Gio.Application

class — extends GObject.Object, ActionGroup, ActionMap

GApplication is the core class for application support.

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 Application.hold and 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 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 Application.run promptly returns. See the code examples below.

If used, the expected form of an application identifier is the same as that 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 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 Application attempts to acquire the bus name of your application (which happens in Application.register). Unfortunately, this means that you cannot use Application.is-remote to decide if you want to register object paths.

GApplication also implements the ActionGroup and ActionMap interfaces and lets you easily export actions by adding them with ActionMap.add_action. When invoking an action by calling ActionGroup.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 DBusActionGroup wrapper to conveniently access them remotely. GIO provides a DBusMenuModel wrapper for remote access to exported MenuModels.

Note: Due to the fact that actions are exported on the session bus, using maybe parameters is not supported, since D-Bus does not support maybe types.

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 Application.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 GLib.Variant dictionary mapping strings to variants. To use platform data, override the Application.before_emit or Application.after_emit virtual functions in your GApplication subclass. When dealing with ApplicationCommandLine objects, the platform data is directly available via ApplicationCommandLine.get_cwd, ApplicationCommandLine.get_environ and ApplicationCommandLine.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 Application.add_platform_data virtual function. For instance, GtkApplication adds startup notification data in this way.

To parse commandline arguments you may handle the Application.command-line signal or override the Application.local_command_line virtual function, 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.

Constructors

new

@classmethod
def new(cls, application_id: str | None, flags: ApplicationFlags | int) -> Application

Creates a new Application instance.

If non-None, the application id must be valid. See Application.id_is_valid.

If no application ID is given then some features of Application (most notably application uniqueness) will be disabled.

Parameters:

• application_id — the application id
• flags — the application flags

Methods

activate

def activate(self) -> None

Activates the application.

In essence, this results in the Application::activate signal being emitted in the primary instance.

The application must be registered before calling this function.

add_main_option

def add_main_option(self, long_name: str, short_name: int, flags: GLib.OptionFlags | int, arg: GLib.OptionArg | int, description: str, arg_description: str | None = ...) -> None

Add an option to be handled by application.

Calling this function is the equivalent of calling Application.add_main_option_entries with a single GLib.OptionEntry that has its arg_data member set to None.

The parsed arguments will be packed into a GLib.VariantDict which is passed to Application::handle-local-options. If ApplicationFlags.HANDLES_COMMAND_LINE is set, then it will also be sent to the primary instance. See Application.add_main_option_entries for more details.

See GLib.OptionEntry for more documentation of the arguments.

Parameters:

• long_name — the long name of an option used to specify it in a commandline
• short_name — the short name of an option
• flags — flags from GLib.OptionFlags
• arg — the type of the option, as a GLib.OptionArg
• description — the description for the option in --help output
• arg_description — the placeholder to use for the extra argument parsed by the option in --help output

add_main_option_entries

def add_main_option_entries(self, entries: list[GLib.OptionEntry]) -> None

Adds main option entries to be handled by application.

This function is comparable to GLib.OptionContext.add_main_entries.

After the commandline arguments are parsed, the Application::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 GLib.OptionContext, Application supports giving a None arg_data for a non-callback GLib.OptionEntry. This results in the argument in question being packed into a GLib.VariantDict which is also passed to Application::handle-local-options, where it can be inspected and modified. If ApplicationFlags.HANDLES_COMMAND_LINE is set, then the resulting dictionary is sent to the primary instance, where ApplicationCommandLine.get_options_dict will return it. As it has been passed outside the process at this point, the types of all values in the options dict must be checked before being used. 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" GLib.Variant 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. Application ignored them completely on the local side. Calling this function "opts in" to the new behaviour, and in particular, means that unrecognized options will be treated as errors. Unrecognized options have never been ignored when ApplicationFlags.HANDLES_COMMAND_LINE is unset.

If Application::handle-local-options needs to see the list of filenames, then the use of GLib.OPTION_REMAINING is recommended. If arg_data is None then GLib.OPTION_REMAINING can be used as a key into the options dictionary. If you do use GLib.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(): - for GLib.OptionArg.NONE, use b - for GLib.OptionArg.STRING, use &s - for GLib.OptionArg.INT, use i - for GLib.OptionArg.INT64, use x - for GLib.OptionArg.DOUBLE, use d - for GLib.OptionArg.FILENAME, use ^&ay - for GLib.OptionArg.STRING_ARRAY, use ^a&s - for GLib.OptionArg.FILENAME_ARRAY, use ^a&ay

Parameters:

• entries — the main options for the application

add_option_group

def add_option_group(self, group: GLib.OptionGroup) -> None

Adds a GLib.OptionGroup to the commandline handling of application.

This function is comparable to GLib.OptionContext.add_group.

Unlike Application.add_main_option_entries, this function does not deal with None 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 Application::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 GLib.OptionGroup 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 unrecognized options are rejected even if ApplicationFlags.HANDLES_COMMAND_LINE was given.

Parameters:

• group — a GLib.OptionGroup

bind_busy_property

def bind_busy_property(self, object: GObject.Object, property: str) -> None

Marks application as busy (see 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.

Parameters:

• object — a GObject.Object
• property — the name of a boolean property of object

get_application_id

def get_application_id(self) -> str | None

Gets the unique identifier for application.

get_dbus_connection

def get_dbus_connection(self) -> DBusConnection | None

Gets the DBusConnection being used by the application, or None.

If Application is using its D-Bus backend then this function will return the DBusConnection being used for uniqueness and communication with the desktop environment and other instances of the application.

If Application is not using D-Bus then this function will return None. 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 Application.get_is_registered.

get_dbus_object_path

def get_dbus_object_path(self) -> str | None

Gets the D-Bus object path being used by the application, or None.

If Application is using its D-Bus backend then this function will return the D-Bus object path that Application 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 Application is not using D-Bus then this function will return None. 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 Application.get_is_registered.

get_flags

def get_flags(self) -> ApplicationFlags

Gets the flags for application.

See ApplicationFlags.

get_inactivity_timeout

def get_inactivity_timeout(self) -> int

Gets the current inactivity timeout for the application.

This is the amount of time (in milliseconds) after the last call to Application.release before the application stops running.

get_is_busy

def get_is_busy(self) -> bool

Gets the application's current busy state, as set through Application.mark_busy or Application.bind_busy_property.

get_is_registered

def get_is_registered(self) -> bool

Checks if application is registered.

An application is registered if Application.register has been successfully called.

get_is_remote

def get_is_remote(self) -> bool

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 Application.register has been called. See Application.get_is_registered.

get_resource_base_path

def get_resource_base_path(self) -> str | None

Gets the resource base path of application.

See Application.set_resource_base_path for more information.

get_version

def get_version(self) -> str | None

Gets the version of application.

hold

def hold(self) -> None

Increases the use count of application.

Use this function to indicate that the application has a reason to continue to run. For example, Application.hold is called by GTK when a toplevel window is on the screen.

To cancel the hold, call Application.release.

mark_busy

def mark_busy(self) -> None

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 Application.unmark_busy.

The application must be registered before calling this function.

open

def open(self, files: list[File], hint: str) -> None

Opens the given files.

In essence, this results in the Application::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 ApplicationFlags.HANDLES_OPEN flag set.

Parameters:

• files — an array of GFiles to open
• hint — a hint (or ""), but never None

quit

def quit(self) -> None

Immediately quits the application.

Upon return to the mainloop, Application.run will return, calling only the 'shutdown' function before doing so.

The hold count is ignored. Take care if your code has called Application.hold on the application and is therefore still expecting it to exist. (Note that you may have called Application.hold indirectly, for example through Gtk.Application.add_window.)

The result of calling Application.run again after it returns is unspecified.

register

def register(self, cancellable: Cancellable | None = ...) -> bool

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 ApplicationFlags.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 Application::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 Application.get_is_remote for that.

Parameters:

• cancellable — a Cancellable, or None

release

def release(self) -> None

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 Application.hold.

run

def run(self, argv: list[str | bytes | os.PathLike[str] | os.PathLike[bytes]] | None = ...) -> int

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 None 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).

Application will attempt to parse the commandline arguments. You can add commandline flags to the list of recognised options by way of Application.add_main_option_entries. After this, the Application::handle-local-options signal is emitted, from which the application can inspect the values of its GOptionEntrys.

Application::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 Application::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 ApplicationFlags.HANDLES_COMMAND_LINE was specified then the remaining commandline arguments are sent to the primary instance, where a Application::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 Application::activate signal. If there are one or more files, and ApplicationFlags.HANDLES_OPEN was specified then the files are opened via the Application::open signal.

If you are interested in doing more complicated local handling of the commandline then you should implement your own Application 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 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 ApplicationFlags.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 Application.set_inactivity_timeout is in use.

This function sets the prgname (GLib.set_prgname), if not already set, to the basename of argv[0].

Much like GLib.MainLoop.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 ApplicationFlags.IS_SERVICE or ApplicationFlags.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 ApplicationFlags.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.

Parameters:

• argv — the argv from main(), or None

send_notification

def send_notification(self, id: str | None, notification: Notification) -> None

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 Application.withdraw_notification.

It is an error to call this function if application has no application ID.

Parameters:

• id — id of the notification, or None
• notification — the Notification to send

set_action_group

def set_action_group(self, action_group: ActionGroup | None = ...) -> None

:::warning Deprecated since 2.32 This API is deprecated. :::

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

Parameters:

• action_group — a ActionGroup, or None

set_application_id

def set_application_id(self, application_id: str | None = ...) -> None

Sets the unique identifier for application.

The application id can only be modified if application has not yet been registered.

If non-None, the application id must be valid. See Application.id_is_valid.

Parameters:

• application_id — the identifier for application

set_default

def set_default(self) -> None

Sets or unsets the default application for the process, as returned by 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 None.

set_flags

def set_flags(self, flags: ApplicationFlags | int) -> None

Sets the flags for application.

The flags can only be modified if application has not yet been registered.

See ApplicationFlags.

Parameters:

• flags — the flags for application

set_inactivity_timeout

def set_inactivity_timeout(self, inactivity_timeout: int) -> None

Sets the current inactivity timeout for the application.

This is the amount of time (in milliseconds) after the last call to 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 Application.release drops the use count to zero. Any timeouts currently in progress are not impacted.

Parameters:

• inactivity_timeout — the timeout, in milliseconds

set_option_context_description

def set_option_context_description(self, description: str | None = ...) -> None

Adds a description to the application option context.

See GLib.OptionContext.set_description for more information.

Parameters:

• description — a string to be shown in --help output after the list of options, or None

set_option_context_parameter_string

def set_option_context_parameter_string(self, parameter_string: str | None = ...) -> None

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 GLib.OptionContext of application is created.

See g_option_context_new() for more information about parameter_string.

Parameters:

• parameter_string — a string which is displayed in the first line of --help output, after the usage summary programname [OPTION...].

set_option_context_summary

def set_option_context_summary(self, summary: str | None = ...) -> None

Adds a summary to the application option context.

See GLib.OptionContext.set_summary for more information.

Parameters:

• summary — a string to be shown in --help output before the list of options, or None

set_resource_base_path

def set_resource_base_path(self, resource_path: str | None = ...) -> None

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

The path is used to automatically load various [application resources]Resource 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 Application 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 Gtk.Application (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 Resource for more information about adding resources to your application.

You can disable automatic resource loading functionality by setting the path to None.

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 Application you should either set the Application:resource-base-path property at construction time, or call this function during the instance initialization. Alternatively, you can call this function in the ApplicationClass.startup virtual function, before chaining up to the parent implementation.

Parameters:

• resource_path — the resource path to use

set_version

def set_version(self, version: str) -> None

Sets the version number of application. This will be used to implement a --version command line argument

The application version can only be modified if application has not yet been registered.

Parameters:

• version — the version of application

unbind_busy_property

def unbind_busy_property(self, object: GObject.Object, property: str) -> None

Destroys a binding between property and the busy state of application that was previously created with Application.bind_busy_property.

Parameters:

• object — a GObject.Object
• property — the name of a boolean property of object

unmark_busy

def unmark_busy(self) -> None

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 Application.mark_busy.

withdraw_notification

def withdraw_notification(self, id: str) -> None

Withdraws a notification that was sent with 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.

Parameters:

• id — id of a previously sent notification

Static functions

get_default

@staticmethod
def get_default() -> Application | None

Returns the default Application instance for this process.

Normally there is only one Application per process and it becomes the default when it is created. You can exercise more control over this by using Application.set_default.

If there is no default application then None is returned.

id_is_valid

@staticmethod
def id_is_valid(application_id: str) -> bool

Checks if application_id is a valid application identifier.

A valid ID is required for calls to Application.new and 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.

Parameters:

• application_id — a potential application identifier

Virtual methods

do_activate

def do_activate(self) -> None

Activates the application.

In essence, this results in the Application::activate signal being emitted in the primary instance.

The application must be registered before calling this function.

do_add_platform_data

def do_add_platform_data(self, builder: GLib.VariantBuilder) -> None

invoked (locally) to add 'platform data' to be sent to the primary instance when activating, opening or invoking actions. Must chain up

do_after_emit

def do_after_emit(self, platform_data: GLib.Variant) -> None

invoked on the primary instance after 'activate', 'open', 'command-line' or any action invocation, gets the 'platform data' from the calling instance. Must chain up

do_before_emit

def do_before_emit(self, platform_data: GLib.Variant) -> None

invoked on the primary instance before 'activate', 'open', 'command-line' or any action invocation, gets the 'platform data' from the calling instance. Must chain up

do_command_line

def do_command_line(self, command_line: ApplicationCommandLine) -> int

invoked on the primary instance when a command-line is not handled locally

do_dbus_register

def do_dbus_register(self, connection: DBusConnection, object_path: str) -> bool

invoked locally during registration, if the application is using its D-Bus backend. You can use this to export extra objects on the bus, that need to exist before the application tries to own the bus name. The function is passed the DBusConnection to to session bus, and the object path that Application will use to export its D-Bus API. If this function returns True, registration will proceed; otherwise registration will abort. Since: 2.34

do_dbus_unregister

def do_dbus_unregister(self, connection: DBusConnection, object_path: str) -> None

invoked locally during unregistration, if the application is using its D-Bus backend. Use this to undo anything done by the dbus_register vfunc. Since: 2.34

do_handle_local_options

def do_handle_local_options(self, options: GLib.VariantDict) -> int

invoked locally after the parsing of the commandline options has occurred. Since: 2.40

do_local_command_line

def do_local_command_line(self, arguments: list[str]) -> tuple[bool, list[str], int]

This virtual function is always invoked in the local instance. It gets passed a pointer to a None-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 Application.run.

See Application.run for more details on Application startup.

Parameters:

• arguments — array of command line arguments

do_name_lost

def do_name_lost(self) -> bool

invoked when another instance is taking over the name. Since: 2.60

do_open

def do_open(self, files: list[File], hint: str) -> None

Opens the given files.

In essence, this results in the Application::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 ApplicationFlags.HANDLES_OPEN flag set.

Parameters:

• files — an array of GFiles to open
• hint — a hint (or ""), but never None

do_quit_mainloop

def do_quit_mainloop(self) -> None

Used to be invoked on the primary instance when the use count of the application drops to zero (and after any inactivity timeout, if requested). Not used anymore since 2.32

do_run_mainloop

def do_run_mainloop(self) -> None

Used to be invoked on the primary instance from Application.run if the use-count is non-zero. Since 2.32, GApplication is iterating the main context directly and is not using run_mainloop anymore

do_shutdown

def do_shutdown(self) -> None

invoked only on the registered primary instance immediately after the main loop terminates

do_startup

def do_startup(self) -> None

invoked on the primary instance immediately after registration

Properties

action_group

action_group: ActionGroup  # read/write

:::warning Deprecated since 2.32 This API is deprecated. :::

The group of actions that the application exports.

application_id

application_id: str  # read/write

The unique identifier for the application.

flags

flags: ApplicationFlags | int  # read/write

Flags specifying the behaviour of the application.

inactivity_timeout

inactivity_timeout: int  # read/write

Time (in milliseconds) to stay alive after becoming idle.

is_busy

is_busy: bool  # read-only

Whether the application is currently marked as busy through Application.mark_busy or Application.bind_busy_property.

is_registered

is_registered: bool  # read-only

Whether Application.register has been called.

is_remote

is_remote: bool  # read-only

Whether this application instance is remote.

resource_base_path

resource_base_path: str  # read/write

The base resource path for the application.

version

version: str  # read/write

The human-readable version number of the application.

Signals

activate

def on_activate(self) -> None: ...

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

command-line

def on_command_line(self, command_line: ApplicationCommandLine) -> int: ...

The ::command-line signal is emitted on the primary instance when a commandline is not handled locally. See Application.run and the ApplicationCommandLine documentation for more information.

handle-local-options

def on_handle_local_options(self, options: GLib.VariantDict) -> int: ...

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

You can add options to be recognised during commandline option parsing using Application.add_main_option_entries and Application.add_option_group.

Signal handlers can inspect options (along with values pointed to from the arg_data of an installed GOptionEntrys) in order to decide to perform certain actions, including direct local handling (which may be useful for options like --version).

In the event that the application is marked ApplicationFlags.HANDLES_COMMAND_LINE the "normal processing" will send the options dictionary to the primary instance where it can be read with ApplicationCommandLine.get_options_dict. The signal handler can modify the dictionary before returning, and the modified dictionary will be sent.

In the event that ApplicationFlags.HANDLES_COMMAND_LINE is not set, "normal processing" will treat the remaining uncollected command line arguments as filenames or URIs. If there are no arguments, the application is activated by Application.activate. One or more arguments results in a call to Application.open.

If you want to handle the local commandline arguments for yourself by converting them to calls to Application.open or ActionGroup.activate_action then you must be sure to register the application first. You should probably not call Application.activate for yourself, however: just return -1 and allow the default handler to do it for you. This will ensure that the --gapplication-service switch works properly (i.e. no activation in that case).

Note that this signal is emitted from the default implementation of local_command_line(). If you override that function and don't chain up then this signal will never be emitted.

You can override local_command_line() if you need more powerful capabilities than what is provided here, but this should not normally be required.

name-lost

def on_name_lost(self) -> bool: ...

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 ApplicationFlags.ALLOW_REPLACEMENT flag.

The default handler for this signal calls Application.quit.

open

def on_open(self, files: list[File], hint: str) -> None: ...

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

shutdown

def on_shutdown(self) -> None: ...

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

startup

def on_startup(self) -> None: ...

The ::startup signal is emitted on the primary instance immediately after registration. See Application.register.