Implement moves by tapping the squares

This adds an option to dragging-and-dropping which is slightly hard on
smaller screens.

lib/chess/chess_app.dart

@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:mchess/chess_bloc/chess_bloc.dart';
 import 'package:mchess/chess_bloc/promotion_bloc.dart';
+import 'package:mchess/chess_bloc/tap_bloc.dart';
 import 'package:mchess/connection_cubit/connection_cubit.dart';
 import 'package:mchess/utils/chess_router.dart';
 
@@ -20,7 +21,8 @@ class ChessApp extends StatelessWidget {
         ),
         BlocProvider(
           create: (context) => PromotionBloc.getInstance(),
-        )
+        ),
+        BlocProvider(create: (context) => TapBloc.getInstance()),
       ],
       child: MaterialApp.router(
         theme: ThemeData.dark(

lib/chess/chess_board.dart

@@ -13,7 +13,8 @@ class ChessBoard extends StatelessWidget {
 
   const ChessBoard._({required this.bState, required this.squares});
 
-  factory ChessBoard({required ChessBoardState boardState}) {
+  factory ChessBoard(
+      {required ChessBoardState boardState, ChessCoordinate? tappedSquare}) {
     List<ChessSquare> squares = List.empty(growable: true);
     for (int i = 0; i < 64; i++) {
       var column = (i % 8) + 1;
@@ -30,10 +31,10 @@ class ChessBoard extends StatelessWidget {
 
       squares.add(
         ChessSquare(
-          ChessCoordinate(column, row),
-          piece,
-          squareWasPartOfLastMove,
-        ),
+            ChessCoordinate(column, row),
+            piece,
+            squareWasPartOfLastMove,
+            tappedSquare == ChessCoordinate(column, row)),
       );
     }
 

lib/chess/chess_square.dart

@@ -1,7 +1,6 @@
 import 'package:flutter/material.dart';
-import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:mchess/chess/chess_square_outer_dragtarget.dart';
-import 'package:mchess/chess_bloc/chess_bloc.dart';
+import 'package:mchess/chess_bloc/tap_bloc.dart';
 import '../utils/chess_utils.dart';
 
 class ChessSquare extends StatefulWidget {
@@ -18,13 +17,18 @@ class ChessSquare extends StatefulWidget {
     required this.color,
   });
 
-  factory ChessSquare(
-      ChessCoordinate coord, ChessPiece? piece, bool wasPartOfLastMove) {
+  factory ChessSquare(ChessCoordinate coord, ChessPiece? piece,
+      bool wasPartOfLastMove, bool wasTapped) {
     Color lightSquaresColor =
         wasPartOfLastMove ? Colors.green.shade200 : Colors.brown.shade50;
     Color darkSquaresColor =
         wasPartOfLastMove ? Colors.green.shade300 : Colors.brown.shade400;
 
+    if (wasTapped) {
+      lightSquaresColor = Colors.red.shade200;
+      darkSquaresColor = Colors.red.shade300;
+    }
+
     Color squareColor;
 
     if (coord.row % 2 == 0) {
@@ -53,31 +57,19 @@ class ChessSquare extends StatefulWidget {
 }
 
 class _ChessSquareState extends State<ChessSquare> {
-  late Color squareColor;
-
-  @override
-  void initState() {
-    squareColor = widget.color;
-    super.initState();
-  }
-
   @override
   Widget build(BuildContext context) {
-    return BlocListener<ChessBloc, ChessBoardState>(
-      listenWhen: (previous, current) {
-        return true;
-      },
-      listener: (context, state) {
-        setState(() {
-          squareColor = Colors.red;
-        });
-      },
+    return GestureDetector(
       child: Container(
         color: widget.color,
         child: ChessSquareOuterDragTarget(
             coordinate: widget.coordinate,
             containedPiece: widget.containedPiece ?? const ChessPiece.none()),
       ),
+      onTap: () {
+        TapBloc().add(SquareTappedEvent(
+            tapped: widget.coordinate, pieceOnSquare: widget.containedPiece));
+      },
     );
   }
 }

lib/chess/chess_square_outer_dragtarget.dart

@@ -25,7 +25,11 @@ class ChessSquareOuterDragTarget extends StatelessWidget {
         // Replace the dummy value with the actual target of the move.
         pieceDragged.toSquare = coordinate;
 
-        if (isPromotionMove(pieceDragged)) {
+        if (isPromotionMove(
+          pieceDragged.movedPiece!.pieceClass,
+          ChessBloc.myColor!,
+          pieceDragged.toSquare,
+        )) {
           var move = ChessMove(
               from: pieceDragged.fromSquare, to: pieceDragged.toSquare);
           PromotionBloc.getInstance().add(PawnMovedToPromotionField(
@@ -33,8 +37,7 @@ class ChessSquareOuterDragTarget extends StatelessWidget {
         } else if (coordinate != pieceDragged.fromSquare) {
           ChessBloc.getInstance().add(OwnPieceMoved(
               startSquare: pieceDragged.fromSquare,
-              endSquare: pieceDragged.toSquare,
-              piece: pieceDragged.movedPiece!));
+              endSquare: pieceDragged.toSquare));
         }
       },
       builder: (context, candidateData, rejectedData) {
@@ -45,28 +48,4 @@ class ChessSquareOuterDragTarget extends StatelessWidget {
       },
     );
   }
-
-  bool isPromotionMove(PieceDragged move) {
-    bool isPromotion = false;
-    if (move.movedPiece!.pieceClass != ChessPieceClass.pawn) {
-      return isPromotion;
-    }
-
-    switch (ChessBloc.myColor) {
-      case ChessColor.black:
-        if (move.toSquare.row == 1) {
-          isPromotion = true;
-        }
-        break;
-      case ChessColor.white:
-        if (move.toSquare.row == 8) {
-          isPromotion = true;
-        }
-        break;
-      case null:
-        break;
-    }
-
-    return isPromotion;
-  }
 }

lib/chess_bloc/chess_events.dart

@@ -22,12 +22,8 @@ class ReceivedBoardState extends ChessEvent {
 class OwnPieceMoved extends ChessEvent {
   final ChessCoordinate startSquare;
   final ChessCoordinate endSquare;
-  final ChessPiece piece;
 
-  OwnPieceMoved(
-      {required this.startSquare,
-      required this.endSquare,
-      required this.piece});
+  OwnPieceMoved({required this.startSquare, required this.endSquare});
 }
 
 class OwnPromotionPlayed extends ChessEvent {

lib/chess_bloc/tap_bloc.dart

@@ -0,0 +1,92 @@
+import 'dart:developer';
+
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:mchess/chess_bloc/chess_bloc.dart';
+import 'package:mchess/chess_bloc/chess_events.dart';
+import 'package:mchess/utils/chess_utils.dart';
+
+class TapBloc extends Bloc<TapEvent, TapState> {
+  static final TapBloc _instance = TapBloc._internal();
+
+  static TapBloc getInstance() {
+    return _instance;
+  }
+
+  factory TapBloc() {
+    return _instance;
+  }
+
+  TapBloc._internal() : super(TapState.init()) {
+    on<SquareTappedEvent>(handleTap);
+  }
+
+  void handleTap(SquareTappedEvent event, Emitter<TapState> emit) {
+    ChessCoordinate? firstTappedSquare, secondTappedSquare;
+    ChessPiece? piece;
+
+    if (ChessBloc.myColor != ChessBloc.turnColor) return;
+
+    if (state.firstSquareTapped == null) {
+      //first tap
+      if (event.pieceOnSquare == null) return;
+      firstTappedSquare = event.tapped;
+      piece = event.pieceOnSquare;
+    } else {
+      //second tap
+      secondTappedSquare = event.tapped;
+    }
+
+    if (state.firstSquareTapped != null &&
+        state.firstSquareTapped != event.tapped) {
+      if (isPromotionMove(
+        state.pieceOnFirstTappedSquare!.pieceClass,
+        ChessBloc.myColor!,
+        event.tapped,
+      )) {
+        ChessBloc().add(OwnPromotionPlayed(
+            pieceClass: state.pieceOnFirstTappedSquare!.pieceClass,
+            move: ChessMove(from: state.firstSquareTapped!, to: event.tapped)));
+        emit(TapState.init());
+        return;
+      } else {
+        ChessBloc().add(OwnPieceMoved(
+            startSquare: state.firstSquareTapped!, endSquare: event.tapped));
+        emit(TapState.init());
+        return;
+      }
+    }
+    log("handleTap() in TapBloc is called");
+    emit(TapState(
+        firstSquareTapped: firstTappedSquare,
+        pieceOnFirstTappedSquare: piece,
+        secondSquareTapped: secondTappedSquare));
+  }
+}
+
+abstract class TapEvent {}
+
+class SquareTappedEvent extends TapEvent {
+  ChessCoordinate tapped;
+  ChessPiece? pieceOnSquare;
+
+  SquareTappedEvent({required this.tapped, required this.pieceOnSquare});
+}
+
+class TapState {
+  ChessCoordinate? firstSquareTapped;
+  ChessPiece? pieceOnFirstTappedSquare;
+
+  ChessCoordinate? secondSquareTapped;
+
+  TapState(
+      {required this.firstSquareTapped,
+      required this.pieceOnFirstTappedSquare,
+      required this.secondSquareTapped});
+
+  factory TapState.init() {
+    return TapState(
+        firstSquareTapped: null,
+        pieceOnFirstTappedSquare: null,
+        secondSquareTapped: null);
+  }
+}

lib/connection/ws_connection.dart

@@ -1,6 +1,5 @@
 import 'dart:convert';
 import 'dart:developer';
-import 'package:flutter/foundation.dart';
 import 'package:mchess/api/move.dart';
 import 'package:mchess/api/websocket_message.dart';
 import 'package:mchess/chess_bloc/chess_bloc.dart';
@@ -40,11 +39,7 @@ class ServerConnection {
 
   void connect(String playerID, lobbyID, String? passphrase) {
     String url;
-    if (kDebugMode) {
-      url = 'ws://localhost:8080/api/ws';
-    } else {
-      url = 'wss://chess.sw-gross.de:9999/api/ws';
-    }
+    url = 'wss://chess.sw-gross.de:9999/api/ws';
     channel = WebSocketChannel.connect(Uri.parse(url));
 
     send(

lib/pages/chess_game.dart

@@ -5,6 +5,7 @@ import 'package:mchess/chess_bloc/chess_bloc.dart';
 
 import 'package:mchess/chess/chess_board.dart';
 import 'package:mchess/chess_bloc/promotion_bloc.dart';
+import 'package:mchess/chess_bloc/tap_bloc.dart';
 import 'package:mchess/utils/chess_utils.dart';
 import 'package:mchess/utils/widgets/promotion_dialog.dart';
 import 'package:universal_platform/universal_platform.dart';
@@ -25,10 +26,7 @@ class ChessGame extends StatefulWidget {
 }
 
 class _ChessGameState extends State<ChessGame> {
-  @override
-  void initState() {
-    super.initState();
-  }
+  ChessCoordinate? tappedSquare;
 
   @override
   Widget build(BuildContext context) {
@@ -48,18 +46,26 @@ class _ChessGameState extends State<ChessGame> {
       body: Center(
         child: Container(
           margin: const EdgeInsets.all(10),
-          child: BlocListener<PromotionBloc, PromotionState>(
-            listener: (listenerContext, state) {
-              if (state.showPromotionDialog) {
-                promotionDialogBuilder(listenerContext, state.colorMoved);
-              }
+          child: BlocListener<TapBloc, TapState>(
+            listener: (context, state) {
+              setState(() {
+                tappedSquare = state.firstSquareTapped;
+              });
             },
-            child: BlocBuilder<ChessBloc, ChessBoardState>(
-              builder: (context, state) {
-                return ChessBoard(
-                  boardState: state,
-                );
+            child: BlocListener<PromotionBloc, PromotionState>(
+              listener: (listenerContext, state) {
+                if (state.showPromotionDialog) {
+                  promotionDialogBuilder(listenerContext, state.colorMoved);
+                }
               },
+              child: BlocBuilder<ChessBloc, ChessBoardState>(
+                builder: (context, state) {
+                  return ChessBoard(
+                    boardState: state,
+                    tappedSquare: tappedSquare,
+                  );
+                },
+              ),
             ),
           ),
         ),

lib/pages/host_game.dart

@@ -1,6 +1,5 @@
 import 'dart:developer';
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:go_router/go_router.dart';
@@ -101,11 +100,7 @@ class _HostGameWidgetState extends State<HostGameWidget> {
     String addr;
     Response response;
 
-    if (kDebugMode) {
-      addr = 'http://localhost:8080/api/hostPrivate';
-    } else {
-      addr = 'https://chess.sw-gross.de:9999/api/hostPrivate';
-    }
+    addr = 'https://chess.sw-gross.de:9999/api/hostPrivate';
 
     try {
       response = await http

lib/pages/lobby_selector.dart

@@ -1,7 +1,6 @@
 import 'dart:convert';
 import 'dart:developer';
 
-import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:http/http.dart' as http;
@@ -157,11 +156,7 @@ class _LobbySelectorState extends State<LobbySelector> {
     var info = PlayerInfo(
         playerID: null, lobbyID: null, passphrase: phraseController.text);
 
-    if (kDebugMode) {
-      addr = 'http://localhost:8080/api/joinPrivate';
-    } else {
-      addr = 'https://chess.sw-gross.de:9999/api/joinPrivate';
-    }
+    addr = 'https://chess.sw-gross.de:9999/api/joinPrivate';
 
     try {
       response = await http.post(Uri.parse(addr),

lib/utils/chess_utils.dart

@@ -363,3 +363,26 @@ class PieceDragged {
 
   PieceDragged(this.fromSquare, this.toSquare, this.movedPiece);
 }
+
+bool isPromotionMove(
+    ChessPieceClass pieceMoved, ChessColor myColor, ChessCoordinate toSquare) {
+  bool isPromotion = false;
+  if (pieceMoved != ChessPieceClass.pawn) {
+    return isPromotion;
+  }
+
+  switch (myColor) {
+    case ChessColor.black:
+      if (toSquare.row == 1) {
+        isPromotion = true;
+      }
+      break;
+    case ChessColor.white:
+      if (toSquare.row == 8) {
+        isPromotion = true;
+      }
+      break;
+  }
+
+  return isPromotion;
+}