refactor: Add snack_bar.dart

src/ui/flutter_app/lib/widgets/game_page.dart

@@ -43,6 +43,7 @@ import 'board.dart';
 import 'dialog.dart';
 import 'game_settings_page.dart';
 import 'picker.dart';
+import 'snack_bar.dart';
 
 double boardWidth = 0.0;
 
@@ -456,13 +457,13 @@ class _GamePageState extends State<GamePage>
     if (isMoveNow == true) {
       if (!Game.instance.isAiToMove()) {
         print("[engineToGo] Human to Move. Cannot get search result now.");
-        showSnackBar(S.of(context).notAIsTurn);
+        showSnackBar(context, S.of(context).notAIsTurn);
         return;
       }
       if (!Game.instance.position.recorder.isClean()) {
         print(
             "[engineToGo] History is not clean. Cannot get search result now.");
-        showSnackBar(S.of(context).aiIsNotThinking);
+        showSnackBar(context, S.of(context).aiIsNotThinking);
         return;
       }
     }
@@ -593,7 +594,7 @@ class _GamePageState extends State<GamePage>
     final moveHistoryText = Game.instance.position.moveHistoryText;
 
     Clipboard.setData(ClipboardData(text: moveHistoryText)).then((_) {
-      showSnackBar(S.of(context).moveHistoryCopied);
+      showSnackBar(context, S.of(context).moveHistoryCopied);
     });
   }
 
@@ -893,10 +894,10 @@ class _GamePageState extends State<GamePage>
       case "null":
       case "out-of-range":
       case "equal":
-        showSnackBar(S.of(context).atEnd);
+        showSnackBar(context, S.of(context).atEnd);
         break;
       default:
-        showSnackBar(S.of(context).movesAndRulesNotMatch);
+        showSnackBar(context, S.of(context).movesAndRulesNotMatch);
         break;
     }
 
@@ -981,7 +982,7 @@ class _GamePageState extends State<GamePage>
               onPressed: () =>
                   Clipboard.setData(ClipboardData(text: moveHistoryText))
                       .then((_) {
-                showSnackBar(S.of(context).moveHistoryCopied);
+                showSnackBar(context, S.of(context).moveHistoryCopied);
               }),
             ),
             TextButton(
@@ -1369,20 +1370,6 @@ class _GamePageState extends State<GamePage>
     );
   }
 
-  void showSnackBar(String message,
-      {Duration duration = const Duration(milliseconds: 4000)}) {
-    ScaffoldMessenger.of(context).hideCurrentSnackBar();
-    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
-      content: Text(
-        message,
-        style: TextStyle(
-          fontSize: Config.fontSize,
-        ),
-      ),
-      duration: duration,
-    ));
-  }
-
   String getInfoText() {
     String ret = S.of(context).score +
         "\n" +

src/ui/flutter_app/lib/widgets/snack_bar.dart

@@ -0,0 +1,34 @@
+/*
+  This file is part of Sanmill.
+  Copyright (C) 2019-2021 The Sanmill developers (see AUTHORS file)
+
+  Sanmill is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  Sanmill is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import 'package:flutter/material.dart';
+import 'package:sanmill/common/config.dart';
+
+void showSnackBar(BuildContext context, String message,
+    {Duration duration = const Duration(milliseconds: 4000)}) {
+  ScaffoldMessenger.of(context).hideCurrentSnackBar();
+  ScaffoldMessenger.of(context).showSnackBar(SnackBar(
+    content: Text(
+      message,
+      style: TextStyle(
+        fontSize: Config.fontSize,
+      ),
+    ),
+    duration: duration,
+  ));
+}