Vdom.Eventtype t = Ui_event.t = ..type t += | IgnoreIgnore events are dropped, so no handler is called
| Viewport_changedViewport_changed events are delivered to all visibility handlers
| Stop_propagationStop_propagation prevents the underlying DOM event from propagating up to the parent elements
| Prevent_defaultPrevent_default prevents the default browser action from occurring as a result of this event
| Many of t listAllows one to represent a list of handlers, which will be individually dispatched to their respective handlers. This is so callbacks can return multiple events of whatever kind.
*)module type Handler = sig ... endmodule type Visibility_handler = sig ... endmodule type S = sig ... endFor registering a new handler and a corresponding new constructor of the Event.t type
module Define_visibility (VH : Visibility_handler) : sig ... endFor registering a handler for Viewport_changed events. Note that if this functor is called multiple times, each handler will see all of the events.
module Expert : sig ... end