Learning_GTK4_tree/gdk/gdkdisplaymanager.c

476 lines
14 KiB
C

/* GDK - The GIMP Drawing Kit
* Copyright (C) 2000 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Modified by the GTK+ Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GTK+ Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GTK+ at ftp://ftp.gtk.org/pub/gtk/.
*/
#include "config.h"
#include "gdkconfig.h"
#include "gdkdisplaymanagerprivate.h"
#include "gdkdisplayprivate.h"
#include "gdkkeysprivate.h"
#include <glib/gi18n-lib.h>
#ifdef GDK_WINDOWING_X11
#include "x11/gdkx.h"
#include "x11/gdkprivate-x11.h"
#endif
#ifdef GDK_WINDOWING_BROADWAY
#include "broadway/gdkprivate-broadway.h"
#endif
#ifdef GDK_WINDOWING_MACOS
#include "macos/gdkmacosdisplay-private.h"
#endif
#ifdef GDK_WINDOWING_WIN32
#include "win32/gdkwin32.h"
#include "win32/gdkprivate-win32.h"
#endif
#ifdef GDK_WINDOWING_WAYLAND
#include "wayland/gdkprivate-wayland.h"
#endif
/**
* GdkDisplayManager:
*
* A singleton object that offers notification when displays appear or
* disappear.
*
* You can use [func@Gdk.DisplayManager.get] to obtain the `GdkDisplayManager`
* singleton, but that should be rarely necessary. Typically, initializing
* GTK opens a display that you can work with without ever accessing the
* `GdkDisplayManager`.
*
* The GDK library can be built with support for multiple backends.
* The `GdkDisplayManager` object determines which backend is used
* at runtime.
*
* In the rare case that you need to influence which of the backends
* is being used, you can use [func@Gdk.set_allowed_backends]. Note
* that you need to call this function before initializing GTK.
*
* ## Backend-specific code
*
* When writing backend-specific code that is supposed to work with
* multiple GDK backends, you have to consider both compile time and
* runtime. At compile time, use the `GDK_WINDOWING_X11`, `GDK_WINDOWING_WIN32`
* macros, etc. to find out which backends are present in the GDK library
* you are building your application against. At runtime, use type-check
* macros like GDK_IS_X11_DISPLAY() to find out which backend is in use:
*
* ```c
* #ifdef GDK_WINDOWING_X11
* if (GDK_IS_X11_DISPLAY (display))
* {
* // make X11-specific calls here
* }
* else
* #endif
* #ifdef GDK_WINDOWING_MACOS
* if (GDK_IS_MACOS_DISPLAY (display))
* {
* // make Quartz-specific calls here
* }
* else
* #endif
* g_error ("Unsupported GDK backend");
* ```
*/
enum {
PROP_0,
PROP_DEFAULT_DISPLAY
};
enum {
DISPLAY_OPENED,
LAST_SIGNAL
};
static void gdk_display_manager_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec);
static void gdk_display_manager_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec);
static guint signals[LAST_SIGNAL] = { 0 };
G_DEFINE_TYPE (GdkDisplayManager, gdk_display_manager, G_TYPE_OBJECT)
static void
gdk_display_manager_class_init (GdkDisplayManagerClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->set_property = gdk_display_manager_set_property;
object_class->get_property = gdk_display_manager_get_property;
/**
* GdkDisplayManager::display-opened:
* @manager: the object on which the signal is emitted
* @display: the opened display
*
* Emitted when a display is opened.
*/
signals[DISPLAY_OPENED] =
g_signal_new (g_intern_static_string ("display-opened"),
G_OBJECT_CLASS_TYPE (object_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GdkDisplayManagerClass, display_opened),
NULL, NULL,
NULL,
G_TYPE_NONE,
1,
GDK_TYPE_DISPLAY);
/**
* GdkDisplayManager:default-display: (attributes org.gtk.Property.get=gdk_display_manager_get_default_display)
*
* The default display.
*/
g_object_class_install_property (object_class,
PROP_DEFAULT_DISPLAY,
g_param_spec_object ("default-display", NULL, NULL,
GDK_TYPE_DISPLAY,
G_PARAM_READWRITE|G_PARAM_STATIC_STRINGS));
}
static void
gdk_display_manager_init (GdkDisplayManager *manager)
{
}
static void
gdk_display_manager_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
switch (prop_id)
{
case PROP_DEFAULT_DISPLAY:
gdk_display_manager_set_default_display (GDK_DISPLAY_MANAGER (object),
g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gdk_display_manager_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
switch (prop_id)
{
case PROP_DEFAULT_DISPLAY:
g_value_set_object (value,
gdk_display_manager_get_default_display (GDK_DISPLAY_MANAGER (object)));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static const char *allowed_backends;
/**
* gdk_set_allowed_backends:
* @backends: a comma-separated list of backends
*
* Sets a list of backends that GDK should try to use.
*
* This can be useful if your application does not
* work with certain GDK backends.
*
* By default, GDK tries all included backends.
*
* For example:
*
* ```c
* gdk_set_allowed_backends ("wayland,macos,*");
* ```
*
* instructs GDK to try the Wayland backend first, followed by the
* MacOs backend, and then all others.
*
* If the `GDK_BACKEND` environment variable is set, it determines
* what backends are tried in what order, while still respecting the
* set of allowed backends that are specified by this function.
*
* The possible backend names are:
*
* - `broadway`
* - `macos`
* - `wayland`.
* - `win32`
* - `x11`
*
* You can also include a `*` in the list to try all remaining backends.
*
* This call must happen prior to functions that open a display, such
* as [func@Gdk.Display.open], `gtk_init()`, or `gtk_init_check()`
* in order to take effect.
*/
void
gdk_set_allowed_backends (const char *backends)
{
allowed_backends = g_strdup (backends);
}
typedef struct _GdkBackend GdkBackend;
struct _GdkBackend {
const char *name;
GdkDisplay * (* open_display) (const char *name);
};
static GdkBackend gdk_backends[] = {
#ifdef GDK_WINDOWING_MACOS
{ "macos", _gdk_macos_display_open },
#endif
#ifdef GDK_WINDOWING_WIN32
{ "win32", _gdk_win32_display_open },
#endif
#ifdef GDK_WINDOWING_WAYLAND
{ "wayland", _gdk_wayland_display_open },
#endif
#ifdef GDK_WINDOWING_X11
{ "x11", gdk_x11_display_open },
#endif
#ifdef GDK_WINDOWING_BROADWAY
{ "broadway", _gdk_broadway_display_open },
#endif
/* NULL-terminating this array so we can use commas above */
{ NULL, NULL }
};
/**
* gdk_display_manager_get:
*
* Gets the singleton `GdkDisplayManager` object.
*
* When called for the first time, this function consults the
* `GDK_BACKEND` environment variable to find out which of the
* supported GDK backends to use (in case GDK has been compiled
* with multiple backends).
*
* Applications can use [func@set_allowed_backends] to limit what
* backends will be used.
*
* Returns: (transfer none): The global `GdkDisplayManager` singleton
*/
GdkDisplayManager*
gdk_display_manager_get (void)
{
static GdkDisplayManager *manager = NULL;
if (manager == NULL)
manager = g_object_new (GDK_TYPE_DISPLAY_MANAGER, NULL);
return manager;
}
/**
* gdk_display_manager_get_default_display: (attributes org.gtk.Method.get_property=default-display)
* @manager: a `GdkDisplayManager`
*
* Gets the default `GdkDisplay`.
*
* Returns: (nullable) (transfer none): a `GdkDisplay`
*/
GdkDisplay *
gdk_display_manager_get_default_display (GdkDisplayManager *manager)
{
return manager->default_display;
}
/**
* gdk_display_get_default:
*
* Gets the default `GdkDisplay`.
*
* This is a convenience function for:
*
* gdk_display_manager_get_default_display (gdk_display_manager_get ())
*
* Returns: (nullable) (transfer none): a `GdkDisplay`, or %NULL if
* there is no default display
*/
GdkDisplay *
gdk_display_get_default (void)
{
return gdk_display_manager_get_default_display (gdk_display_manager_get ());
}
/**
* gdk_display_manager_set_default_display:
* @manager: a `GdkDisplayManager`
* @display: a `GdkDisplay`
*
* Sets @display as the default display.
*/
void
gdk_display_manager_set_default_display (GdkDisplayManager *manager,
GdkDisplay *display)
{
manager->default_display = display;
if (display)
GDK_DISPLAY_GET_CLASS (display)->make_default (display);
g_object_notify (G_OBJECT (manager), "default-display");
}
/**
* gdk_display_manager_list_displays:
* @manager: a `GdkDisplayManager`
*
* List all currently open displays.
*
* Returns: (transfer container) (element-type GdkDisplay): a newly
* allocated `GSList` of `GdkDisplay` objects
*/
GSList *
gdk_display_manager_list_displays (GdkDisplayManager *manager)
{
return g_slist_copy (manager->displays);
}
/**
* gdk_display_manager_open_display:
* @manager: a `GdkDisplayManager`
* @name: (nullable): the name of the display to open
*
* Opens a display.
*
* Returns: (nullable) (transfer none): a `GdkDisplay`, or %NULL
* if the display could not be opened
*/
GdkDisplay *
gdk_display_manager_open_display (GdkDisplayManager *manager,
const char *name)
{
const char *backend_list;
GdkDisplay *display;
char **backends;
int i, j;
gboolean allow_any;
if (allowed_backends == NULL)
allowed_backends = "*";
allow_any = strstr (allowed_backends, "*") != NULL;
backend_list = g_getenv ("GDK_BACKEND");
if (backend_list == NULL)
backend_list = allowed_backends;
else if (g_strcmp0 (backend_list, "help") == 0)
{
fprintf (stderr, "Supported GDK backends:");
for (i = 0; gdk_backends[i].name != NULL; i++)
fprintf (stderr, " %s", gdk_backends[i].name);
fprintf (stderr, "\n");
backend_list = allowed_backends;
}
backends = g_strsplit (backend_list, ",", 0);
display = NULL;
for (i = 0; display == NULL && backends[i] != NULL; i++)
{
const char *backend = backends[i];
gboolean any = g_str_equal (backend, "*");
gboolean found = FALSE;
if (!allow_any && !any && !strstr (allowed_backends, backend))
{
GDK_DEBUG (MISC, "Skipping %s backend", backend);
continue;
}
for (j = 0; gdk_backends[j].name != NULL; j++)
{
if (g_str_equal (backend, gdk_backends[j].name))
found = TRUE;
if ((any && allow_any) ||
(any && strstr (allowed_backends, gdk_backends[j].name)) ||
g_str_equal (backend, gdk_backends[j].name))
{
GDK_DEBUG (MISC, "Trying %s backend", gdk_backends[j].name);
display = gdk_backends[j].open_display (name);
if (display)
{
GDK_DEBUG (MISC, "Using %s display %s", gdk_backends[j].name, gdk_display_get_name (display));
break;
}
}
}
if (!found && !any && !display)
g_warning ("No such backend: %s", backend);
}
g_strfreev (backends);
return display;
}
void
_gdk_display_manager_add_display (GdkDisplayManager *manager,
GdkDisplay *display)
{
if (manager->displays == NULL)
gdk_display_manager_set_default_display (manager, display);
manager->displays = g_slist_prepend (manager->displays, display);
g_signal_emit (manager, signals[DISPLAY_OPENED], 0, display);
}
/* NB: This function can be called multiple times per display. */
void
_gdk_display_manager_remove_display (GdkDisplayManager *manager,
GdkDisplay *display)
{
manager->displays = g_slist_remove (manager->displays, display);
if (manager->default_display == display)
{
if (manager->displays)
gdk_display_manager_set_default_display (manager, manager->displays->data);
else
gdk_display_manager_set_default_display (manager, NULL);
}
}