feat: word and char count (#4705)

* feat: word and char count

* chore: lints after merge

* feat: add create time of view in more action

* fix: missing comma lint

* feat: add duplicate/delete + database view more

* fix: dispose logic

* feat: code cleanup

* fix: add false for isDocument in databases

* feat: register view info bloc on plugin basis

* fix: accidental removal

* chore: clean up

* fix: add ViewInfoBloc above Row Document Editor

* chore: final clean up

frontend/appflowy_flutter/lib/workspace/application/view_info/view_info_bloc.dart

@@ -0,0 +1,87 @@
+import 'package:appflowy/util/int64_extension.dart';
+import 'package:appflowy_backend/protobuf/flowy-folder/view.pb.dart';
+import 'package:appflowy_editor/appflowy_editor.dart';
+import 'package:bloc/bloc.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'view_info_bloc.freezed.dart';
+
+class ViewInfoBloc extends Bloc<ViewInfoEvent, ViewInfoState> {
+  ViewInfoBloc({required this.view}) : super(ViewInfoState.initial()) {
+    on<ViewInfoEvent>((event, emit) {
+      event.when(
+        started: () {
+          emit(state.copyWith(createdAt: view.createTime.toDateTime()));
+        },
+        unregisterEditorState: () {
+          _clearWordCountService();
+          emit(state.copyWith(documentCounters: null));
+        },
+        registerEditorState: (editorState) {
+          _clearWordCountService();
+          _wordCountService = WordCountService(editorState: editorState)
+            ..addListener(_onWordCountChanged)
+            ..register();
+
+          emit(
+            state.copyWith(
+              documentCounters: _wordCountService!.documentCounters,
+            ),
+          );
+        },
+        wordCountChanged: () {
+          emit(
+            state.copyWith(
+              documentCounters: _wordCountService?.documentCounters,
+            ),
+          );
+        },
+      );
+    });
+  }
+
+  final ViewPB view;
+
+  WordCountService? _wordCountService;
+
+  @override
+  Future<void> close() async {
+    _clearWordCountService();
+    await super.close();
+  }
+
+  void _onWordCountChanged() => add(const ViewInfoEvent.wordCountChanged());
+
+  void _clearWordCountService() {
+    _wordCountService
+      ?..removeListener(_onWordCountChanged)
+      ..dispose();
+    _wordCountService = null;
+  }
+}
+
+@freezed
+class ViewInfoEvent with _$ViewInfoEvent {
+  const factory ViewInfoEvent.started() = _Started;
+
+  const factory ViewInfoEvent.unregisterEditorState() = _UnregisterEditorState;
+
+  const factory ViewInfoEvent.registerEditorState({
+    required EditorState editorState,
+  }) = _RegisterEditorState;
+
+  const factory ViewInfoEvent.wordCountChanged() = _WordCountChanged;
+}
+
+@freezed
+class ViewInfoState with _$ViewInfoState {
+  const factory ViewInfoState({
+    required Counters? documentCounters,
+    required DateTime? createdAt,
+  }) = _ViewInfoState;
+
+  factory ViewInfoState.initial() => const ViewInfoState(
+        documentCounters: null,
+        createdAt: null,
+      );
+}