fix: use enum OTLNavigatorTransition instead of String

lib/pages/course_detail_page.dart

@@ -19,11 +19,9 @@ import 'package:otlplus/widgets/review_block.dart';
 import 'package:otlplus/widgets/review_write_block.dart';
 
 class CourseDetailPage extends StatelessWidget {
-  CourseDetailPage({Key? key, this.fromLectureDetailPage = false})
-      : super(key: key);
+  CourseDetailPage({Key? key}) : super(key: key);
   static String route = 'course_detail_page';
 
-  final bool fromLectureDetailPage;
   final _scrollController = ScrollController();
 
   @override
@@ -326,8 +324,7 @@ class CourseDetailPage extends StatelessWidget {
             return LectureGroupSimpleBlock(
                 lectures: filteredLectures,
                 semester: semester,
-                filter: selectedFilter,
-                fromLectureDetailPage: fromLectureDetailPage);
+                filter: selectedFilter);
           },
         ).toList(),
       ),

lib/pages/lecture_detail_page.dart

@@ -156,19 +156,19 @@ class LectureDetailPage extends StatelessWidget {
     return Row(
       mainAxisAlignment: MainAxisAlignment.end,
       children: <Widget>[
-        Visibility(
-          visible: fromCourseDetailPage == false,
-          child: Padding(
-            padding: EdgeInsets.only(right: 8.0),
-            child: IconTextButton(
-              onTap: () {
+        Padding(
+          padding: EdgeInsets.only(right: 8.0),
+          child: IconTextButton(
+            onTap: () {
+              if (fromCourseDetailPage) {
+                OTLNavigator.pop(context);
+              } else {
                 context.read<CourseDetailModel>().loadCourse(lecture.course);
-                OTLNavigator.push(
-                    context, CourseDetailPage(fromLectureDetailPage: false));
-              },
-              text: "dictionary.dictionary".tr(),
-              textStyle: bodyRegular.copyWith(color: OTLColor.pinksMain),
-            ),
+                OTLNavigator.push(context, CourseDetailPage());
+              }
+            },
+            text: "dictionary.dictionary".tr(),
+            textStyle: bodyRegular.copyWith(color: OTLColor.pinksMain),
           ),
         ),
         IconTextButton(

lib/pages/liked_review_page.dart

@@ -68,7 +68,8 @@ class LikedReviewPage extends StatelessWidget {
                                                 reviews[index].course.id);
                                         OTLNavigator.push(
                                             context, CourseDetailPage(),
-                                            transition: 'right-left');
+                                            transition: OTLNavigatorTransition
+                                                .rightLeft);
                                       },
                                     );
                                   },

lib/pages/main_page.dart

@@ -53,8 +53,8 @@ class _MainPageState extends State<MainPage> {
       trailing: Row(
         children: [
           IconTextButton(
-            onTap: () =>
-                OTLNavigator.push(context, UserPage(), transition: 'down-up'),
+            onTap: () => OTLNavigator.push(context, UserPage(),
+                transition: OTLNavigatorTransition.downUp),
             icon: 'assets/icons/person.svg',
             iconSize: 24,
             color: OTLColor.pinksMain,
@@ -63,7 +63,7 @@ class _MainPageState extends State<MainPage> {
           ),
           IconTextButton(
             onTap: () => OTLNavigator.push(context, SettingsPage(),
-                transition: 'down-up'),
+                transition: OTLNavigatorTransition.downUp),
             icon: 'assets/icons/gear.svg',
             iconSize: 24,
             color: OTLColor.pinksMain,
@@ -241,7 +241,8 @@ class _MainPageState extends State<MainPage> {
       children: [
         IconTextButton(
           onTap: () {
-            OTLNavigator.push(context, PrivacyPage(), transition: 'down-up');
+            OTLNavigator.push(context, PrivacyPage(),
+                transition: OTLNavigatorTransition.downUp);
           },
           text: 'title.privacy'.tr(),
           textStyle: labelRegular.copyWith(color: OTLColor.gray75),
@@ -250,7 +251,8 @@ class _MainPageState extends State<MainPage> {
         ),
         IconTextButton(
           onTap: () {
-            OTLNavigator.push(context, PeoplePage(), transition: 'down-up');
+            OTLNavigator.push(context, PeoplePage(),
+                transition: OTLNavigatorTransition.downUp);
           },
           text: 'title.credit'.tr(),
           textStyle: labelRegular.copyWith(color: OTLColor.gray75),

lib/utils/navigator.dart

@@ -1,97 +1,100 @@
 import 'package:flutter/material.dart';
 
+enum OTLNavigatorTransition { rightLeft, downUp, immediate }
+
+enum _TransitionHistory { rightLeft, downUp, immediate, dialog }
+
 class OTLNavigator {
   static List<Route> _rightleftTransitionHistory = [];
   static List<Route> _downupTransitionHistory = [];
-  //0 for right-left, 1 for down-up, 2 for immediate, 3 for dialog
-  static List<int> _history = [];
+  static List<_TransitionHistory> _history = [];
 
   static void _removeLastHistory() {
     switch (_history.removeLast()) {
-      case 0:
+      case _TransitionHistory.rightLeft:
         _rightleftTransitionHistory.removeLast();
         break;
-      case 1:
-      case 2:
+      case _TransitionHistory.downUp:
+      case _TransitionHistory.immediate:
         _downupTransitionHistory.removeLast();
         break;
-      case 3:
+      case _TransitionHistory.dialog:
         break;
     }
   }
 
-  static void _removeLastUntil(bool Function(int mode) predicate) {
+  static void _removeLastUntil(
+      bool Function(_TransitionHistory mode) predicate) {
     while (!predicate(_history.last)) {
       _removeLastHistory();
     }
     _removeLastHistory();
   }
 
   static Future<T?> push<T extends Object?>(BuildContext context, Widget page,
-      {String transition = "right-left"}) {
-    assert(transition == "down-up" ||
-        transition == "right-left" ||
-        transition == "immediate");
+      {OTLNavigatorTransition transition = OTLNavigatorTransition.rightLeft}) {
     Route<T> _route;
-    if (transition == "right-left") {
-      _route = buildRightLeftPageRoute<T>(page);
-      _rightleftTransitionHistory.add(_route);
-      _history.add(0);
-    } else if (transition == "down-up") {
-      _route = buildDownUpPageRoute<T>(page);
-      _downupTransitionHistory.add(_route);
-      _history.add(1);
-    } else {
-      _route = buildImmediatePageRoute<T>(page);
-      _downupTransitionHistory.add(_route);
-      _history.add(2);
+    switch (transition) {
+      case OTLNavigatorTransition.rightLeft:
+        _route = buildRightLeftPageRoute<T>(page);
+        _rightleftTransitionHistory.add(_route);
+        _history.add(_TransitionHistory.rightLeft);
+        break;
+      case OTLNavigatorTransition.downUp:
+        _route = buildDownUpPageRoute<T>(page);
+        _downupTransitionHistory.add(_route);
+        _history.add(_TransitionHistory.downUp);
+        break;
+      case OTLNavigatorTransition.immediate:
+        _route = buildImmediatePageRoute<T>(page);
+        _downupTransitionHistory.add(_route);
+        _history.add(_TransitionHistory.immediate);
+        break;
     }
     return Navigator.of(context).push(_route);
   }
 
   static Future<T?> pushRoot<T extends Object?>(
       BuildContext context, Widget page,
-      {String transition = "immediate"}) {
-    assert(transition == "down-up" ||
-        transition == "right-left" ||
-        transition == "immediate");
+      {OTLNavigatorTransition transition = OTLNavigatorTransition.immediate}) {
     _rightleftTransitionHistory.clear();
     _downupTransitionHistory.clear();
     _history.clear();
     Route<T> _route;
-    if (transition == "right-left") {
-      _route = buildRightLeftPageRoute<T>(page);
-    } else if (transition == "down-up") {
-      _route = buildDownUpPageRoute<T>(page);
-    } else {
-      _route = buildImmediatePageRoute<T>(page);
+    switch (transition) {
+      case OTLNavigatorTransition.rightLeft:
+        _route = buildRightLeftPageRoute<T>(page);
+        break;
+      case OTLNavigatorTransition.downUp:
+        _route = buildDownUpPageRoute<T>(page);
+        break;
+      case OTLNavigatorTransition.immediate:
+        _route = buildImmediatePageRoute<T>(page);
+        break;
     }
     return Navigator.of(context)
         .pushAndRemoveUntil(_route, (Route<dynamic> route) => false);
   }
 
   static void pop<T extends Object?>(BuildContext context,
-      {String transition = "none", T? result}) {
-    assert(transition == "down-up" ||
-        transition == "right-left" ||
-        transition == "immediate" ||
-        transition == "none");
+      {OTLNavigatorTransition? until, T? result}) {
     NavigatorState navigator = Navigator.of(context);
     assert(_history.isNotEmpty);
-    if (transition == "none") {
+    if (until == null) {
       _removeLastHistory();
       return navigator.pop(result);
-    } else if (transition == "right-left") {
+    } else if (until == OTLNavigatorTransition.rightLeft) {
       assert(_rightleftTransitionHistory.isNotEmpty);
       navigator.popUntil((Route<dynamic> route) =>
           _rightleftTransitionHistory.last == route || route.isFirst);
-      _removeLastUntil((mode) => mode == 0);
+      _removeLastUntil((mode) => mode == _TransitionHistory.rightLeft);
       return navigator.pop(result);
     } else {
       assert(_downupTransitionHistory.isNotEmpty);
       navigator.popUntil((Route<dynamic> route) =>
           _downupTransitionHistory.last == route || route.isFirst);
-      _removeLastUntil((mode) => (mode == 1 || mode == 2));
+      _removeLastUntil((mode) => (mode == _TransitionHistory.downUp ||
+          mode == _TransitionHistory.immediate));
       return navigator.pop(result);
     }
   }
@@ -113,7 +116,7 @@ class OTLNavigator {
     Offset? anchorPoint,
     TraversalEdgeBehavior? traversalEdgeBehavior,
   }) {
-    _history.add(3);
+    _history.add(_TransitionHistory.dialog);
     return showDialog(
       context: context,
       builder: builder,

lib/widgets/lecture_group_simple_block.dart

@@ -14,13 +14,9 @@ class LectureGroupSimpleBlock extends StatelessWidget {
   final List<Lecture> lectures;
   final int semester;
   final String? filter;
-  final bool fromLectureDetailPage;
 
   LectureGroupSimpleBlock(
-      {required this.lectures,
-      required this.semester,
-      this.filter,
-      this.fromLectureDetailPage = false});
+      {required this.lectures, required this.semester, this.filter});
 
   @override
   Widget build(BuildContext context) {
@@ -65,9 +61,8 @@ class LectureGroupSimpleBlock extends StatelessWidget {
                           context
                               .read<LectureDetailModel>()
                               .loadLecture(lecture.id, false);
-                          if (fromLectureDetailPage == false)
-                            OTLNavigator.push(context,
-                                LectureDetailPage(fromCourseDetailPage: true));
+                          OTLNavigator.push(context,
+                              LectureDetailPage(fromCourseDetailPage: true));
                         },
                         child: Padding(
                           padding: const EdgeInsets.symmetric(

lib/widgets/otl_scaffold.dart

@@ -165,7 +165,7 @@ class _OTLLayoutState extends State<OTLLayout> {
                             IconTextButton(
                                 icon: Icons.navigate_before,
                                 onTap: () => OTLNavigator.pop(context,
-                                    transition: 'right-left'),
+                                    until: OTLNavigatorTransition.rightLeft),
                                 padding: EdgeInsets.all(16)),
                           if (hasDrawer)
                             IconTextButton(
@@ -193,7 +193,7 @@ class _OTLLayoutState extends State<OTLLayout> {
                                 IconTextButton(
                                     icon: Icons.close,
                                     onTap: () => OTLNavigator.pop(context,
-                                        transition: 'down-up'),
+                                        until: OTLNavigatorTransition.downUp),
                                     padding: EdgeInsets.all(16)),
                             ],
                           )