sendEvent method

void sendEvent (SemanticsEvent event)

Sends a SemanticsEvent associated with this SemanticsNode.

Semantics events should be sent to inform interested parties (like the accessibility system of the operating system) about changes to the UI.

For example, if this semantics node represents a scrollable list, a ScrollCompletedSemanticsEvent should be sent after a scroll action is completed. That way, the operating system can give additional feedback to the user about the state of the UI (e.g. on Android a ping sound is played to indicate a successful scroll in accessibility mode).

Implementation 

void sendEvent(SemanticsEvent event) {
  if (!attached)
    return;
  SystemChannels.accessibility.send(event.toMap(nodeId: id));
}