1/* GDK - The GIMP Drawing Kit
2 * Copyright (C) 2000 Red Hat, Inc.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18/*
19 * Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
20 * file for a list of people on the GTK+ Team. See the ChangeLog
21 * files for a list of changes. These files are distributed with
22 * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
23 */
24
25#include "config.h"
26
27#include "gdkconfig.h"
28#include "gdkdisplaymanagerprivate.h"
29#include "gdkdisplayprivate.h"
30#include "gdkkeysprivate.h"
31#include "gdkintl.h"
32
33#ifdef GDK_WINDOWING_X11
34#include "x11/gdkx.h"
35#include "x11/gdkprivate-x11.h"
36#endif
37
38#ifdef GDK_WINDOWING_BROADWAY
39#include "broadway/gdkprivate-broadway.h"
40#endif
41
42#ifdef GDK_WINDOWING_MACOS
43#include "macos/gdkmacosdisplay-private.h"
44#endif
45
46#ifdef GDK_WINDOWING_WIN32
47#include "win32/gdkwin32.h"
48#include "win32/gdkprivate-win32.h"
49#endif
50
51#ifdef GDK_WINDOWING_WAYLAND
52#include "wayland/gdkprivate-wayland.h"
53#endif
54
55/**
56 * GdkDisplayManager:
57 *
58 * A singleton object that offers notification when displays appear or
59 * disappear.
60 *
61 * You can use [func@Gdk.DisplayManager.get] to obtain the `GdkDisplayManager`
62 * singleton, but that should be rarely necessary. Typically, initializing
63 * GTK opens a display that you can work with without ever accessing the
64 * `GdkDisplayManager`.
65 *
66 * The GDK library can be built with support for multiple backends.
67 * The `GdkDisplayManager` object determines which backend is used
68 * at runtime.
69 *
70 * In the rare case that you need to influence which of the backends
71 * is being used, you can use [func@Gdk.set_allowed_backends]. Note
72 * that you need to call this function before initializing GTK.
73 *
74 * ## Backend-specific code
75 *
76 * When writing backend-specific code that is supposed to work with
77 * multiple GDK backends, you have to consider both compile time and
78 * runtime. At compile time, use the `GDK_WINDOWING_X11`, `GDK_WINDOWING_WIN32`
79 * macros, etc. to find out which backends are present in the GDK library
80 * you are building your application against. At runtime, use type-check
81 * macros like GDK_IS_X11_DISPLAY() to find out which backend is in use:
82 *
83 * ```c
84 * #ifdef GDK_WINDOWING_X11
85 * if (GDK_IS_X11_DISPLAY (display))
86 * {
87 * // make X11-specific calls here
88 * }
89 * else
90 * #endif
91 * #ifdef GDK_WINDOWING_MACOS
92 * if (GDK_IS_MACOS_DISPLAY (display))
93 * {
94 * // make Quartz-specific calls here
95* }
96 * else
97 * #endif
98 * g_error ("Unsupported GDK backend");
99 * ```
100 */
101
102enum {
103 PROP_0,
104 PROP_DEFAULT_DISPLAY
105};
106
107enum {
108 DISPLAY_OPENED,
109 LAST_SIGNAL
110};
111
112static void gdk_display_manager_set_property (GObject *object,
113 guint prop_id,
114 const GValue *value,
115 GParamSpec *pspec);
116static void gdk_display_manager_get_property (GObject *object,
117 guint prop_id,
118 GValue *value,
119 GParamSpec *pspec);
120
121static guint signals[LAST_SIGNAL] = { 0 };
122
123G_DEFINE_TYPE (GdkDisplayManager, gdk_display_manager, G_TYPE_OBJECT)
124
125static void
126gdk_display_manager_class_init (GdkDisplayManagerClass *klass)
127{
128 GObjectClass *object_class = G_OBJECT_CLASS (klass);
129
130 object_class->set_property = gdk_display_manager_set_property;
131 object_class->get_property = gdk_display_manager_get_property;
132
133 /**
134 * GdkDisplayManager::display-opened:
135 * @manager: the object on which the signal is emitted
136 * @display: the opened display
137 *
138 * Emitted when a display is opened.
139 */
140 signals[DISPLAY_OPENED] =
141 g_signal_new (signal_name: g_intern_static_string (string: "display-opened"),
142 G_OBJECT_CLASS_TYPE (object_class),
143 signal_flags: G_SIGNAL_RUN_LAST,
144 G_STRUCT_OFFSET (GdkDisplayManagerClass, display_opened),
145 NULL, NULL,
146 NULL,
147 G_TYPE_NONE,
148 n_params: 1,
149 GDK_TYPE_DISPLAY);
150
151 /**
152 * GdkDisplayManager:default-display: (attributes org.gtk.Property.get=gdk_display_manager_get_default_display)
153 *
154 * The default display.
155 */
156 g_object_class_install_property (oclass: object_class,
157 property_id: PROP_DEFAULT_DISPLAY,
158 pspec: g_param_spec_object (name: "default-display",
159 P_("Default Display"),
160 P_("The default display for GDK"),
161 GDK_TYPE_DISPLAY,
162 flags: G_PARAM_READWRITE|G_PARAM_STATIC_STRINGS));
163}
164
165static void
166gdk_display_manager_init (GdkDisplayManager *manager)
167{
168}
169
170static void
171gdk_display_manager_set_property (GObject *object,
172 guint prop_id,
173 const GValue *value,
174 GParamSpec *pspec)
175{
176 switch (prop_id)
177 {
178 case PROP_DEFAULT_DISPLAY:
179 gdk_display_manager_set_default_display (GDK_DISPLAY_MANAGER (object),
180 display: g_value_get_object (value));
181 break;
182 default:
183 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
184 break;
185 }
186}
187
188static void
189gdk_display_manager_get_property (GObject *object,
190 guint prop_id,
191 GValue *value,
192 GParamSpec *pspec)
193{
194 switch (prop_id)
195 {
196 case PROP_DEFAULT_DISPLAY:
197 g_value_set_object (value,
198 v_object: gdk_display_manager_get_default_display (GDK_DISPLAY_MANAGER (object)));
199 break;
200 default:
201 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
202 break;
203 }
204}
205
206static const char *allowed_backends;
207
208/**
209 * gdk_set_allowed_backends:
210 * @backends: a comma-separated list of backends
211 *
212 * Sets a list of backends that GDK should try to use.
213 *
214 * This can be useful if your application does not
215 * work with certain GDK backends.
216 *
217 * By default, GDK tries all included backends.
218 *
219 * For example:
220 *
221 * ```c
222 * gdk_set_allowed_backends ("wayland,macos,*");
223 * ```
224 *
225 * instructs GDK to try the Wayland backend first, followed by the
226 * MacOs backend, and then all others.
227 *
228 * If the `GDK_BACKEND` environment variable is set, it determines
229 * what backends are tried in what order, while still respecting the
230 * set of allowed backends that are specified by this function.
231 *
232 * The possible backend names are:
233 *
234 * - `broadway`
235 * - `macos`
236 * - `wayland`.
237 * - `win32`
238 * - `x11`
239 *
240 * You can also include a `*` in the list to try all remaining backends.
241 *
242 * This call must happen prior to functions that open a display, such
243 * as [func@Gdk.Display.open], `gtk_init()`, or `gtk_init_check()`
244 * in order to take effect.
245 */
246void
247gdk_set_allowed_backends (const char *backends)
248{
249 allowed_backends = g_strdup (str: backends);
250}
251
252typedef struct _GdkBackend GdkBackend;
253
254struct _GdkBackend {
255 const char *name;
256 GdkDisplay * (* open_display) (const char *name);
257};
258
259static GdkBackend gdk_backends[] = {
260#ifdef GDK_WINDOWING_MACOS
261 { "macos", _gdk_macos_display_open },
262#endif
263#ifdef GDK_WINDOWING_WIN32
264 { "win32", _gdk_win32_display_open },
265#endif
266#ifdef GDK_WINDOWING_WAYLAND
267 { "wayland", _gdk_wayland_display_open },
268#endif
269#ifdef GDK_WINDOWING_X11
270 { "x11", gdk_x11_display_open },
271#endif
272#ifdef GDK_WINDOWING_BROADWAY
273 { "broadway", _gdk_broadway_display_open },
274#endif
275 /* NULL-terminating this array so we can use commas above */
276 { NULL, NULL }
277};
278
279/**
280 * gdk_display_manager_get:
281 *
282 * Gets the singleton `GdkDisplayManager` object.
283 *
284 * When called for the first time, this function consults the
285 * `GDK_BACKEND` environment variable to find out which of the
286 * supported GDK backends to use (in case GDK has been compiled
287 * with multiple backends).
288 *
289 * Applications can use [func@set_allowed_backends] to limit what
290 * backends wil be used.
291 *
292 * Returns: (transfer none): The global `GdkDisplayManager` singleton
293 */
294GdkDisplayManager*
295gdk_display_manager_get (void)
296{
297 static GdkDisplayManager *manager = NULL;
298
299 if (manager == NULL)
300 manager = g_object_new (GDK_TYPE_DISPLAY_MANAGER, NULL);
301
302 return manager;
303}
304
305/**
306 * gdk_display_manager_get_default_display: (attributes org.gtk.Method.get_property=default-display)
307 * @manager: a `GdkDisplayManager`
308 *
309 * Gets the default `GdkDisplay`.
310 *
311 * Returns: (nullable) (transfer none): a `GdkDisplay`
312 */
313GdkDisplay *
314gdk_display_manager_get_default_display (GdkDisplayManager *manager)
315{
316 return manager->default_display;
317}
318
319/**
320 * gdk_display_get_default:
321 *
322 * Gets the default `GdkDisplay`.
323 *
324 * This is a convenience function for:
325 *
326 * gdk_display_manager_get_default_display (gdk_display_manager_get ())
327 *
328 * Returns: (nullable) (transfer none): a `GdkDisplay`, or %NULL if
329 * there is no default display
330 */
331GdkDisplay *
332gdk_display_get_default (void)
333{
334 return gdk_display_manager_get_default_display (manager: gdk_display_manager_get ());
335}
336
337/**
338 * gdk_display_manager_set_default_display:
339 * @manager: a `GdkDisplayManager`
340 * @display: a `GdkDisplay`
341 *
342 * Sets @display as the default display.
343 */
344void
345gdk_display_manager_set_default_display (GdkDisplayManager *manager,
346 GdkDisplay *display)
347{
348 manager->default_display = display;
349
350 if (display)
351 GDK_DISPLAY_GET_CLASS (display)->make_default (display);
352
353 g_object_notify (G_OBJECT (manager), property_name: "default-display");
354}
355
356/**
357 * gdk_display_manager_list_displays:
358 * @manager: a `GdkDisplayManager`
359 *
360 * List all currently open displays.
361 *
362 * Returns: (transfer container) (element-type GdkDisplay): a newly
363 * allocated `GSList` of `GdkDisplay` objects
364 */
365GSList *
366gdk_display_manager_list_displays (GdkDisplayManager *manager)
367{
368 return g_slist_copy (list: manager->displays);
369}
370
371/**
372 * gdk_display_manager_open_display:
373 * @manager: a `GdkDisplayManager`
374 * @name: the name of the display to open
375 *
376 * Opens a display.
377 *
378 * Returns: (nullable) (transfer none): a `GdkDisplay`, or %NULL
379 * if the display could not be opened
380 */
381GdkDisplay *
382gdk_display_manager_open_display (GdkDisplayManager *manager,
383 const char *name)
384{
385 const char *backend_list;
386 GdkDisplay *display;
387 char **backends;
388 int i, j;
389 gboolean allow_any;
390
391 if (allowed_backends == NULL)
392 allowed_backends = "*";
393 allow_any = strstr (haystack: allowed_backends, needle: "*") != NULL;
394
395 backend_list = g_getenv (variable: "GDK_BACKEND");
396 if (backend_list == NULL)
397 backend_list = allowed_backends;
398 else if (g_strcmp0 (str1: backend_list, str2: "help") == 0)
399 {
400 fprintf (stderr, format: "Supported GDK backends:");
401 for (i = 0; gdk_backends[i].name != NULL; i++)
402 fprintf (stderr, format: " %s", gdk_backends[i].name);
403 fprintf (stderr, format: "\n");
404
405 backend_list = allowed_backends;
406 }
407 backends = g_strsplit (string: backend_list, delimiter: ",", max_tokens: 0);
408
409 display = NULL;
410
411 for (i = 0; display == NULL && backends[i] != NULL; i++)
412 {
413 const char *backend = backends[i];
414 gboolean any = g_str_equal (v1: backend, v2: "*");
415
416 if (!allow_any && !any && !strstr (haystack: allowed_backends, needle: backend))
417 continue;
418
419 for (j = 0; gdk_backends[j].name != NULL; j++)
420 {
421 if ((any && allow_any) ||
422 (any && strstr (haystack: allowed_backends, needle: gdk_backends[j].name)) ||
423 g_str_equal (v1: backend, v2: gdk_backends[j].name))
424 {
425 GDK_NOTE (MISC, g_message ("Trying %s backend", gdk_backends[j].name));
426 display = gdk_backends[j].open_display (name);
427 if (display)
428 break;
429 }
430 }
431 }
432
433 g_strfreev (str_array: backends);
434
435 return display;
436}
437
438void
439_gdk_display_manager_add_display (GdkDisplayManager *manager,
440 GdkDisplay *display)
441{
442 if (manager->displays == NULL)
443 gdk_display_manager_set_default_display (manager, display);
444
445 manager->displays = g_slist_prepend (list: manager->displays, data: display);
446
447 g_signal_emit (instance: manager, signal_id: signals[DISPLAY_OPENED], detail: 0, display);
448}
449
450/* NB: This function can be called multiple times per display. */
451void
452_gdk_display_manager_remove_display (GdkDisplayManager *manager,
453 GdkDisplay *display)
454{
455 manager->displays = g_slist_remove (list: manager->displays, data: display);
456
457 if (manager->default_display == display)
458 {
459 if (manager->displays)
460 gdk_display_manager_set_default_display (manager, display: manager->displays->data);
461 else
462 gdk_display_manager_set_default_display (manager, NULL);
463 }
464}
465

source code of gtk/gdk/gdkdisplaymanager.c