Improve Cupertino bottom bar style

lib/src/view/analysis/analysis_screen.dart

@@ -232,7 +232,8 @@ class _BottomBar extends ConsumerWidget {
     final ctrlProvider = analysisControllerProvider(options);
     final analysisState = ref.watch(ctrlProvider).requireValue;
 
-    return BottomBar(
+    return PlatformBottomBar(
+      transparentCupertinoBar: false,
       children: [
         BottomBarButton(
           label: context.l10n.menu,

lib/src/view/board_editor/board_editor_screen.dart

@@ -280,7 +280,7 @@ class _BottomBar extends ConsumerWidget {
     final editorState = ref.watch(boardEditorControllerProvider(initialFen));
     final pieceCount = editorState.pieces.length;
 
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         BottomBarButton(
           label: context.l10n.menu,

lib/src/view/broadcast/broadcast_game_bottom_bar.dart

@@ -32,7 +32,8 @@ class BroadcastGameBottomBar extends ConsumerWidget {
     final ctrlProvider = broadcastAnalysisControllerProvider(roundId, gameId);
     final broadcastAnalysisState = ref.watch(ctrlProvider).requireValue;
 
-    return BottomBar(
+    return PlatformBottomBar(
+      transparentCupertinoBar: false,
       children: [
         BottomBarButton(
           label: context.l10n.menu,

lib/src/view/broadcast/broadcast_round_screen.dart

@@ -138,7 +138,7 @@ class _BroadcastRoundScreenState extends ConsumerState<BroadcastRoundScreen>
               setTournamentId: setTournamentId,
               setRoundId: setRoundId,
             ),
-            _ => const BottomBar.empty(),
+            _ => const PlatformBottomBar.empty(transparentCupertinoBar: false),
           },
         ],
       ),
@@ -199,7 +199,7 @@ class _BroadcastRoundScreenState extends ConsumerState<BroadcastRoundScreen>
           setTournamentId: setTournamentId,
           setRoundId: setRoundId,
         ),
-        _ => const BottomBar.empty(),
+        _ => const PlatformBottomBar.empty(transparentCupertinoBar: false),
       },
     );
   }
@@ -284,7 +284,8 @@ class _BottomBar extends ConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    return BottomBar(
+    return PlatformBottomBar(
+      transparentCupertinoBar: false,
       children: [
         if (tournament.group != null)
           AdaptiveTextButton(

lib/src/view/coordinate_training/coordinate_training_screen.dart

@@ -178,7 +178,7 @@ class _BodyState extends ConsumerState<_Body> {
             ),
           ),
           if (!trainingState.trainingActive)
-            BottomBar(
+            PlatformBottomBar(
               children: [
                 BottomBarButton(
                   label: context.l10n.menu,

lib/src/view/correspondence/offline_correspondence_game_screen.dart

@@ -210,7 +210,7 @@ class _BodyState extends ConsumerState<_Body> {
             ),
           ),
         ),
-        BottomBar(
+        PlatformBottomBar(
           children: [
             BottomBarButton(
               label: context.l10n.flipBoard,

lib/src/view/game/archived_game_screen.dart

@@ -251,7 +251,7 @@ class _BottomBar extends ConsumerWidget {
     final gameData = archivedGameData;
 
     if (gameData == null) {
-      return const BottomBar(children: []);
+      return const PlatformBottomBar(children: []);
     }
 
     final canGoForward = ref.watch(canGoForwardProvider(gameData.id));
@@ -283,7 +283,7 @@ class _BottomBar extends ConsumerWidget {
       );
     }
 
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         BottomBarButton(label: context.l10n.menu, onTap: showGameMenu, icon: Icons.menu),
         if (gameCursor.hasValue)

lib/src/view/game/game_body.dart

@@ -413,7 +413,7 @@ class _GameBottomBar extends ConsumerWidget {
     final chatStateAsync =
         gamePrefs.enableChat == true ? ref.watch(chatControllerProvider(id)) : null;
 
-    return BottomBar(
+    return PlatformBottomBar(
       children: gameStateAsync.when(
         data: (gameState) {
           final isChatEnabled = chatStateAsync != null && !gameState.isZenModeActive;

lib/src/view/game/game_loading_board.dart

@@ -72,7 +72,7 @@ class LobbyScreenLoadingContent extends StatelessWidget {
             ),
           ),
         ),
-        BottomBar(
+        PlatformBottomBar(
           children: [
             BottomBarButton(
               onTap: () async {
@@ -148,7 +148,7 @@ class ChallengeLoadingContent extends StatelessWidget {
             ),
           ),
         ),
-        BottomBar(
+        PlatformBottomBar(
           children: [
             BottomBarButton(
               onTap: () async {
@@ -258,7 +258,7 @@ class LoadGameError extends StatelessWidget {
             ),
           ),
         ),
-        BottomBar(
+        PlatformBottomBar(
           children: [
             BottomBarButton(
               onTap: () => Navigator.of(context).pop(),
@@ -339,7 +339,7 @@ class ChallengeDeclinedBoard extends StatelessWidget {
             ),
           ),
         ),
-        BottomBar(
+        PlatformBottomBar(
           children: [
             BottomBarButton(
               onTap: () => Navigator.of(context).pop(),

lib/src/view/opening_explorer/opening_explorer_screen.dart

@@ -252,7 +252,8 @@ class _BottomBar extends ConsumerWidget {
       OpeningDatabase.player => context.l10n.player,
     };
 
-    return BottomBar(
+    return PlatformBottomBar(
+      transparentCupertinoBar: false,
       children: [
         BottomBarButton(
           label: dbLabel,

lib/src/view/over_the_board/over_the_board_screen.dart

@@ -187,7 +187,7 @@ class _BottomBar extends ConsumerWidget {
 
     final clock = ref.watch(overTheBoardClockProvider);
 
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         BottomBarButton(
           label: 'Configure game',

lib/src/view/puzzle/puzzle_screen.dart

@@ -185,7 +185,7 @@ class _LoadPuzzleFromId extends ConsumerWidget {
                   child: BoardTable.empty(showEngineGaugePlaceholder: true),
                 ),
               ),
-              BottomBar.empty(),
+              PlatformBottomBar.empty(),
             ],
           ),
       error: (e, s) {
@@ -346,7 +346,7 @@ class _BottomBar extends ConsumerWidget {
     final puzzleState = ref.watch(ctrlProvider);
     final isDailyPuzzle = puzzleState.puzzle.isDailyPuzzle == true;
 
-    return BottomBar(
+    return PlatformBottomBar(
       mainAxisAlignment: MainAxisAlignment.spaceAround,
       children: [
         if (initialPuzzleContext.userId != null &&

lib/src/view/puzzle/storm_screen.dart

@@ -528,7 +528,7 @@ class _BottomBar extends ConsumerWidget {
   @override
   Widget build(BuildContext context, WidgetRef ref) {
     final stormState = ref.watch(ctrl);
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         if (stormState.mode == StormMode.initial)
           BottomBarButton(

lib/src/view/puzzle/streak_screen.dart

@@ -215,7 +215,7 @@ class _BottomBar extends ConsumerWidget {
     final ctrlProvider = puzzleControllerProvider(initialPuzzleContext, initialStreak: streak);
     final puzzleState = ref.watch(ctrlProvider);
 
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         if (!puzzleState.streak!.finished)
           BottomBarButton(

lib/src/view/study/study_bottom_bar.dart

@@ -37,15 +37,16 @@ class _AnalysisBottomBar extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final state = ref.watch(studyControllerProvider(id)).valueOrNull;
     if (state == null) {
-      return const BottomBar(children: []);
+      return const PlatformBottomBar(children: []);
     }
 
     final onGoForward =
         state.canGoNext ? ref.read(studyControllerProvider(id).notifier).userNext : null;
     final onGoBack =
         state.canGoBack ? ref.read(studyControllerProvider(id).notifier).userPrevious : null;
 
-    return BottomBar(
+    return PlatformBottomBar(
+      transparentCupertinoBar: false,
       children: [
         _ChapterButton(state: state),
         _NextChapterButton(
@@ -90,7 +91,7 @@ class _GamebookBottomBar extends ConsumerWidget {
   Widget build(BuildContext context, WidgetRef ref) {
     final state = ref.watch(studyControllerProvider(id)).requireValue;
 
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         _ChapterButton(state: state),
         ...switch (state.gamebookState) {

lib/src/view/watch/tv_screen.dart

@@ -182,7 +182,7 @@ class _BottomBar extends ConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
-    return BottomBar(
+    return PlatformBottomBar(
       children: [
         BottomBarButton(
           label: context.l10n.flipBoard,

lib/src/widgets/bottom_bar.dart

@@ -4,15 +4,18 @@ import 'package:lichess_mobile/src/constants.dart';
 
 /// A container in the style of a bottom app bar, containg a [Row] of children widgets.
 ///
+/// It adapts to the current platform, using a [BottomAppBar] on Android and a [ColoredBox] on iOS.
+///
 /// The height of the bar is always [kBottomBarHeight].
-class BottomBar extends StatelessWidget {
-  const BottomBar({
+class PlatformBottomBar extends StatelessWidget {
+  const PlatformBottomBar({
     required this.children,
     this.mainAxisAlignment = MainAxisAlignment.spaceAround,
     this.expandChildren = true,
+    this.transparentCupertinoBar = true,
   });
 
-  const BottomBar.empty()
+  const PlatformBottomBar.empty({this.transparentCupertinoBar = true})
     : children = const [],
       expandChildren = true,
       mainAxisAlignment = MainAxisAlignment.spaceAround;
@@ -26,15 +29,20 @@ class BottomBar extends StatelessWidget {
   /// Whether to expand the children to fill the available space. Defaults to true.
   final bool expandChildren;
 
+  /// Whether to make the Cupertino bar transparent. Defaults to true.
+  final bool transparentCupertinoBar;
+
   @override
   Widget build(BuildContext context) {
     if (Theme.of(context).platform == TargetPlatform.iOS) {
       return ColoredBox(
-        color: CupertinoTheme.of(context).barBackgroundColor,
-        child: SafeArea(
-          top: false,
-          child: SizedBox(
-            height: kBottomBarHeight,
+        color: CupertinoTheme.of(
+          context,
+        ).barBackgroundColor.withValues(alpha: transparentCupertinoBar ? 0.0 : null),
+        child: SizedBox(
+          height: kBottomBarHeight + MediaQuery.paddingOf(context).bottom,
+          child: SafeArea(
+            top: false,
             child: Row(
               crossAxisAlignment: CrossAxisAlignment.center,
               mainAxisAlignment: mainAxisAlignment,

lib/src/widgets/bottom_bar_button.dart

@@ -1,7 +1,10 @@
 import 'package:flutter/material.dart';
+import 'package:lichess_mobile/src/widgets/bottom_bar.dart';
 import 'package:lichess_mobile/src/widgets/buttons.dart';
 
 /// A bottom bar button.
+///
+/// Typically used in a [PlatformBottomBar].
 class BottomBarButton extends StatelessWidget {
   const BottomBarButton({
     required this.icon,