capturePrimary method
void
capturePrimary()
Snapshot the current engine selection into primary. Notifies only on change so a redundant capture (e.g. tap after a tap) doesn't churn the listener chain.
Implementation
void capturePrimary() {
final t = _engine?.selectionText() ?? '';
if (t != _primary) {
_primary = t;
notifyListeners();
}
}