The event will be sent to all controls on the current page hierarchy.
If a control defines the event, the event will be raised for the control.
If a control implements {@link IBroadcastEventReceiver}, its
{@link IBroadcastEventReceiver::broadcastEventReceived broadcastEventReceived()} method will
be invoked which gives the control a chance to respond to the event.
For example, when broadcasting event 'OnClick', all controls having 'OnClick'
event will have this event raised, and all controls implementing
{@link IBroadcastEventReceiver} will also have its
{@link IBroadcastEventReceiver::broadcastEventReceived broadcastEventReceived()}
invoked.