Application.this
(string applicationId, gio.types.ApplicationFlags flags)Creates a new #GtkApplication instance.
When using #GtkApplication, it is not necessary to call [gtk.global.init_] manually. It is called as soon as the application gets registered as the primary instance.
Concretely, [gtk.global.init_] is called in the default handler for the #GApplication::startup signal. Therefore, #GtkApplication subclasses should chain up in their #GApplication::startup handler before using any GTK+ API.
Note that commandline arguments are not passed to [gtk.global.init_]. All GTK+ functionality that is available via commandline arguments can also be achieved by setting suitable environment variables such as G_DEBUG, so this should not be a big problem. If you absolutely must support GTK+ commandline arguments, you can explicitly call [gtk.global.init_] before creating the application instance.
If non-null, the application ID must be valid. See [gio.application.Application.idIsValid].
If no application ID is given then some features (most notably application uniqueness) will be disabled. A null application ID is only allowed with GTK+ 3.6 or later.
Parameters
applicationId | The application ID. |
flags | the application flags |