Interface

Gio-2.0GioMenuSignalSignatures

interface SignalSignatures {
    "items-changed": (arg0: number, arg1: number, arg2: number) => void;
    notify: (arg0: GObject.ParamSpec) => void;
}

Hierarchy (View Summary)

Index

Properties - Inherited from Gio.MenuModel.SignalSignatures

Properties - Inherited from Gio.MenuModel.SignalSignatures

"items-changed": (arg0: number, arg1: number, arg2: number) => void

Emitted when a change has occurred to the menu.

The only changes that can occur to a menu is that items are removed or added. Items may not change (except by being removed and added back in the same location). This signal is capable of describing both of those changes (at the same time).

The signal means that starting at the index position, removed items were removed and added items were added in their place. If removed is zero then only items were added. If added is zero then only items were removed.

As an example, if the menu contains items a, b, c, d (in that order) and the signal (2, 1, 3) occurs then the new composition of the menu will be a, b, _, _, _, d (with each _ representing some new item).

Signal handlers may query the model (particularly the added items) and expect to see the results of the modification that is being reported. The signal is emitted after the modification.

notify: (arg0: GObject.ParamSpec) => void

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

Note that getting this signal doesn’t itself guarantee that the value of the property has actually changed. When it is emitted is determined by the derived GObject class. If the implementor did not create the property with GObject.ParamFlags.EXPLICIT_NOTIFY, then any call to g_object_set_property() results in ::notify being emitted, even if the new value is the same as the old. If they did pass GObject.ParamFlags.EXPLICIT_NOTIFY, then this signal is emitted only when they explicitly call g_object_notify() or g_object_notify_by_pspec(), and common practice is to do that only when the value has actually changed.

This signal is typically used to obtain change notification for a single property, by specifying the property name as a detail in the g_signal_connect() call, like this:

g_signal_connect (text_view->buffer, "notify::paste-target-list",
G_CALLBACK (gtk_text_view_target_list_notify),
text_view)

It is important to note that you must use [canonical parameter names][class@GObject.ParamSpec#parameter-names] as detail strings for the notify signal.