Widget.connectVisibilityNotifyEvent

Connect to VisibilityNotifyEvent signal.

The ::visibility-notify-event will be emitted when the widget's window is obscured or unobscured.

To receive this signal the #GdkWindow associated to the widget needs to enable the #GDK_VISIBILITY_NOTIFY_MASK mask.

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class Widget
gulong
connectVisibilityNotifyEvent
(
T
)
(,
Flag!"After" after = No.After
)
if (
isCallable!T &&
is(ReturnType!T == bool)
&&
(
Parameters!T.length < 1 ||
(
ParameterStorageClassTuple!T[0] == ParameterStorageClass.none &&
)
)
&&
(
Parameters!T.length < 2 ||
(
ParameterStorageClassTuple!T[1] == ParameterStorageClass.none &&
is(Parameters!T[1] : gtk.widget.Widget)
)
)
&&
Parameters!T.length < 3
)

Parameters

callback T

signal callback delegate or function to connect

bool callback(gdk.event_visibility.EventVisibility event, gtk.widget.Widget widget)

event the #GdkEventVisibility which triggered this signal. (optional)

widget the instance the signal is connected to (optional)

Returns true to stop other handlers from being invoked for the event. false to propagate the event further.

after Flag!"After"

Yes.After to execute callback after default handler, No.After to execute before (default)

Return Value

Type: gulong

Signal ID

Detailed Description

Deprecated: Modern composited windowing systems with pervasive transparency make it impossible to track the visibility of a window reliably, so this signal can not be guaranteed to provide useful information.