public class Application : Application, ActionGroup, 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 [class@Gtk.Window]s, it is recommended to use it together with [class@Gtk.ApplicationWindow].
`GtkApplication` will automatically load menus from the `GtkBuilder` resource located at "gtk/menus.ui", relative to the application's resource base path (see `g_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 [method@Gtk.Application.get_menu_by_id] which allows for dynamic population of a part of the menu structure.
It is also possible to provide the menubar manually using [method@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 [method@Gtk.IconTheme.add_resource_path] for more information.
If there is a resource located at "gtk/help-overlay.ui" which defines a [class@Gtk.ShortcutsWindow] with ID "help_overlay" then `GtkApplication` associates an instance of this shortcuts window with each [class@Gtk.ApplicationWindow] and sets up the keyboard accelerator <kbd>Control</kbd>+<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 is available in the GTK source code repository
`GtkApplication` optionally registers with a session manager of the users session (if you set the [property@Gtk.Application: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 [method@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.
HowDoI: Using GtkApplication, [Getting Started with GTK: Basics]( getting_started.html#basics)