1/*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20*/
21#include "SDL_internal.h"
22
23#include "SDL_dbus.h"
24#include "SDL_system_theme.h"
25#include "../../video/SDL_sysvideo.h"
26
27#include <unistd.h>
28
29#define PORTAL_DESTINATION "org.freedesktop.portal.Desktop"
30#define PORTAL_PATH "/org/freedesktop/portal/desktop"
31#define PORTAL_INTERFACE "org.freedesktop.portal.Settings"
32#define PORTAL_METHOD "Read"
33
34#define SIGNAL_INTERFACE "org.freedesktop.portal.Settings"
35#define SIGNAL_NAMESPACE "org.freedesktop.appearance"
36#define SIGNAL_NAME "SettingChanged"
37#define SIGNAL_KEY "color-scheme"
38
39typedef struct SystemThemeData
40{
41 SDL_DBusContext *dbus;
42 SDL_SystemTheme theme;
43} SystemThemeData;
44
45static SystemThemeData system_theme_data;
46
47static bool DBus_ExtractThemeVariant(DBusMessageIter *iter, SDL_SystemTheme *theme) {
48 SDL_DBusContext *dbus = system_theme_data.dbus;
49 Uint32 color_scheme;
50 DBusMessageIter variant_iter;
51
52 if (dbus->message_iter_get_arg_type(iter) != DBUS_TYPE_VARIANT)
53 return false;
54 dbus->message_iter_recurse(iter, &variant_iter);
55 if (dbus->message_iter_get_arg_type(&variant_iter) != DBUS_TYPE_UINT32)
56 return false;
57 dbus->message_iter_get_basic(&variant_iter, &color_scheme);
58 switch (color_scheme) {
59 case 0:
60 *theme = SDL_SYSTEM_THEME_UNKNOWN;
61 break;
62 case 1:
63 *theme = SDL_SYSTEM_THEME_DARK;
64 break;
65 case 2:
66 *theme = SDL_SYSTEM_THEME_LIGHT;
67 break;
68 }
69 return true;
70}
71
72static DBusHandlerResult DBus_MessageFilter(DBusConnection *conn, DBusMessage *msg, void *data) {
73 SDL_DBusContext *dbus = (SDL_DBusContext *)data;
74
75 if (dbus->message_is_signal(msg, SIGNAL_INTERFACE, SIGNAL_NAME)) {
76 DBusMessageIter signal_iter;
77 const char *namespace, *key;
78
79 dbus->message_iter_init(msg, &signal_iter);
80 // Check if the parameters are what we expect
81 if (dbus->message_iter_get_arg_type(&signal_iter) != DBUS_TYPE_STRING)
82 goto not_our_signal;
83 dbus->message_iter_get_basic(&signal_iter, &namespace);
84 if (SDL_strcmp(SIGNAL_NAMESPACE, namespace) != 0)
85 goto not_our_signal;
86
87 if (!dbus->message_iter_next(&signal_iter))
88 goto not_our_signal;
89
90 if (dbus->message_iter_get_arg_type(&signal_iter) != DBUS_TYPE_STRING)
91 goto not_our_signal;
92 dbus->message_iter_get_basic(&signal_iter, &key);
93 if (SDL_strcmp(SIGNAL_KEY, key) != 0)
94 goto not_our_signal;
95
96 if (!dbus->message_iter_next(&signal_iter))
97 goto not_our_signal;
98
99 if (!DBus_ExtractThemeVariant(&signal_iter, &system_theme_data.theme))
100 goto not_our_signal;
101
102 SDL_SetSystemTheme(system_theme_data.theme);
103 return DBUS_HANDLER_RESULT_HANDLED;
104 }
105not_our_signal:
106 return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
107}
108
109bool SDL_SystemTheme_Init(void)
110{
111 SDL_DBusContext *dbus = SDL_DBus_GetContext();
112 DBusMessage *msg;
113 static const char *namespace = SIGNAL_NAMESPACE;
114 static const char *key = SIGNAL_KEY;
115
116 system_theme_data.theme = SDL_SYSTEM_THEME_UNKNOWN;
117 system_theme_data.dbus = dbus;
118 if (!dbus) {
119 return false;
120 }
121
122 msg = dbus->message_new_method_call(PORTAL_DESTINATION, PORTAL_PATH, PORTAL_INTERFACE, PORTAL_METHOD);
123 if (msg) {
124 if (dbus->message_append_args(msg, DBUS_TYPE_STRING, &namespace, DBUS_TYPE_STRING, &key, DBUS_TYPE_INVALID)) {
125 DBusMessage *reply = dbus->connection_send_with_reply_and_block(dbus->session_conn, msg, 300, NULL);
126 if (reply) {
127 DBusMessageIter reply_iter, variant_outer_iter;
128
129 dbus->message_iter_init(reply, &reply_iter);
130 // The response has signature <<u>>
131 if (dbus->message_iter_get_arg_type(&reply_iter) != DBUS_TYPE_VARIANT)
132 goto incorrect_type;
133 dbus->message_iter_recurse(&reply_iter, &variant_outer_iter);
134 if (!DBus_ExtractThemeVariant(&variant_outer_iter, &system_theme_data.theme))
135 goto incorrect_type;
136incorrect_type:
137 dbus->message_unref(reply);
138 }
139 }
140 dbus->message_unref(msg);
141 }
142
143 dbus->bus_add_match(dbus->session_conn,
144 "type='signal', interface='"SIGNAL_INTERFACE"',"
145 "member='"SIGNAL_NAME"', arg0='"SIGNAL_NAMESPACE"',"
146 "arg1='"SIGNAL_KEY"'", NULL);
147 dbus->connection_add_filter(dbus->session_conn,
148 &DBus_MessageFilter, dbus, NULL);
149 dbus->connection_flush(dbus->session_conn);
150 return true;
151}
152
153SDL_SystemTheme SDL_SystemTheme_Get(void)
154{
155 return system_theme_data.theme;
156}
157