Class

GioApplication

Description [src]

class Gio.Application : GObject.Object {
  /* No available fields */
}

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_emit or after_emit virtual 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_data virtual 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.

Available since:2.28

Hierarchy

hierarchy this GApplication implements_0 GActionGroup this--implements_0 implements_1 GActionMap this--implements_1 ancestor_0 GObject ancestor_0--this

Ancestors

Constructors

g_application_new

Creates a new GApplication instance.

Functions

g_application_get_default

Returns the default GApplication instance for this process.

Available since: 2.32

g_application_id_is_valid

Checks if application_id is a valid application identifier.

Instance methods

g_application_activate

Activates the application.

Available since: 2.28

g_application_add_main_option

Add an option to be handled by application.

Available since: 2.42

g_application_add_main_option_entries

Adds main option entries to be handled by application.

Available since: 2.40

g_application_add_option_group

Adds a GOptionGroup to the commandline handling of application.

Available since: 2.40

g_application_bind_busy_property

Marks application as busy (see g_application_mark_busy()) while property on object is TRUE.

Available since: 2.44

g_application_get_application_id

Gets the unique identifier for application.

Available since: 2.28

g_application_get_dbus_connection

Gets the GDBusConnection being used by the application, or NULL.

Available since: 2.34

g_application_get_dbus_object_path

Gets the D-Bus object path being used by the application, or NULL.

Available since: 2.34

g_application_get_flags

Gets the flags for application.

Available since: 2.28

g_application_get_inactivity_timeout

Gets the current inactivity timeout for the application.

Available since: 2.28

g_application_get_is_busy

Gets the application’s current busy state, as set through g_application_mark_busy() or g_application_bind_busy_property().

Available since: 2.44

g_application_get_is_registered

Checks if application is registered.

Available since: 2.28

g_application_get_is_remote

Checks if application is remote.

Available since: 2.28

g_application_get_resource_base_path

Gets the resource base path of application.

Available since: 2.42

g_application_hold

Increases the use count of application.

g_application_mark_busy

Increases the busy count of application.

Available since: 2.38

g_application_open

Opens the given files.

Available since: 2.28

g_application_quit

Immediately quits the application.

Available since: 2.32

g_application_register

Attempts registration of the application.

Available since: 2.28

g_application_release

Decrease the use count of application.

g_application_run

Runs the application.

Available since: 2.28

g_application_send_notification

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.

Available since: 2.40

g_application_set_action_group

This used to be how actions were associated with a GApplication. Now there is GActionMap for that.

Available since: 2.28

Deprecated since: 2.32

g_application_set_application_id

Sets the unique identifier for application.

Available since: 2.28

g_application_set_default

Sets or unsets the default application for the process, as returned by g_application_get_default().

Available since: 2.32

g_application_set_flags

Sets the flags for application.

Available since: 2.28

g_application_set_inactivity_timeout

Sets the current inactivity timeout for the application.

Available since: 2.28

g_application_set_option_context_description

Adds a description to the application option context.

Available since: 2.56

g_application_set_option_context_parameter_string

Sets the parameter string to be used by the commandline handling of application.

Available since: 2.56

g_application_set_option_context_summary

Adds a summary to the application option context.

Available since: 2.56

g_application_set_resource_base_path

Sets (or unsets) the base resource path of application.

Available since: 2.42

g_application_unbind_busy_property

Destroys a binding between property and the busy state of application that was previously created with g_application_bind_busy_property().

Available since: 2.44

g_application_unmark_busy

Decreases the busy count of application.

Available since: 2.38

g_application_withdraw_notification

Withdraws a notification that was sent with g_application_send_notification().

Available since: 2.40

Methods inherited from GObject (43)
Methods inherited from GActionGroup (14)
g_action_group_action_added

Emits the GActionGroup::action-added signal on action_group.

Available since: 2.28

g_action_group_action_enabled_changed

Emits the GActionGroup::action-enabled-changed signal on action_group.

Available since: 2.28

g_action_group_action_removed

Emits the GActionGroup::action-removed signal on action_group.

Available since: 2.28

g_action_group_action_state_changed

Emits the GActionGroup::action-state-changed signal on action_group.

Available since: 2.28

g_action_group_activate_action

Activate the named action within action_group.

Available since: 2.28

g_action_group_change_action_state

Request for the state of the named action within action_group to be changed to value.

Available since: 2.28

g_action_group_get_action_enabled

Checks if the named action within action_group is currently enabled.

Available since: 2.28

g_action_group_get_action_parameter_type

Queries the type of the parameter that must be given when activating the named action within action_group.

Available since: 2.28

g_action_group_get_action_state

Queries the current state of the named action within action_group.

Available since: 2.28

g_action_group_get_action_state_hint

Requests a hint about the valid range of values for the state of the named action within action_group.

Available since: 2.28

g_action_group_get_action_state_type

Queries the type of the state of the named action within action_group.

Available since: 2.28

g_action_group_has_action

Checks if the named action exists within action_group.

Available since: 2.28

g_action_group_list_actions

Lists the actions contained within action_group.

Available since: 2.28

g_action_group_query_action

Queries all aspects of the named action within an action_group.

Available since: 2.32

Methods inherited from GActionMap (4)
g_action_map_add_action

Adds an action to the action_map.

Available since: 2.32

g_action_map_add_action_entries

A convenience function for creating multiple GSimpleAction instances and adding them to a GActionMap.

Available since: 2.32

g_action_map_lookup_action

Looks up the action with the name action_name in action_map.

Available since: 2.32

g_action_map_remove_action

Removes the named action from the action map.

Available since: 2.32

Properties

Gio.Application:action-group
No description available.
Gio.Application:application-id
No description available.
Gio.Application:flags
No description available.
Gio.Application:inactivity-timeout
No description available.
Gio.Application:is-busy

Whether the application is currently marked as busy through g_application_mark_busy() or g_application_bind_busy_property().

Available since: 2.44

Gio.Application:is-registered
No description available.
Gio.Application:is-remote
No description available.
Gio.Application:resource-base-path
No description available.

Signals

Gio.Application::activate

The ::activate signal is emitted on the primary instance when an activation occurs. See g_application_activate().

Gio.Application::command-line

The ::command-line signal is emitted on the primary instance when a commandline is not handled locally. See g_application_run() and the GApplicationCommandLine documentation for more information.

Gio.Application::handle-local-options

The ::handle-local-options signal is emitted on the local instance after the parsing of the commandline options has occurred.

Available since: 2.40

Gio.Application::name-lost

The ::name-lost signal is emitted only on the registered primary instance when a new instance has taken over. This can only happen if the application is using the G_APPLICATION_ALLOW_REPLACEMENT flag.

Available since: 2.60

Gio.Application::open

The ::open signal is emitted on the primary instance when there are files to open. See g_application_open() for more information.

Gio.Application::shutdown

The ::shutdown signal is emitted only on the registered primary instance immediately after the main loop terminates.

Gio.Application::startup

The ::startup signal is emitted on the primary instance immediately after registration. See g_application_register().

Signals inherited from GObject (1)
Signals inherited from GActionGroup (4)
Gio.ActionGroup::action-added

Signals that a new action was just added to the group. This signal is emitted after the action has been added and is now visible.

Available since: 2.28

Gio.ActionGroup::action-enabled-changed

Signals that the enabled status of the named action has changed.

Available since: 2.28

Gio.ActionGroup::action-removed

Signals that an action is just about to be removed from the group. This signal is emitted before the action is removed, so the action is still visible and can be queried from the signal handler.

Available since: 2.28

Gio.ActionGroup::action-state-changed

Signals that the state of the named action has changed.

Available since: 2.28

Class structure

struct GioApplicationClass {
  void (* startup) (
    GApplication* application
  );
  void (* activate) (
    GApplication* application
  );
  void (* open) (
    GApplication* application,
    GFile** files,
    gint n_files,
    const gchar* hint
  );
  int (* command_line) (
    GApplication* application,
    GApplicationCommandLine* command_line
  );
  gboolean (* local_command_line) (
    GApplication* application,
    gchar*** arguments,
    int* exit_status
  );
  void (* before_emit) (
    GApplication* application,
    GVariant* platform_data
  );
  void (* after_emit) (
    GApplication* application,
    GVariant* platform_data
  );
  void (* add_platform_data) (
    GApplication* application,
    GVariantBuilder* builder
  );
  void (* quit_mainloop) (
    GApplication* application
  );
  void (* run_mainloop) (
    GApplication* application
  );
  void (* shutdown) (
    GApplication* application
  );
  gboolean (* dbus_register) (
    GApplication* application,
    GDBusConnection* connection,
    const gchar* object_path,
    GError** error
  );
  void (* dbus_unregister) (
    GApplication* application,
    GDBusConnection* connection,
    const gchar* object_path
  );
  gint (* handle_local_options) (
    GApplication* application,
    GVariantDict* options
  );
  gboolean (* name_lost) (
    GApplication* application
  );
  
}
Class members
startup
void (* startup) (
    GApplication* application
  )
  No description available.
activate
void (* activate) (
    GApplication* application
  )
  No description available.
open
void (* open) (
    GApplication* application,
    GFile** files,
    gint n_files,
    const gchar* hint
  )
  No description available.
command_line
int (* command_line) (
    GApplication* application,
    GApplicationCommandLine* command_line
  )
  No description available.
local_command_line
gboolean (* local_command_line) (
    GApplication* application,
    gchar*** arguments,
    int* exit_status
  )
  No description available.
before_emit
void (* before_emit) (
    GApplication* application,
    GVariant* platform_data
  )
  No description available.
after_emit
void (* after_emit) (
    GApplication* application,
    GVariant* platform_data
  )
  No description available.
add_platform_data
void (* add_platform_data) (
    GApplication* application,
    GVariantBuilder* builder
  )
  No description available.
quit_mainloop
void (* quit_mainloop) (
    GApplication* application
  )
  No description available.
run_mainloop
void (* run_mainloop) (
    GApplication* application
  )
  No description available.
shutdown
void (* shutdown) (
    GApplication* application
  )
  No description available.
dbus_register
gboolean (* dbus_register) (
    GApplication* application,
    GDBusConnection* connection,
    const gchar* object_path,
    GError** error
  )
  No description available.
dbus_unregister
void (* dbus_unregister) (
    GApplication* application,
    GDBusConnection* connection,
    const gchar* object_path
  )
  No description available.
handle_local_options
gint (* handle_local_options) (
    GApplication* application,
    GVariantDict* options
  )
  No description available.
name_lost
gboolean (* name_lost) (
    GApplication* application
  )
  No description available.

Virtual methods

Gio.ApplicationClass.activate

Activates the application.

Available since: 2.28

Gio.ApplicationClass.add_platform_data
No description available.
Gio.ApplicationClass.after_emit
No description available.
Gio.ApplicationClass.before_emit
No description available.
Gio.ApplicationClass.command_line
No description available.
Gio.ApplicationClass.dbus_register
No description available.
Gio.ApplicationClass.dbus_unregister
No description available.
Gio.ApplicationClass.handle_local_options
No description available.
Gio.ApplicationClass.local_command_line

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).

Gio.ApplicationClass.name_lost
No description available.
Gio.ApplicationClass.open

Opens the given files.

Available since: 2.28

Gio.ApplicationClass.quit_mainloop
No description available.
Gio.ApplicationClass.run_mainloop
No description available.
Gio.ApplicationClass.shutdown
No description available.
Gio.ApplicationClass.startup
No description available.