GHOST/wayland: get cursor settings via D-Bus

build_files/cmake/platform/platform_unix.cmake

@@ -575,6 +575,7 @@ if(WITH_GHOST_WAYLAND)
   pkg_check_modules(wayland-scanner REQUIRED wayland-scanner)
   pkg_check_modules(xkbcommon REQUIRED xkbcommon)
   pkg_check_modules(wayland-cursor REQUIRED wayland-cursor)
+  pkg_check_modules(dbus REQUIRED dbus-1)
 
   set(WITH_GL_EGL ON)
 
@@ -583,6 +584,7 @@ if(WITH_GHOST_WAYLAND)
     ${wayland-egl_LINK_LIBRARIES}
     ${xkbcommon_LINK_LIBRARIES}
     ${wayland-cursor_LINK_LIBRARIES}
+    ${dbus_LINK_LIBRARIES}
   )
 endif()
 

intern/ghost/CMakeLists.txt

@@ -282,6 +282,7 @@ elseif(WITH_GHOST_X11 OR WITH_GHOST_WAYLAND)
       ${wayland-egl_INCLUDE_DIRS}
       ${xkbcommon_INCLUDE_DIRS}
       ${wayland-cursor_INCLUDE_DIRS}
+      ${dbus_INCLUDE_DIRS}
     )
 
     list(APPEND SRC

intern/ghost/intern/GHOST_SystemWayland.cpp

@@ -40,6 +40,7 @@
 #include <unordered_map>
 #include <unordered_set>
 
+#include "GHOST_WaylandCursorSettings.h"
 #include <pointer-constraints-client-protocol.h>
 #include <relative-pointer-client-protocol.h>
 #include <wayland-cursor.h>
@@ -1336,11 +1337,14 @@ GHOST_SystemWayland::GHOST_SystemWayland() : GHOST_System(), d(new display_t)
     }
   }
 
-  const char *theme = std::getenv("XCURSOR_THEME");
-  const char *size = std::getenv("XCURSOR_SIZE");
-  const int sizei = size ? std::stoi(size) : default_cursor_size;
+  std::string theme;
+  int size;
+  if (!get_cursor_settings(theme, size)) {
+    theme = std::string();
+    size = default_cursor_size;
+  }
 
-  d->cursor_theme = wl_cursor_theme_load(theme, sizei, d->shm);
+  d->cursor_theme = wl_cursor_theme_load(theme.c_str(), size, d->shm);
   if (!d->cursor_theme) {
     display_destroy(d);
     throw std::runtime_error("Wayland: unable to access cursor themes!");

intern/ghost/intern/GHOST_WaylandCursorSettings.h

@@ -0,0 +1,130 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup GHOST
+ */
+
+#pragma once
+#include <dbus/dbus.h>
+#include <string>
+
+static DBusMessage *get_setting_sync(DBusConnection *const connection,
+                                     const char *key,
+                                     const char *value)
+{
+  DBusError error;
+  dbus_bool_t success;
+  DBusMessage *message;
+  DBusMessage *reply;
+
+  dbus_error_init(&error);
+
+  message = dbus_message_new_method_call("org.freedesktop.portal.Desktop",
+                                         "/org/freedesktop/portal/desktop",
+                                         "org.freedesktop.portal.Settings",
+                                         "Read");
+
+  success = dbus_message_append_args(
+      message, DBUS_TYPE_STRING, &key, DBUS_TYPE_STRING, &value, DBUS_TYPE_INVALID);
+
+  if (!success) {
+    return NULL;
+  }
+
+  reply = dbus_connection_send_with_reply_and_block(
+      connection, message, DBUS_TIMEOUT_USE_DEFAULT, &error);
+
+  dbus_message_unref(message);
+
+  if (dbus_error_is_set(&error)) {
+    return NULL;
+  }
+
+  return reply;
+}
+
+static bool parse_type(DBusMessage *const reply, const int type, void *value)
+{
+  DBusMessageIter iter[3];
+
+  dbus_message_iter_init(reply, &iter[0]);
+  if (dbus_message_iter_get_arg_type(&iter[0]) != DBUS_TYPE_VARIANT) {
+    return false;
+  }
+
+  dbus_message_iter_recurse(&iter[0], &iter[1]);
+  if (dbus_message_iter_get_arg_type(&iter[1]) != DBUS_TYPE_VARIANT) {
+    return false;
+  }
+
+  dbus_message_iter_recurse(&iter[1], &iter[2]);
+  if (dbus_message_iter_get_arg_type(&iter[2]) != type) {
+    return false;
+  }
+
+  dbus_message_iter_get_basic(&iter[2], value);
+
+  return true;
+}
+
+static bool get_cursor_settings(std::string &theme, int &size)
+{
+  static const char name[] = "org.gnome.desktop.interface";
+  static const char key_theme[] = "cursor-theme";
+  static const char key_size[] = "cursor-size";
+
+  DBusError error;
+  DBusConnection *connection;
+  DBusMessage *reply;
+  const char *value_theme = NULL;
+
+  dbus_error_init(&error);
+
+  connection = dbus_bus_get(DBUS_BUS_SESSION, &error);
+
+  if (dbus_error_is_set(&error)) {
+    return false;
+  }
+
+  reply = get_setting_sync(connection, name, key_theme);
+  if (!reply) {
+    return false;
+  }
+
+  if (!parse_type(reply, DBUS_TYPE_STRING, &value_theme)) {
+    dbus_message_unref(reply);
+    return false;
+  }
+
+  theme = std::string(value_theme);
+
+  dbus_message_unref(reply);
+
+  reply = get_setting_sync(connection, name, key_size);
+  if (!reply) {
+    return false;
+  }
+
+  if (!parse_type(reply, DBUS_TYPE_INT32, &size)) {
+    dbus_message_unref(reply);
+    return false;
+  }
+
+  dbus_message_unref(reply);
+
+  return true;
+}