It supports many aspects of writing a GTK application in a convenient
fashion, without enforcing a one-size-fits-all model.
Currently, gtk.application.Application 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.
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.
gtk.application.Application 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.IconTheme.addResourcePath for more
information.
If there is a resource located at gtk/help-overlay.ui which
defines a gtk.shortcuts_window.ShortcutsWindow with ID help_overlay then
gtk.application.Application associates an instance of this shortcuts window with
each gtk.application_window.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.
gtk.application.Application 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 gtk.application.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.
gtk.application.Application 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, gtk.application.Application 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 gtk.application.Application works fine with plain gtk.window.Windows, it is recommended to use it together with gtk.application_window.ApplicationWindow.
Automatic resources
gtk.application.Application will automatically load menus from the gtk.builder.Builder resource located at "gtk/menus.ui", relative to the application's resource base path (see gio.application.Application.setResourceBasePath). 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.Application.getMenuById 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 gtk.application.Application.setMenubar.
gtk.application.Application 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.IconTheme.addResourcePath for more information.
If there is a resource located at gtk/help-overlay.ui which defines a gtk.shortcuts_window.ShortcutsWindow with ID help_overlay then gtk.application.Application associates an instance of this shortcuts window with each gtk.application_window.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
gtk.application.Application 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 gtk.application.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