:right-sidebar: True

Application
===================================================================

.. currentmodule:: gi.repository.Gtk





.. class:: Application(**properties: ~typing.Any)
   :no-contents-entry:


Superclasses: :class:`~gi.repository.Gio.Application`, :class:`~gi.repository.GObject.Object`



Implemented Interfaces: :class:`~gi.repository.Gio.ActionGroup`, :class:`~gi.repository.Gio.ActionMap`



``GtkApplication`` is a high-level API for writing applications.

It supports many aspects of writing a GTK application in a convenient
fashion, without enforcing a one-size-fits-all model.

Currently, ``GtkApplication`` handles GTK initialization, application
uniqueness, session management, provides some basic scriptability and
desktop shell integration by exporting actions and menus and manages a
list of toplevel windows whose life-cycle is automatically tied to the
life-cycle of your application.

While ``GtkApplication`` works fine with plain :obj:`~gi.repository.Gtk.Window`'s, it is
recommended to use it together with :obj:`~gi.repository.Gtk.ApplicationWindow`.

Automatic resources
-------------------

``GtkApplication`` will automatically load menus from the ``GtkBuilder``
resource located at "gtk/menus.ui", relative to the application's
resource base path (see :obj:`~gi.repository.Gio.Application.set_resource_base_path`).
The menu with the ID "menubar" is taken as the application's
menubar. Additional menus (most interesting submenus) can be named
and accessed via :obj:`~gi.repository.Gtk.Application.get_menu_by_id` which allows for
dynamic population of a part of the menu structure.

Note that automatic resource loading uses the resource base path
that is set at construction time and will not work if the resource
base path is changed at a later time.

It is also possible to provide the menubar manually using
:obj:`~gi.repository.Gtk.Application.set_menubar`.

``GtkApplication`` will also automatically setup an icon search path for
the default icon theme by appending "icons" to the resource base
path. This allows your application to easily store its icons as
resources. See :obj:`~gi.repository.Gtk.IconTheme.add_resource_path` for more
information.

If there is a resource located at ``gtk/help-overlay.ui`` which
defines a :obj:`~gi.repository.Gtk.ShortcutsWindow` with ID ``help_overlay`` then
``GtkApplication`` associates an instance of this shortcuts window with
each :obj:`~gi.repository.Gtk.ApplicationWindow` and sets up the keyboard accelerator
:kbd:`Control`+<kbd>?</kbd> to open it. To create a menu item that
displays the shortcuts window, associate the item with the action
``win.show-help-overlay``.

A simple application
--------------------

`A simple example <https://gitlab.gnome.org/GNOME/gtk/tree/main/examples/bp/bloatpad.c>`_
is available in the GTK source code repository

``GtkApplication`` optionally registers with a session manager of the
users session (if you set the :obj:`~gi.repository.Gtk.Application.props.register_session`
property) and offers various functionality related to the session
life-cycle.

An application can block various ways to end the session with
the :obj:`~gi.repository.Gtk.Application.inhibit` function. Typical use cases for
this kind of inhibiting are long-running, uninterruptible operations,
such as burning a CD or performing a disk backup. The session
manager may not honor the inhibitor, but it can be expected to
inform the user about the negative consequences of ending the
session while inhibitors are present.

See Also
--------

`HowDoI: Using GtkApplication <https://wiki.gnome.org/HowDoI/GtkApplication>`_,
`Getting Started with GTK: Basics <getting_started.html#basics>`_



Constructors
------------

.. rst-class:: interim-class

.. class:: Application
   :no-index:


   .. classmethod:: new(application_id: str | None, flags: ~gi.repository.Gio.ApplicationFlags) -> ~gi.repository.Gtk.Application

      Creates a new ``GtkApplication`` instance.

      When using ``GtkApplication``, it is not necessary to call :obj:`~gi.repository.Gtk.init`
      manually. It is called as soon as the application gets registered as
      the primary instance.

      Concretely, :obj:`~gi.repository.Gtk.init` is called in the default handler for the
      ``GApplication::startup`` signal. Therefore, ``GtkApplication`` subclasses should
      always chain up in their ``GApplication::startup`` handler before using any GTK
      API.

      Note that commandline arguments are not passed to :obj:`~gi.repository.Gtk.init`.

      If ``application_id`` is not :const:`None`, then it must be valid. See
      ``:func:`~gi.repository.Gio.Gio.Application.id_is_valid```.

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







      :param application_id: The application ID


      :param flags: the application flags









Methods
-------

.. rst-class:: interim-class

.. class:: Application
   :no-index:


   .. method:: add_window(window: ~gi.repository.Gtk.Window) -> None

      Adds a window to ``application``.

      This call can only happen after the ``application`` has started;
      typically, you should add new application windows in response
      to the emission of the ``GApplication::activate`` signal.

      This call is equivalent to setting the :obj:`~gi.repository.Gtk.Window.props.application`
      property of ``window`` to ``application``.

      Normally, the connection between the application and the window
      will remain until the window is destroyed, but you can explicitly
      remove it with :obj:`~gi.repository.Gtk.Application.remove_window`.

      GTK will keep the ``application`` running as long as it has
      any windows.







      :param window: a ``GtkWindow``





   .. method:: get_accels_for_action(detailed_action_name: str) -> list[str]

      Gets the accelerators that are currently associated with
      the given action.







      :param detailed_action_name: a detailed action name, specifying an action
         and target to obtain accelerators for





   .. method:: get_actions_for_accel(accel: str) -> list[str]

      Returns the list of actions (possibly empty) that ``accel`` maps to.

      Each item in the list is a detailed action name in the usual form.

      This might be useful to discover if an accel already exists in
      order to prevent installation of a conflicting accelerator (from
      an accelerator editor or a plugin system, for example). Note that
      having more than one action per accelerator may not be a bad thing
      and might make sense in cases where the actions never appear in the
      same context.

      In case there are no actions for a given accelerator, an empty array
      is returned. ``NULL`` is never returned.

      It is a programmer error to pass an invalid accelerator string.

      If you are unsure, check it with :obj:`~gi.repository.Gtk.accelerator_parse` first.







      :param accel: an accelerator that can be parsed by :obj:`~gi.repository.Gtk.accelerator_parse`





   .. method:: get_active_window() -> ~gi.repository.Gtk.Window | None

      Gets the “active” window for the application.

      The active window is the one that was most recently focused (within
      the application).  This window may not have the focus at the moment
      if another application has it — this is just the most
      recently-focused window within this application.










   .. method:: get_menu_by_id(id: str) -> ~gi.repository.Gio.Menu | None

      Gets a menu from automatically loaded resources.

      See `the section on Automatic resources <class.Application.html#automatic-resources>`_
      for more information.







      :param id: the id of the menu to look up





   .. method:: get_menubar() -> ~gi.repository.Gio.MenuModel | None

      Returns the menu model that has been set with
      :obj:`~gi.repository.Gtk.Application.set_menubar`.










   .. method:: get_window_by_id(id: int) -> ~gi.repository.Gtk.Window | None

      Returns the :obj:`~gi.repository.Gtk.ApplicationWindow` with the given ID.

      The ID of a ``GtkApplicationWindow`` can be retrieved with
      :obj:`~gi.repository.Gtk.ApplicationWindow.get_id`.







      :param id: an identifier number





   .. method:: get_windows() -> list[~gi.repository.Gtk.Window]

      Gets a list of the :obj:`~gi.repository.Gtk.Window` instances associated with ``application``.

      The list is sorted by most recently focused window, such that the first
      element is the currently focused window. (Useful for choosing a parent
      for a transient window.)

      The list that is returned should not be modified in any way. It will
      only remain valid until the next focus change or window creation or
      deletion.










   .. method:: inhibit(window: ~gi.repository.Gtk.Window | None, flags: ~gi.repository.Gtk.ApplicationInhibitFlags, reason: str | None = None) -> int

      Inform the session manager that certain types of actions should be
      inhibited.

      This is not guaranteed to work on all platforms and for all types of
      actions.

      Applications should invoke this method when they begin an operation
      that should not be interrupted, such as creating a CD or DVD. The
      types of actions that may be blocked are specified by the ``flags``
      parameter. When the application completes the operation it should
      call :obj:`~gi.repository.Gtk.Application.uninhibit` to remove the inhibitor. Note
      that an application can have multiple inhibitors, and all of them must
      be individually removed. Inhibitors are also cleared when the
      application exits.

      Applications should not expect that they will always be able to block
      the action. In most cases, users will be given the option to force
      the action to take place.

      The ``reason`` message should be short and to the point.

      If ``window`` is given, the session manager may point the user to
      this window to find out more about why the action is inhibited.







      :param window: a ``GtkWindow``


      :param flags: what types of actions should be inhibited


      :param reason: a short, human-readable string that explains
         why these operations are inhibited





   .. method:: list_action_descriptions() -> list[str]

      Lists the detailed action names which have associated accelerators.

      See :obj:`~gi.repository.Gtk.Application.set_accels_for_action`.










   .. method:: remove_window(window: ~gi.repository.Gtk.Window) -> None

      Remove a window from ``application``.

      If ``window`` belongs to ``application`` then this call is equivalent to
      setting the :obj:`~gi.repository.Gtk.Window.props.application` property of ``window`` to
      ``NULL``.

      The application may stop running as a result of a call to this
      function, if ``window`` was the last window of the ``application``.







      :param window: a ``GtkWindow``





   .. method:: set_accels_for_action(detailed_action_name: str, accels: ~typing.Sequence[str]) -> None

      Sets zero or more keyboard accelerators that will trigger the
      given action.

      The first item in ``accels`` will be the primary accelerator, which may be
      displayed in the UI.

      To remove all accelerators for an action, use an empty, zero-terminated
      array for ``accels``.

      For the ``detailed_action_name``, see ``:func:`~gi.repository.Gio.Action.parse_detailed_name``` and
      ``:func:`~gi.repository.Gio.Action.print_detailed_name```.







      :param detailed_action_name: a detailed action name, specifying an action
         and target to associate accelerators with


      :param accels: a list of accelerators in the format
         understood by :obj:`~gi.repository.Gtk.accelerator_parse`





   .. method:: set_menubar(menubar: ~gi.repository.Gio.MenuModel | None = None) -> None

      Sets or unsets the menubar for windows of ``application``.

      This is a menubar in the traditional sense.

      This can only be done in the primary instance of the application,
      after it has been registered. ``GApplication::startup`` is a good place
      to call this.

      Depending on the desktop environment, this may appear at the top of
      each window, or at the top of the screen.  In some environments, if
      both the application menu and the menubar are set, the application
      menu will be presented as if it were the first item of the menubar.
      Other environments treat the two as completely separate — for example,
      the application menu may be rendered by the desktop shell while the
      menubar (if set) remains in each individual window.

      Use the base ``GActionMap`` interface to add actions, to respond to the
      user selecting these menu items.







      :param menubar: a ``GMenuModel``





   .. method:: uninhibit(cookie: int) -> None

      Removes an inhibitor that has been previously established.

      See :obj:`~gi.repository.Gtk.Application.inhibit`.

      Inhibitors are also cleared when the application exits.







      :param cookie: a cookie that was returned by :obj:`~gi.repository.Gtk.Application.inhibit`









Properties
----------

.. rst-class:: interim-class

.. class:: Application
   :no-index:
   

   .. attribute:: props.active_window
      :type: ~gi.repository.Gtk.Window

      The currently focused window of the application.







   .. attribute:: props.menubar
      :type: ~gi.repository.Gio.MenuModel

      The ``GMenuModel`` to be used for the application's menu bar.







   .. attribute:: props.register_session
      :type: bool

      Set this property to ``TRUE`` to register with the session manager.

      This will make GTK track the session state (such as the
      :obj:`~gi.repository.Gtk.Application.props.screensaver_active` property).







   .. attribute:: props.screensaver_active
      :type: bool

      This property is ``TRUE`` if GTK believes that the screensaver is
      currently active.

      GTK only tracks session state (including this) when
      :obj:`~gi.repository.Gtk.Application.props.register_session` is set to :const:`True`.

      Tracking the screensaver state is currently only supported on
      Linux.











Signals
-------

.. rst-class:: interim-class

.. class:: Application.signals
   :no-index:
   

   .. method:: query_end() -> None

      Emitted when the session manager is about to end the session.

      This signal is only emitted if :obj:`~gi.repository.Gtk.Application.props.register_session`
      is ``TRUE``. Applications can connect to this signal and call
      :obj:`~gi.repository.Gtk.Application.inhibit` with ``GTK_APPLICATION_INHIBIT_LOGOUT``
      to delay the end of the session until state has been saved.










   .. method:: window_added(window: ~gi.repository.Gtk.Window) -> None

      Emitted when a :obj:`~gi.repository.Gtk.Window` is added to ``application`` through
      :obj:`~gi.repository.Gtk.Application.add_window`.







      :param window: the newly-added :obj:`~gi.repository.Gtk.Window`





   .. method:: window_removed(window: ~gi.repository.Gtk.Window) -> None

      Emitted when a :obj:`~gi.repository.Gtk.Window` is removed from ``application``.

      This can happen as a side-effect of the window being destroyed
      or explicitly through :obj:`~gi.repository.Gtk.Application.remove_window`.







      :param window: the :obj:`~gi.repository.Gtk.Window` that is being removed









Virtual Methods
---------------

.. rst-class:: interim-class

.. class:: Application
   :no-index:
   

   .. method:: do_window_added(window: ~gi.repository.Gtk.Window) -> None

      Signal emitted when a ``GtkWindow`` is added to
      application through :func:`~gi.repository.Gtk.Application.add_window`.







      :param window: 




   .. method:: do_window_removed(window: ~gi.repository.Gtk.Window) -> None

      Signal emitted when a ``GtkWindow`` is removed from
      application, either as a side-effect of being destroyed or
      explicitly through :func:`~gi.repository.Gtk.Application.remove_window`.







      :param window: 








Fields
------

.. rst-class:: interim-class

.. class:: Application
   :no-index:
   

   .. attribute:: parent_instance