fltkeep-note_editor.dart

// The editor of a [Note], also shows every detail about a single note.
class NoteEditor extends StatefulWidget {
  /// Create a [NoteEditor],
  /// provides an existed [note] in edit mode, or `null` to create a new one.
  const NoteEditor({Key key, this.note}) : super(key: key);

  final Note note;

  @override
  State<StatefulWidget> createState() => _NoteEditorState(note);
}

class _NoteEditorState extends State<NoteEditor> {
  _NoteEditorState(Note note)
    : this._note = note ?? Note(),
    _originNote = note?.copy() ?? Note(),
    this._titleTextController = TextEditingController(text: note?.title),
    this._contentTextController = TextEditingController(text: note?.content);
  ...
  
  /// Returns `true` if the note is modified.
  bool get _isDirty => _note != _originNote;
  ...
}