### Class

# Gtk Application

#### Description [src]

    class Gtk.Application : Gio.Application {
      parent_instance: GApplication
    }

`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 `GtkWindow`s, it is recommended to use it together with `GtkApplicationWindow`.

## 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 `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 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 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 gtk_icon_theme_add_resource_path() for more information.

If there is a resource located at “gtk/help-overlay.ui” which defines a `GtkShortcutsWindow` with ID “help_overlay” then `GtkApplication` associates an instance of this shortcuts window with each `GtkApplicationWindow` and sets up the keyboard accelerator `Control`+`?` 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 `GtkApplication: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 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, Getting Started with GTK: Basics.

#### Hierarchy

#### Ancestors

- GApplication
- GObject

#### Implements

- GActionGroup
- GActionMap

#### Constructors

###### gtk_application_new

Creates a new `GtkApplication` instance.

#### Instance methods

###### gtk_application_add_window

Adds a window to `application`.

###### gtk_application_get_accels_for_action

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

###### gtk_application_get_actions_for_accel

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

###### gtk_application_get_active_window

Gets the “active” window for the application.

###### gtk_application_get_menu_by_id

Gets a menu from automatically loaded resources.

###### gtk_application_get_menubar

Returns the menu model that has been set with gtk_application_set_menubar().

###### gtk_application_get_window_by_id

Returns the `GtkApplicationWindow` with the given ID.

###### gtk_application_get_windows

Gets a list of the `GtkWindow` instances associated with `application`.

###### gtk_application_inhibit

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

###### gtk_application_list_action_descriptions

Lists the detailed action names which have associated accelerators.

###### gtk_application_remove_window

Remove a window from `application`.

###### gtk_application_set_accels_for_action

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

###### gtk_application_set_menubar

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

###### gtk_application_uninhibit

Removes an inhibitor that has been previously established.

#### Properties

###### Gtk.Application:active-window

The currently focused window of the application.

###### Gtk.Application:menubar

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

###### Gtk.Application:register-session

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

###### Gtk.Application:screensaver-active

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

#### Signals

###### Gtk.Application::query-end

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

###### Gtk.Application::window-added

Emitted when a `GtkWindow` is added to `application` through gtk_application_add_window().

###### Gtk.Application::window-removed

Emitted when a `GtkWindow` is removed from `application`.

#### Class structure

    struct GtkApplicationClass {
      GApplicationClass parent_class;
      void (* window_added) (
        GtkApplication* application,
        GtkWindow* window
      );
      void (* window_removed) (
        GtkApplication* application,
        GtkWindow* window
      );

    }

###### Class members

`parent_class` |
    GApplicationClass
| The parent class.
`window_added` |
    void (* window_added) (
        GtkApplication* application,
        GtkWindow* window
      )
| No description available.
`window_removed` |
    void (* window_removed) (
        GtkApplication* application,
        GtkWindow* window
      )
| No description available.

#### Virtual methods

###### Gtk.ApplicationClass.window_added

No description available.

###### Gtk.ApplicationClass.window_removed

No description available.