 	x11->pointer_dev.pointer = &x11->pointer;
 
@@ -401,3 +402,11 @@ static struct wlr_output_impl output_impl = {
 	.make_current = output_make_current,
 	.swap_buffers = output_swap_buffers,
 };
+
+bool wlr_output_is_x11(struct wlr_output *wlr_output) {
+	return wlr_output->impl == &output_impl;
+}
+
+bool wlr_input_device_is_x11(struct wlr_input_device *wlr_dev) {
+	return wlr_dev->impl == &input_device_impl;
+}