watch
open fun watch(this: <Error class: unknown class>? = null, notify: ExpressionNotify): ExpressionWatch
Watch the given expression for changes.
The @notify function will be called whenever the evaluation of self may have changed.
GTK cannot guarantee that the evaluation did indeed change when the @notify gets invoked, but it guarantees the opposite: When it did in fact change, the @notify will be invoked.
Return
The newly installed watch. Note that the only reference held to the watch will be released when the watch is unwatched which can happen automatically, and not just via method@Gtk.ExpressionWatch.unwatch. You should call method@Gtk.ExpressionWatch.ref if you want to keep the watch around.
Parameters
this
the this argument to watch
notify
callback to invoke when the expression changes