performAction method

@override void performAction(TextInputAction action)

Requests that this client perform the given action.

Implementation

@override
void performAction(TextInputAction action) {
  if (_document == null) return;
  switch (action) {
    case TextInputAction.newline:
      // If the newline was already handled via delta (iOS virtual
      // keyboard often sends both a delta and a performAction),
      // skip the second enter to avoid double-splitting.
      if (_justHandledEnter) {
        _justHandledEnter = false;
        break;
      }

      // Start grace period BEFORE the structural change so any platform
      // echo that arrives during the split is ignored.
      _structuralChangeInProgress = true;
      _structuralChangeTimer?.cancel();

      // Commit any pending preedit first, then handle enter.
      commitIfComposing();
      _document!.saveState(description: 'Enter', forceNewAction: true);
      executeHandleEnter(_document!);

      // Sync the IME buffer with the NEW fragment text so the platform
      // computes subsequent deltas against the correct content. On iOS
      // this also injects the zero-width placeholder when the cursor is
      // at offset 0, preventing Backspace from being swallowed.
      _lastSyncedFragmentId = _document!.cursor.focusId.isNotEmpty
          ? _document!.cursor.focusId
          : _document!.cursor.anchorId;
      syncImeBufferToFragment();

      _structuralChangeTimer = Timer(_structuralChangeGracePeriod, () {
        _structuralChangeInProgress = false;
      });
      break;
    case TextInputAction.go:
    case TextInputAction.send:
    case TextInputAction.done:
      commitIfComposing();
      break;
    default:
      break;
  }
}