From 5d2f5946260a06caa5d5ca55a13726c99eb0c1f1 Mon Sep 17 00:00:00 2001
From: Consus <consus@ftml.net>
Date: Sat, 2 Dec 2023 17:56:32 +0300
Subject: [PATCH] Implement cursor-shape-v1 protocol

This protocol allows Wayland clients to request a buffer for a cursor
shape from a compositor.

Tested with foot.
---
 include/labwc.h       |  1 +
 protocols/meson.build |  1 +
 src/input/cursor.c    | 43 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 45 insertions(+)

diff --git a/include/labwc.h b/include/labwc.h
index f288de35..86198a03 100644
--- a/include/labwc.h
+++ b/include/labwc.h
@@ -175,6 +175,7 @@ struct seat {
 	struct wl_listener swipe_end;
 
 	struct wl_listener request_cursor;
+	struct wl_listener request_set_shape;
 	struct wl_listener request_set_selection;
 	struct wl_listener request_set_primary_selection;
 
diff --git a/protocols/meson.build b/protocols/meson.build
index d2f7fc7e..527f9d4c 100644
--- a/protocols/meson.build
+++ b/protocols/meson.build
@@ -16,6 +16,7 @@ wayland_scanner_server = generator(
 server_protocols = [
 	wl_protocol_dir / 'stable/xdg-shell/xdg-shell.xml',
 	wl_protocol_dir / 'unstable/pointer-constraints/pointer-constraints-unstable-v1.xml',
+	wl_protocol_dir / 'staging/cursor-shape/cursor-shape-v1.xml',
 	wl_protocol_dir / 'staging/drm-lease/drm-lease-v1.xml',
 	'wlr-layer-shell-unstable-v1.xml',
 	'wlr-input-inhibitor-unstable-v1.xml',
diff --git a/src/input/cursor.c b/src/input/cursor.c
index a98866dc..cb3f67bc 100644
--- a/src/input/cursor.c
+++ b/src/input/cursor.c
@@ -4,6 +4,7 @@
 #include <linux/input-event-codes.h>
 #include <sys/time.h>
 #include <time.h>
+#include <wlr/types/wlr_cursor_shape_v1.h>
 #include <wlr/types/wlr_primary_selection.h>
 #include <wlr/util/region.h>
 #include "action.h"
@@ -22,6 +23,8 @@
 #include "ssd.h"
 #include "view.h"
 
+#define LAB_CURSOR_SHAPE_V1_VERSION 1
+
 static const char * const *cursor_names = NULL;
 
 /* Usual cursor names */
@@ -158,6 +161,33 @@ request_cursor_notify(struct wl_listener *listener, void *data)
 	}
 }
 
+static void
+request_set_shape_notify(struct wl_listener *listener, void *data)
+{
+	struct wlr_cursor_shape_manager_v1_request_set_shape_event *event = data;
+	const char *shape_name = wlr_cursor_shape_v1_name(event->shape);
+	struct seat *seat = wl_container_of(listener, seat, request_set_shape);
+	struct wlr_seat_client *focused_client = seat->seat->pointer_state.focused_client;
+
+	/* Prevent setting a cursor image when moving or resizing */
+	if (seat->server->input_mode != LAB_INPUT_STATE_PASSTHROUGH) {
+		return;
+	}
+
+	/*
+	 * This can be sent by any client, so we check to make sure this one
+	 * actually has pointer focus first.
+	 */
+	if (event->seat_client != focused_client) {
+		wlr_log(WLR_INFO, "seat client %p != focused client %p",
+			event->seat_client, focused_client);
+		return;
+	}
+
+	wlr_log(WLR_DEBUG, "set xcursor to shape %s", shape_name);
+	wlr_cursor_set_xcursor(seat->cursor, seat->xcursor_manager, shape_name);
+}
+
 static void
 request_set_selection_notify(struct wl_listener *listener, void *data)
 {
@@ -1225,6 +1255,18 @@ cursor_init(struct seat *seat)
 	seat->request_cursor.notify = request_cursor_notify;
 	wl_signal_add(&seat->seat->events.request_set_cursor,
 		&seat->request_cursor);
+
+	struct wlr_cursor_shape_manager_v1 *cursor_shape_manager =
+		wlr_cursor_shape_manager_v1_create(seat->server->wl_display,
+			LAB_CURSOR_SHAPE_V1_VERSION);
+	if (!cursor_shape_manager) {
+		wlr_log(WLR_ERROR, "unable to create cursor_shape interface");
+		exit(EXIT_FAILURE);
+	}
+	seat->request_set_shape.notify = request_set_shape_notify;
+	wl_signal_add(&cursor_shape_manager->events.request_set_shape,
+		&seat->request_set_shape);
+
 	seat->request_set_selection.notify = request_set_selection_notify;
 	wl_signal_add(&seat->seat->events.request_set_selection,
 		&seat->request_set_selection);
@@ -1249,6 +1291,7 @@ void cursor_finish(struct seat *seat)
 	touch_finish(seat);
 
 	wl_list_remove(&seat->request_cursor.link);
+	wl_list_remove(&seat->request_set_shape.link);
 	wl_list_remove(&seat->request_set_selection.link);
 
 	wlr_xcursor_manager_destroy(seat->xcursor_manager);