Creates a new #GApplication instance.
If non-%NULL, the application id must be valid. See g_application_id_is_valid().
If no application ID is given then some features of #GApplication (most notably application uniqueness) will be disabled.
the application id
the application flags
Whether the application is currently marked as busy through g_application_mark_busy() or g_application_bind_busy_property().
Emits the #GActionGroup::action-added signal on action_group.
This function should only be called by #GActionGroup implementations.
the name of an action in the group
Emits the #GActionGroup::action-enabled-changed signal on action_group.
This function should only be called by #GActionGroup implementations.
the name of an action in the group
whether or not the action is now enabled
Emits the #GActionGroup::action-removed signal on action_group.
This function should only be called by #GActionGroup implementations.
the name of an action in the group
Activates the application.
In essence, this results in the #GApplication::activate signal being emitted in the primary instance.
The application must be registered before calling this function.
Activate the named action within action_group.
If the action is expecting a parameter, then the correct type of
parameter must be given as parameter. If the action is expecting no
parameters then parameter must be %NULL. See
g_action_group_get_action_parameter_type().
If the #GActionGroup implementation supports asynchronous remote activation over D-Bus, this call may return before the relevant D-Bus traffic has been sent, or any replies have been received. In order to block on such asynchronous activation calls, g_dbus_connection_flush() should be called prior to the code, which depends on the result of the action activation. Without flushing the D-Bus connection, there is no guarantee that the action would have been activated.
The following code which runs in a remote app instance, shows an
example of a "quit" action being activated on the primary app
instance over D-Bus. Here g_dbus_connection_flush() is called
before exit(). Without g_dbus_connection_flush(), the "quit" action
may fail to be activated on the primary instance.
// call "quit" action on primary instance
g_action_group_activate_action (G_ACTION_GROUP (app), "quit", NULL);
// make sure the action is activated now
g_dbus_connection_flush (...);
g_debug ("application has been terminated. exiting.");
exit (0);
the name of the action to activate
parameters to the activation
A convenience function for creating multiple #GSimpleAction instances and adding them to a #GActionMap.
Each action is constructed as per one #GActionEntry.
static void
activate_quit (GSimpleAction *simple,
GVariant *parameter,
gpointer user_data)
{
exit (0);
}
static void
activate_print_string (GSimpleAction *simple,
GVariant *parameter,
gpointer user_data)
{
g_print ("%s\n", g_variant_get_string (parameter, NULL));
}
static GActionGroup *
create_action_group (void)
{
const GActionEntry entries[] = {
{ "quit", activate_quit },
{ "print-string", activate_print_string, "s" }
};
GSimpleActionGroup *group;
group = g_simple_action_group_new ();
g_action_map_add_action_entries (G_ACTION_MAP (group), entries, G_N_ELEMENTS (entries), NULL);
return G_ACTION_GROUP (group);
}
a pointer to the first item in an array of #GActionEntry structs
the user data for signal connections
Add an option to be handled by application.
Calling this function is the equivalent of calling g_application_add_main_option_entries() with a single #GOptionEntry that has its arg_data member set to %NULL.
The parsed arguments will be packed into a #GVariantDict which is passed to #GApplication::handle-local-options. If %G_APPLICATION_HANDLES_COMMAND_LINE is set, then it will also be sent to the primary instance. See g_application_add_main_option_entries() for more details.
See #GOptionEntry for more documentation of the arguments.
the long name of an option used to specify it in a commandline
the short name of an option
flags from #GOptionFlags
the type of the option, as a #GOptionArg
the description for the option in --help output
the placeholder to use for the extra argument parsed by the option in --help output
Adds main option entries to be handled by application.
This function is comparable to g_option_context_add_main_entries().
After the commandline arguments are parsed, the
#GApplication::handle-local-options signal will be emitted. At this
point, the application can inspect the values pointed to by arg_data
in the given #GOptionEntrys.
Unlike #GOptionContext, #GApplication supports giving a %NULL
arg_data for a non-callback #GOptionEntry. This results in the
argument in question being packed into a #GVariantDict which is also
passed to #GApplication::handle-local-options, where it can be
inspected and modified. If %G_APPLICATION_HANDLES_COMMAND_LINE is
set, then the resulting dictionary is sent to the primary instance,
where g_application_command_line_get_options_dict() will return it.
This "packing" is done according to the type of the argument --
booleans for normal flags, strings for strings, bytestrings for
filenames, etc. The packing only occurs if the flag is given (ie: we
do not pack a "false" #GVariant in the case that a flag is missing).
In general, it is recommended that all commandline arguments are
parsed locally. The options dictionary should then be used to
transmit the result of the parsing to the primary instance, where
g_variant_dict_lookup() can be used. For local options, it is
possible to either use arg_data in the usual way, or to consult (and
potentially remove) the option from the options dictionary.
This function is new in GLib 2.40. Before then, the only real choice was to send all of the commandline arguments (options and all) to the primary instance for handling. #GApplication ignored them completely on the local side. Calling this function "opts in" to the new behaviour, and in particular, means that unrecognised options will be treated as errors. Unrecognised options have never been ignored when %G_APPLICATION_HANDLES_COMMAND_LINE is unset.
If #GApplication::handle-local-options needs to see the list of
filenames, then the use of %G_OPTION_REMAINING is recommended. If
arg_data is %NULL then %G_OPTION_REMAINING can be used as a key into
the options dictionary. If you do use %G_OPTION_REMAINING then you
need to handle these arguments for yourself because once they are
consumed, they will no longer be visible to the default handling
(which treats them as filenames to be opened).
It is important to use the proper GVariant format when retrieving the options with g_variant_dict_lookup():
b&sixd^&ay^a&s^a&aya %NULL-terminated list of #GOptionEntrys
Adds a #GOptionGroup to the commandline handling of application.
This function is comparable to g_option_context_add_group().
Unlike g_application_add_main_option_entries(), this function does
not deal with %NULL arg_data and never transmits options to the
primary instance.
The reason for that is because, by the time the options arrive at the primary instance, it is typically too late to do anything with them. Taking the GTK option group as an example: GTK will already have been initialised by the time the #GApplication::command-line handler runs. In the case that this is not the first-running instance of the application, the existing instance may already have been running for a very long time.
This means that the options from #GOptionGroup are only really usable
in the case that the instance of the application being run is the
first instance. Passing options like --display= or --gdk-debug=
on future runs will have no effect on the existing primary instance.
Calling this function will cause the options in the supplied option group to be parsed, but it does not cause you to be "opted in" to the new functionality whereby unrecognised options are rejected even if %G_APPLICATION_HANDLES_COMMAND_LINE was given.
a #GOptionGroup
Marks application as busy (see g_application_mark_busy()) while
property on object is %TRUE.
The binding holds a reference to application while it is active, but
not to object. Instead, the binding is destroyed when object is
finalized.
Creates a binding between source_property on source and target_property
on target.
Whenever the source_property is changed the target_property is
updated using the same value. For instance:
g_object_bind_property (action, "active", widget, "sensitive", 0);
Will result in the "sensitive" property of the widget #GObject instance to be updated with the same value of the "active" property of the action #GObject instance.
If flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual:
if target_property on target changes then the source_property on source
will be updated as well.
The binding will automatically be removed when either the source or the
target instances are finalized. To remove the binding without affecting the
source and the target you can just call g_object_unref() on the returned
#GBinding instance.
Removing the binding by calling g_object_unref() on it must only be done if
the binding, source and target are only used from a single thread and it
is clear that both source and target outlive the binding. Especially it
is not safe to rely on this if the binding, source or target can be
finalized from different threads. Keep another reference to the binding and
use g_binding_unbind() instead to be on the safe side.
A #GObject can have multiple bindings.
the property on source to bind
the target #GObject
the property on target to bind
flags to pass to #GBinding
Creates a binding between source_property on source and target_property
on target, allowing you to set the transformation functions to be used by
the binding.
This function is the language bindings friendly version of g_object_bind_property_full(), using #GClosures instead of function pointers.
the property on source to bind
the target #GObject
the property on target to bind
flags to pass to #GBinding
a #GClosure wrapping the transformation function from the source to the target, or %NULL to use the default
a #GClosure wrapping the transformation function from the target to the source, or %NULL to use the default
Request for the state of the named action within action_group to be
changed to value.
The action must be stateful and value must be of the correct type.
See g_action_group_get_action_state_type().
This call merely requests a change. The action may refuse to change
its state or may change its state to something other than value.
See g_action_group_get_action_state_hint().
If the value GVariant is floating, it is consumed.
the name of the action to request the change on
the new state
This function is intended for #GObject implementations to re-enforce a [floating][floating-ref] object reference. Doing this is seldom required: all #GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().
Increases the freeze count on object. If the freeze count is
non-zero, the emission of "notify" signals on object is
stopped. The signals are queued until the freeze count is decreased
to zero. Duplicate notifications are squashed so that at most one
#GObject::notify signal is emitted for each property modified while the
object is frozen.
This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.
Checks if the named action within action_group is currently enabled.
An action must be enabled in order to be activated or in order to have its state changed from outside callers.
the name of the action to query
Queries the type of the parameter that must be given when activating
the named action within action_group.
When activating the action using g_action_group_activate_action(), the #GVariant given to that function must be of the type returned by this function.
In the case that this function returns %NULL, you must not give any #GVariant, but %NULL instead.
The parameter type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different parameter type.
the name of the action to query
Queries the current state of the named action within action_group.
If the action is not stateful then %NULL will be returned. If the action is stateful then the type of the return value is the type given by g_action_group_get_action_state_type().
The return value (if non-%NULL) should be freed with g_variant_unref() when it is no longer required.
the name of the action to query
Requests a hint about the valid range of values for the state of the
named action within action_group.
If %NULL is returned it either means that the action is not stateful or that there is no hint about the valid range of values for the state of the action.
If a #GVariant array is returned then each item in the array is a possible value for the state. If a #GVariant pair (ie: two-tuple) is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.
In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.
The return value (if non-%NULL) should be freed with g_variant_unref() when it is no longer required.
the name of the action to query
Queries the type of the state of the named action within
action_group.
If the action is stateful then this function returns the #GVariantType of the state. All calls to g_action_group_change_action_state() must give a #GVariant of this type and g_action_group_get_action_state() will return a #GVariant of the same type.
If the action is not stateful then this function will return %NULL. In that case, g_action_group_get_action_state() will return %NULL and you must not call g_action_group_change_action_state().
The state type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different state type.
the name of the action to query
Gets the unique identifier for application.
Gets a named field from the objects table of associations (see g_object_set_data()).
name of the key for that association
Gets the #GDBusConnection being used by the application, or %NULL.
If #GApplication is using its D-Bus backend then this function will return the #GDBusConnection being used for uniqueness and communication with the desktop environment and other instances of the application.
If #GApplication is not using D-Bus then this function will return %NULL. This includes the situation where the D-Bus backend would normally be in use but we were unable to connect to the bus.
This function must not be called before the application has been registered. See g_application_get_is_registered().
Gets the D-Bus object path being used by the application, or %NULL.
If #GApplication is using its D-Bus backend then this function will return the D-Bus object path that #GApplication is using. If the application is the primary instance then there is an object published at this path. If the application is not the primary instance then the result of this function is undefined.
If #GApplication is not using D-Bus then this function will return %NULL. This includes the situation where the D-Bus backend would normally be in use but we were unable to connect to the bus.
This function must not be called before the application has been registered. See g_application_get_is_registered().
Gets the flags for application.
See #GApplicationFlags.
Gets the current inactivity timeout for the application.
This is the amount of time (in milliseconds) after the last call to g_application_release() before the application stops running.
Gets the application's current busy state, as set through g_application_mark_busy() or g_application_bind_busy_property().
Checks if application is registered.
An application is registered if g_application_register() has been successfully called.
Checks if application is remote.
If application is remote then it means that another instance of
application already exists (the 'primary' instance). Calls to
perform actions on application will result in the actions being
performed by the primary instance.
The value of this property cannot be accessed before g_application_register() has been called. See g_application_get_is_registered().
Gets a property of an object.
The value can be:
In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling g_value_unset().
Note that g_object_get_property() is really intended for language bindings, g_object_get() is much more convenient for C programming.
the name of the property to get
return location for the property value
This function gets back user data pointers stored via g_object_set_qdata().
A #GQuark, naming the user data pointer
Gets the resource base path of application.
See g_application_set_resource_base_path() for more information.
Gets n_properties properties for an object.
Obtained properties will be set to values. All properties must be valid.
Warnings will be emitted and undefined behaviour may result if invalid
properties are passed in.
the names of each property to get
the values of each property to get
Checks if the named action exists within action_group.
the name of the action to check for
Increases the use count of application.
Use this function to indicate that the application has a reason to continue to run. For example, g_application_hold() is called by GTK+ when a toplevel window is on the screen.
To cancel the hold, call g_application_release().
Checks whether object has a [floating][floating-ref] reference.
Lists the actions contained within action_group.
The caller is responsible for freeing the list with g_strfreev() when it is no longer required.
Increases the busy count of application.
Use this function to indicate that the application is busy, for instance while a long running operation is pending.
The busy state will be exposed to other processes, so a session shell will use that information to indicate the state to the user (e.g. with a spinner).
To cancel the busy indication, use g_application_unmark_busy().
The application must be registered before calling this function.
Emits a "notify" signal for the property property_name on object.
When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.
Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.
the name of a property installed on the class of object.
Emits a "notify" signal for the property specified by pspec on object.
This function omits the property name lookup, hence it is faster than g_object_notify().
One way to avoid using g_object_notify() from within the class that registered the properties, and using g_object_notify_by_pspec() instead, is to store the GParamSpec used with g_object_class_install_property() inside a static array, e.g.:
enum
{
PROP_0,
PROP_FOO,
PROP_LAST
};
static GParamSpec *properties[PROP_LAST];
static void
my_object_class_init (MyObjectClass *klass)
{
properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
0, 100,
50,
G_PARAM_READWRITE);
g_object_class_install_property (gobject_class,
PROP_FOO,
properties[PROP_FOO]);
}
and then notify a change on the "foo" property with:
g_object_notify_by_pspec (self, properties[PROP_FOO]);
the #GParamSpec of a property installed on the class of object.
Opens the given files.
In essence, this results in the #GApplication::open signal being emitted in the primary instance.
n_files must be greater than zero.
hint is simply passed through to the ::open signal. It is
intended to be used by applications that have multiple modes for
opening files (eg: "view" vs "edit", etc). Unless you have a need
for this functionality, you should use "".
The application must be registered before calling this function and it must have the %G_APPLICATION_HANDLES_OPEN flag set.
Queries all aspects of the named action within an action_group.
This function acquires the information available from g_action_group_has_action(), g_action_group_get_action_enabled(), g_action_group_get_action_parameter_type(), g_action_group_get_action_state_type(), g_action_group_get_action_state_hint() and g_action_group_get_action_state() with a single function call.
This provides two main benefits.
The first is the improvement in efficiency that comes with not having to perform repeated lookups of the action in order to discover different things about it. The second is that implementing #GActionGroup can now be done by only overriding this one virtual function.
The interface provides a default implementation of this function that calls the individual functions, as required, to fetch the information. The interface also provides default implementations of those functions that call this function. All implementations, therefore, must override either this function or all of the others.
If the action exists, %TRUE is returned and any of the requested fields (as indicated by having a non-%NULL reference passed in) are filled. If the action doesn't exist, %FALSE is returned and the fields may or may not have been modified.
the name of an action in the group
Immediately quits the application.
Upon return to the mainloop, g_application_run() will return, calling only the 'shutdown' function before doing so.
The hold count is ignored. Take care if your code has called g_application_hold() on the application and is therefore still expecting it to exist. (Note that you may have called g_application_hold() indirectly, for example through gtk_application_add_window().)
The result of calling g_application_run() again after it returns is unspecified.
Increase the reference count of object, and possibly remove the
[floating][floating-ref] reference, if object has a floating reference.
In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.
Since GLib 2.56, the type of object will be propagated to the return type
under the same conditions as for g_object_ref().
Attempts registration of the application.
This is the point at which the application discovers if it is the primary instance or merely acting as a remote for an already-existing primary instance. This is implemented by attempting to acquire the application identifier as a unique bus name on the session bus using GDBus.
If there is no application ID or if %G_APPLICATION_NON_UNIQUE was given, then this process will always become the primary instance.
Due to the internal architecture of GDBus, method calls can be dispatched at any time (even if a main loop is not running). For this reason, you must ensure that any object paths that you wish to register are registered before calling this function.
If the application has already been registered then %TRUE is returned with no work performed.
The #GApplication::startup signal is emitted if registration succeeds
and application is the primary instance (including the non-unique
case).
In the event of an error (such as cancellable being cancelled, or a
failure to connect to the session bus), %FALSE is returned and error
is set appropriately.
Note: the return value of this function is not an indicator that this instance is or is not the primary instance of the application. See g_application_get_is_remote() for that.
a #GCancellable, or %NULL
Decrease the use count of application.
When the use count reaches zero, the application will stop running.
Never call this function except to cancel the effect of a previous call to g_application_hold().
Removes the named action from the action map.
If no action of this name is in the map then nothing happens.
the name of the action
Runs the application.
This function is intended to be run from main() and its return value
is intended to be returned by main(). Although you are expected to pass
the argc, argv parameters from main() to this function, it is possible
to pass %NULL if argv is not available or commandline handling is not
required. Note that on Windows, argc and argv are ignored, and
g_win32_get_command_line() is called internally (for proper support
of Unicode commandline arguments).
#GApplication will attempt to parse the commandline arguments. You can add commandline flags to the list of recognised options by way of g_application_add_main_option_entries(). After this, the #GApplication::handle-local-options signal is emitted, from which the application can inspect the values of its #GOptionEntrys.
#GApplication::handle-local-options is a good place to handle options
such as --version, where an immediate reply from the local process is
desired (instead of communicating with an already-running instance).
A #GApplication::handle-local-options handler can stop further processing
by returning a non-negative value, which then becomes the exit status of
the process.
What happens next depends on the flags: if %G_APPLICATION_HANDLES_COMMAND_LINE was specified then the remaining commandline arguments are sent to the primary instance, where a #GApplication::command-line signal is emitted. Otherwise, the remaining commandline arguments are assumed to be a list of files. If there are no files listed, the application is activated via the #GApplication::activate signal. If there are one or more files, and %G_APPLICATION_HANDLES_OPEN was specified then the files are opened via the #GApplication::open signal.
If you are interested in doing more complicated local handling of the commandline then you should implement your own #GApplication subclass and override local_command_line(). In this case, you most likely want to return %TRUE from your local_command_line() implementation to suppress the default handling. See [gapplication-example-cmdline2.c][https://gitlab.gnome.org/GNOME/glib/-/blob/HEAD/gio/tests/gapplication-example-cmdline2.c] for an example.
If, after the above is done, the use count of the application is zero then the exit status is returned immediately. If the use count is non-zero then the default main context is iterated until the use count falls to zero, at which point 0 is returned.
If the %G_APPLICATION_IS_SERVICE flag is set, then the service will run for as much as 10 seconds with a use count of zero while waiting for the message that caused the activation to arrive. After that, if the use count falls to zero the application will exit immediately, except in the case that g_application_set_inactivity_timeout() is in use.
This function sets the prgname (g_set_prgname()), if not already set, to the basename of argv[0].
Much like g_main_loop_run(), this function will acquire the main context for the duration that the application is running.
Since 2.40, applications that are not explicitly flagged as services or launchers (ie: neither %G_APPLICATION_IS_SERVICE or %G_APPLICATION_IS_LAUNCHER are given as flags) will check (from the default handler for local_command_line) if "--gapplication-service" was given in the command line. If this flag is present then normal commandline processing is interrupted and the %G_APPLICATION_IS_SERVICE flag is set. This provides a "compromise" solution whereby running an application directly from the commandline will invoke it in the normal way (which can be useful for debugging) while still allowing applications to be D-Bus activated in service mode. The D-Bus service file should invoke the executable with "--gapplication-service" as the sole commandline argument. This approach is suitable for use by most graphical applications but should not be used from applications like editors that need precise control over when processes invoked via the commandline will exit and what their exit status will be.
the argv from main(), or %NULL
Releases all references to other objects. This can be used to break reference cycles.
This function should only be called from object system implementations.
Sends a notification on behalf of application to the desktop shell.
There is no guarantee that the notification is displayed immediately,
or even at all.
Notifications may persist after the application exits. It will be D-Bus-activated when the notification or one of its actions is activated.
Modifying notification after this call has no effect. However, the
object can be reused for a later call to this function.
id may be any string that uniquely identifies the event for the
application. It does not need to be in any special format. For
example, "new-message" might be appropriate for a notification about
new messages.
If a previous notification was sent with the same id, it will be
replaced with notification and shown again as if it was a new
notification. This works even for notifications sent from a previous
execution of the application, as long as id is the same string.
id may be %NULL, but it is impossible to replace or withdraw
notifications without an id.
If notification is no longer relevant, it can be withdrawn with
g_application_withdraw_notification().
id of the notification, or %NULL
the #GNotification to send
This used to be how actions were associated with a #GApplication. Now there is #GActionMap for that.
a #GActionGroup, or %NULL
Sets the unique identifier for application.
The application id can only be modified if application has not yet
been registered.
If non-%NULL, the application id must be valid. See g_application_id_is_valid().
the identifier for application
Each object carries around a table of associations from strings to pointers. This function lets you set an association.
If the object already had an association with that name, the old association will be destroyed.
Internally, the key is converted to a #GQuark using g_quark_from_string().
This means a copy of key is kept permanently (even after object has been
finalized) — so it is recommended to only use a small, bounded set of values
for key in your program, to avoid the #GQuark storage growing unbounded.
name of the key
data to associate with that key
Sets or unsets the default application for the process, as returned by g_application_get_default().
This function does not take its own reference on application. If
application is destroyed then the default application will revert
back to %NULL.
Sets the flags for application.
The flags can only be modified if application has not yet been
registered.
See #GApplicationFlags.
the flags for application
Sets the current inactivity timeout for the application.
This is the amount of time (in milliseconds) after the last call to g_application_release() before the application stops running.
This call has no side effects of its own. The value set here is only used for next time g_application_release() drops the use count to zero. Any timeouts currently in progress are not impacted.
the timeout, in milliseconds
Adds a description to the application option context.
See g_option_context_set_description() for more information.
a string to be shown in --help output after the list of options, or %NULL
Sets the parameter string to be used by the commandline handling of application.
This function registers the argument to be passed to g_option_context_new()
when the internal #GOptionContext of application is created.
See g_option_context_new() for more information about parameter_string.
a string which is displayed in the first line of --help output, after the usage summary programname [OPTION...].
Adds a summary to the application option context.
See g_option_context_set_summary() for more information.
a string to be shown in --help output before the list of options, or %NULL
Sets a property on an object.
the name of the property to set
the value
Sets (or unsets) the base resource path of application.
The path is used to automatically load various [application resources][gresource] such as menu layouts and action descriptions. The various types of resources will be found at fixed names relative to the given base path.
By default, the resource base path is determined from the application ID by prefixing '/' and replacing each '.' with '/'. This is done at the time that the #GApplication object is constructed. Changes to the application ID after that point will not have an impact on the resource base path.
As an example, if the application has an ID of "org.example.app" then the default resource base path will be "/org/example/app". If this is a #GtkApplication (and you have not manually changed the path) then Gtk will then search for the menus of the application at "/org/example/app/gtk/menus.ui".
See #GResource for more information about adding resources to your application.
You can disable automatic resource loading functionality by setting the path to %NULL.
Changing the resource base path once the application is running is not recommended. The point at which the resource path is consulted for forming paths for various purposes is unspecified. When writing a sub-class of #GApplication you should either set the #GApplication:resource-base-path property at construction time, or call this function during the instance initialization. Alternatively, you can call this function in the #GApplicationClass.startup virtual function, before chaining up to the parent implementation.
the resource path to use
Remove a specified datum from the object's data associations, without invoking the association's destroy handler.
name of the key
This function gets back user data pointers stored via
g_object_set_qdata() and removes the data from object
without invoking its destroy() function (if any was
set).
Usually, calling this function is only required to update
user data pointers with a destroy notifier, for example:
void
object_add_to_user_list (GObject *object,
const gchar *new_string)
{
// the quark, naming the object data
GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
// retrieve the old string list
GList *list = g_object_steal_qdata (object, quark_string_list);
// prepend new string
list = g_list_prepend (list, g_strdup (new_string));
// this changed 'list', so we need to set it again
g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
GList *node, *list = data;
for (node = list; node; node = node->next)
g_free (node->data);
g_list_free (list);
}
Using g_object_get_qdata() in the above example, instead of g_object_steal_qdata() would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().
A #GQuark, naming the user data pointer
Reverts the effect of a previous call to
g_object_freeze_notify(). The freeze count is decreased on object
and when it reaches zero, queued "notify" signals are emitted.
Duplicate notifications for each property are squashed so that at most one #GObject::notify signal is emitted for each property, in the reverse order in which they have been queued.
It is an error to call this function when the freeze count is zero.
Decreases the busy count of application.
When the busy count reaches zero, the new state will be propagated to other processes.
This function must only be called to cancel the effect of a previous call to g_application_mark_busy().
Decreases the reference count of object. When its reference count
drops to 0, the object is finalized (i.e. its memory is freed).
If the pointer to the #GObject may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to %NULL rather than retain a dangling pointer to a potentially invalid #GObject instance. Use g_clear_object() for this.
Emits the #GActionGroup::action-added signal on action_group.
This function should only be called by #GActionGroup implementations.
the name of an action in the group
Emits the #GActionGroup::action-enabled-changed signal on action_group.
This function should only be called by #GActionGroup implementations.
the name of an action in the group
whether or not the action is now enabled
Emits the #GActionGroup::action-removed signal on action_group.
This function should only be called by #GActionGroup implementations.
the name of an action in the group
Activates the application.
In essence, this results in the #GApplication::activate signal being emitted in the primary instance.
The application must be registered before calling this function.
Activate the named action within action_group.
If the action is expecting a parameter, then the correct type of
parameter must be given as parameter. If the action is expecting no
parameters then parameter must be %NULL. See
g_action_group_get_action_parameter_type().
If the #GActionGroup implementation supports asynchronous remote activation over D-Bus, this call may return before the relevant D-Bus traffic has been sent, or any replies have been received. In order to block on such asynchronous activation calls, g_dbus_connection_flush() should be called prior to the code, which depends on the result of the action activation. Without flushing the D-Bus connection, there is no guarantee that the action would have been activated.
The following code which runs in a remote app instance, shows an
example of a "quit" action being activated on the primary app
instance over D-Bus. Here g_dbus_connection_flush() is called
before exit(). Without g_dbus_connection_flush(), the "quit" action
may fail to be activated on the primary instance.
// call "quit" action on primary instance
g_action_group_activate_action (G_ACTION_GROUP (app), "quit", NULL);
// make sure the action is activated now
g_dbus_connection_flush (...);
g_debug ("application has been terminated. exiting.");
exit (0);
the name of the action to activate
parameters to the activation
Request for the state of the named action within action_group to be
changed to value.
The action must be stateful and value must be of the correct type.
See g_action_group_get_action_state_type().
This call merely requests a change. The action may refuse to change
its state or may change its state to something other than value.
See g_action_group_get_action_state_hint().
If the value GVariant is floating, it is consumed.
the name of the action to request the change on
the new state
Checks if the named action within action_group is currently enabled.
An action must be enabled in order to be activated or in order to have its state changed from outside callers.
the name of the action to query
Queries the type of the parameter that must be given when activating
the named action within action_group.
When activating the action using g_action_group_activate_action(), the #GVariant given to that function must be of the type returned by this function.
In the case that this function returns %NULL, you must not give any #GVariant, but %NULL instead.
The parameter type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different parameter type.
the name of the action to query
Queries the current state of the named action within action_group.
If the action is not stateful then %NULL will be returned. If the action is stateful then the type of the return value is the type given by g_action_group_get_action_state_type().
The return value (if non-%NULL) should be freed with g_variant_unref() when it is no longer required.
the name of the action to query
Requests a hint about the valid range of values for the state of the
named action within action_group.
If %NULL is returned it either means that the action is not stateful or that there is no hint about the valid range of values for the state of the action.
If a #GVariant array is returned then each item in the array is a possible value for the state. If a #GVariant pair (ie: two-tuple) is returned then the tuple specifies the inclusive lower and upper bound of valid values for the state.
In any case, the information is merely a hint. It may be possible to have a state value outside of the hinted range and setting a value within the range may fail.
The return value (if non-%NULL) should be freed with g_variant_unref() when it is no longer required.
the name of the action to query
Queries the type of the state of the named action within
action_group.
If the action is stateful then this function returns the #GVariantType of the state. All calls to g_action_group_change_action_state() must give a #GVariant of this type and g_action_group_get_action_state() will return a #GVariant of the same type.
If the action is not stateful then this function will return %NULL. In that case, g_action_group_get_action_state() will return %NULL and you must not call g_action_group_change_action_state().
The state type of a particular action will never change but it is possible for an action to be removed and for a new action to be added with the same name but a different state type.
the name of the action to query
Checks if the named action exists within action_group.
the name of the action to check for
Lists the actions contained within action_group.
The caller is responsible for freeing the list with g_strfreev() when it is no longer required.
This virtual function is always invoked in the local instance. It
gets passed a pointer to a %NULL-terminated copy of argv and is
expected to remove arguments that it handled (shifting up remaining
arguments).
The last argument to local_command_line() is a pointer to the status
variable which can used to set the exit status that is returned from
g_application_run().
See g_application_run() for more details on #GApplication startup.
array of command line arguments
Emits a "notify" signal for the property property_name on object.
When possible, eg. when signaling a property change from within the class that registered the property, you should use g_object_notify_by_pspec() instead.
Note that emission of the notify signal may be blocked with g_object_freeze_notify(). In this case, the signal emissions are queued and will be emitted (in reverse order) when g_object_thaw_notify() is called.
Opens the given files.
In essence, this results in the #GApplication::open signal being emitted in the primary instance.
n_files must be greater than zero.
hint is simply passed through to the ::open signal. It is
intended to be used by applications that have multiple modes for
opening files (eg: "view" vs "edit", etc). Unless you have a need
for this functionality, you should use "".
The application must be registered before calling this function and it must have the %G_APPLICATION_HANDLES_OPEN flag set.
Queries all aspects of the named action within an action_group.
This function acquires the information available from g_action_group_has_action(), g_action_group_get_action_enabled(), g_action_group_get_action_parameter_type(), g_action_group_get_action_state_type(), g_action_group_get_action_state_hint() and g_action_group_get_action_state() with a single function call.
This provides two main benefits.
The first is the improvement in efficiency that comes with not having to perform repeated lookups of the action in order to discover different things about it. The second is that implementing #GActionGroup can now be done by only overriding this one virtual function.
The interface provides a default implementation of this function that calls the individual functions, as required, to fetch the information. The interface also provides default implementations of those functions that call this function. All implementations, therefore, must override either this function or all of the others.
If the action exists, %TRUE is returned and any of the requested fields (as indicated by having a non-%NULL reference passed in) are filled. If the action doesn't exist, %FALSE is returned and the fields may or may not have been modified.
the name of an action in the group
Removes the named action from the action map.
If no action of this name is in the map then nothing happens.
the name of the action
This function essentially limits the life time of the closure to
the life time of the object. That is, when the object is finalized,
the closure is invalidated by calling g_closure_invalidate() on
it, in order to prevent invocations of the closure with a finalized
(nonexisting) object. Also, g_object_ref() and g_object_unref() are
added as marshal guards to the closure, to ensure that an extra
reference count is held on object during invocation of the
closure. Usually, this function will be called on closures that
use this object as closure data.
#GClosure to watch
Withdraws a notification that was sent with g_application_send_notification().
This call does nothing if a notification with id doesn't exist or
the notification was never sent.
This function works even for notifications sent in previous
executions of this application, as long id is the same as it was for
the sent notification.
Note that notifications are dismissed when the user clicks on one of the buttons in a notification or triggers its default action, so there is no need to explicitly withdraw the notification in that case.
id of a previously sent notification
Returns the default #GApplication instance for this process.
Normally there is only one #GApplication per process and it becomes the default when it is created. You can exercise more control over this by using g_application_set_default().
If there is no default application then %NULL is returned.
Checks if application_id is a valid application identifier.
A valid ID is required for calls to g_application_new() and g_application_set_application_id().
Application identifiers follow the same format as D-Bus well-known bus names. For convenience, the restrictions on application identifiers are reproduced here:
Application identifiers are composed of 1 or more elements separated by a
period (.) character. All elements must contain at least one character.
Each element must only contain the ASCII characters [A-Z][a-z][0-9]_-,
with - discouraged in new application identifiers. Each element must not
begin with a digit.
Application identifiers must contain at least one . (period) character
(and thus at least two elements).
Application identifiers must not begin with a . (period) character.
Application identifiers must not exceed 255 characters.
Note that the hyphen (-) character is allowed in application identifiers,
but is problematic or not allowed in various specifications and APIs that
refer to D-Bus, such as
Flatpak application IDs,
the
DBusActivatable interface in the Desktop Entry Specification,
and the convention that an application's "main" interface and object path
resemble its application identifier and bus name. To avoid situations that
require special-case handling, it is recommended that new application
identifiers consistently replace hyphens with underscores.
Like D-Bus interface names, application identifiers should start with the reversed DNS domain name of the author of the interface (in lower-case), and it is conventional for the rest of the application identifier to consist of words run together, with initial capital letters.
As with D-Bus interface names, if the author's DNS domain name contains
hyphen/minus characters they should be replaced by underscores, and if it
contains leading digits they should be escaped by prepending an underscore.
For example, if the owner of 7-zip.org used an application identifier for an
archiving application, it might be named org._7_zip.Archiver.
a potential application identifier
Find the #GParamSpec with the given name for an
interface. Generally, the interface vtable passed in as g_iface
will be the default vtable from g_type_default_interface_ref(), or,
if you know the interface has already been loaded,
g_type_default_interface_peek().
any interface vtable for the interface, or the default vtable for the interface
name of a property to look up.
Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created #GParamSpec, but normally g_object_class_override_property() will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.
This function is meant to be called from the interface's default
vtable initialization function (the class_init member of
#GTypeInfo.) It must not be called after after class_init has
been called for any object types implementing this interface.
If pspec is a floating reference, it will be consumed.
any interface vtable for the interface, or the default vtable for the interface.
the #GParamSpec for the new property
Lists the properties of an interface.Generally, the interface
vtable passed in as g_iface will be the default vtable from
g_type_default_interface_ref(), or, if you know the interface has
already been loaded, g_type_default_interface_peek().
any interface vtable for the interface, or the default vtable for the interface
Creates a new #GApplication instance.
If non-%NULL, the application id must be valid. See g_application_id_is_valid().
If no application ID is given then some features of #GApplication (most notably application uniqueness) will be disabled.
the application id
the application flags
Creates a new instance of a #GObject subtype and sets its properties.
Construction parameters (see %G_PARAM_CONSTRUCT, %G_PARAM_CONSTRUCT_ONLY) which are not explicitly specified are set to their default values.
the type id of the #GObject subtype to instantiate
an array of #GParameter
A #GApplication is the foundation of an application. It wraps some low-level platform-specific services and is intended to act as the foundation for higher-level application classes such as #GtkApplication or #MxApplication. In general, you should not use this class outside of a higher level framework.
GApplication provides convenient life cycle management by maintaining a "use count" for the primary application instance. The use count can be changed using g_application_hold() and g_application_release(). If it drops to zero, the application exits. Higher-level classes such as #GtkApplication employ the use count to ensure that the application stays alive as long as it has any opened windows.
Another feature that GApplication (optionally) provides is process uniqueness. Applications can make use of this functionality by providing a unique application ID. If given, only one application with this ID can be running at a time per session. The session concept is platform-dependent, but corresponds roughly to a graphical desktop login. When your application is launched again, its arguments are passed through platform communication to the already running program. The already running instance of the program is called the "primary instance"; for non-unique applications this is always the current instance. On Linux, the D-Bus session bus is used for communication.
The use of #GApplication differs from some other commonly-used uniqueness libraries (such as libunique) in important ways. The application is not expected to manually register itself and check if it is the primary instance. Instead, the main() function of a #GApplication should do very little more than instantiating the application instance, possibly connecting signal handlers, then calling g_application_run(). All checks for uniqueness are done internally. If the application is the primary instance then the startup signal is emitted and the mainloop runs. If the application is not the primary instance then a signal is sent to the primary instance and g_application_run() promptly returns. See the code examples below.
If used, the expected form of an application identifier is the same as that of of a D-Bus well-known bus name. Examples include:
com.example.MyApp,org.example.internal_apps.Calculator,org._7_zip.Archiver. For details on valid application identifiers, see g_application_id_is_valid().On Linux, the application identifier is claimed as a well-known bus name on the user's session bus. This means that the uniqueness of your application is scoped to the current session. It also means that your application may provide additional services (through registration of other object paths) at that bus name. The registration of these object paths should be done with the shared GDBus session bus. Note that due to the internal architecture of GDBus, method calls can be dispatched at any time (even if a main loop is not running). For this reason, you must ensure that any object paths that you wish to register are registered before #GApplication attempts to acquire the bus name of your application (which happens in g_application_register()). Unfortunately, this means that you cannot use g_application_get_is_remote() to decide if you want to register object paths.
GApplication also implements the #GActionGroup and #GActionMap interfaces and lets you easily export actions by adding them with g_action_map_add_action(). When invoking an action by calling g_action_group_activate_action() on the application, it is always invoked in the primary instance. The actions are also exported on the session bus, and GIO provides the #GDBusActionGroup wrapper to conveniently access them remotely. GIO provides a #GDBusMenuModel wrapper for remote access to exported #GMenuModels.
There is a number of different entry points into a GApplication:
via 'Activate' (i.e. just starting the application)
via 'Open' (i.e. opening some files)
by handling a command-line
via activating an action
The #GApplication::startup signal lets you handle the application initialization for all of these in a single place.
Regardless of which of these entry points is used to start the application, GApplication passes some ‘platform data’ from the launching instance to the primary instance, in the form of a #GVariant dictionary mapping strings to variants. To use platform data, override the
before_emitorafter_emitvirtual functions in your #GApplication subclass. When dealing with #GApplicationCommandLine objects, the platform data is directly available via g_application_command_line_get_cwd(), g_application_command_line_get_environ() and g_application_command_line_get_platform_data().As the name indicates, the platform data may vary depending on the operating system, but it always includes the current directory (key "cwd"), and optionally the environment (ie the set of environment variables and their values) of the calling process (key "environ"). The environment is only added to the platform data if the %G_APPLICATION_SEND_ENVIRONMENT flag is set. #GApplication subclasses can add their own platform data by overriding the
add_platform_datavirtual function. For instance, #GtkApplication adds startup notification data in this way.To parse commandline arguments you may handle the #GApplication::command-line signal or override the local_command_line() vfunc, to parse them in either the primary instance or the local instance, respectively.
For an example of opening files with a GApplication, see gapplication-example-open.c.
For an example of using actions with GApplication, see gapplication-example-actions.c.
For an example of using extra D-Bus hooks with GApplication, see gapplication-example-dbushooks.c.