addListener method
Add event listener that will get called when the tracker emits an event.
Implementation
void addListener(Function callback) {
if (_controller.isClosed) {
throw StateError('Closed.');
}
_callbacks.add(callback);
}
Add event listener that will get called when the tracker emits an event.
void addListener(Function callback) {
if (_controller.isClosed) {
throw StateError('Closed.');
}
_callbacks.add(callback);
}