Refactorings suggestions

lib/dash_sweeper.dart

@@ -29,16 +29,10 @@ class _DashSweeperState extends State<DashSweeper> {
     final dashAmount = amount ~/ 10; // TODO customize percentage
     final emptyAmount = amount - dashAmount;
 
-    // create tiles
-    final dashTiles = List.generate(
-      dashAmount,
-      (_) => DashTile(TileState.idle),
-    );
-    final emptyTiles = List.generate(
-      emptyAmount,
-      (_) => EmptyTile(TileState.idle),
-    );
-    tiles = [...dashTiles, ...emptyTiles]..shuffle();
+    tiles = [
+      for (var _ in dashAmount.thisLengthList) DashTile(TileState.idle),
+      for (var _ in emptyAmount.thisLengthList) EmptyTile(TileState.idle),
+    ]..shuffle();
   }
 
   bool inBounds(int row, int column) {
@@ -48,79 +42,27 @@ class _DashSweeperState extends State<DashSweeper> {
         column < widget.columns;
   }
 
-  int? getIndex(int row, int column) {
+  int? getIndex(NamedPoint point) {
+    var (:row, :column) = point;
     if (!inBounds(row, column)) return null;
     return (row * widget.columns) + column;
   }
 
-  (int row, int column) getPointForIndex(int index) {
+  NamedPoint getPointForIndex(int index) {
     final row = (index / widget.columns).floor();
     final column = index % widget.columns;
-    return (row, column);
-  }
-
-  int? topLeftIndex(int row, int column) {
-    final targetRow = row - 1;
-    final targetColumn = column - 1;
-    return getIndex(targetRow, targetColumn);
-  }
-
-  int? topCenterIndex(int row, int column) {
-    final targetRow = row - 1;
-    return getIndex(targetRow, column);
-  }
-
-  int? topRightIndex(int row, int column) {
-    final targetRow = row - 1;
-    final targetColumn = column + 1;
-    return getIndex(targetRow, targetColumn);
+    return (row: row, column: column);
   }
 
-  int? leftIndex(int row, int column) {
-    final targetColumn = column - 1;
-    return getIndex(row, targetColumn);
-  }
-
-  int? rightIndex(int row, int column) {
-    final targetColumn = column + 1;
-    return getIndex(row, targetColumn);
-  }
-
-  int? bottomLeftIndex(int row, int column) {
-    final targetRow = row + 1;
-    final targetColumn = column - 1;
-    return getIndex(targetRow, targetColumn);
-  }
-
-  int? bottomCenterIndex(int row, int column) {
-    final targetRow = row + 1;
-    return getIndex(targetRow, column);
-  }
-
-  int? bottomRightIndex(int row, int column) {
-    final targetRow = row + 1;
-    final targetColumn = column + 1;
-    return getIndex(targetRow, targetColumn);
-  }
-
-  List<int> getNeighbouringDashes(int index) {
-    return getNeighbouringIndeces(
-      index,
-    ).where((tileIndex) => tiles[tileIndex] is DashTile).toList();
+  int countNeighbouringDashes(int index) {
+    return getNeighbouringIndeces(index) // formatting hack
+        .where((tileIndex) => tiles[tileIndex] is DashTile)
+        .length;
   }
 
   Iterable<int> getNeighbouringIndeces(int index) {
-    final (row, column) = getPointForIndex(index);
-    return [
-      topLeftIndex(row, column),
-      topCenterIndex(row, column),
-      topRightIndex(row, column),
-      leftIndex(row, column),
-      rightIndex(row, column),
-      bottomLeftIndex(row, column),
-      bottomCenterIndex(row, column),
-      bottomRightIndex(row, column),
-    ].nonNulls;
+    final point = getPointForIndex(index);
+    return point.adjacents.map(getIndex).nonNulls;
   }
 
   void handleOnLongPress(int index) {
@@ -139,7 +81,7 @@ class _DashSweeperState extends State<DashSweeper> {
 
   void handleOnTap(int index) {
     final tile = tiles[index];
-    if (tile.state != TileState.idle) return;
+    if (!tile.state.isIdle) return;
 
     if (tile is DashTile) {
       _gameOver();
@@ -236,8 +178,8 @@ class _DashSweeperState extends State<DashSweeper> {
     toReveal.add(index);
     checked.add(index);
 
-    final dashes = getNeighbouringDashes(index);
-    if (dashes.isNotEmpty) return toReveal;
+    final dashes = countNeighbouringDashes(index);
+    if (dashes > 0) return toReveal;
 
     final neighbours = getNeighbouringIndeces(index);
     if (checked.containsAll(neighbours)) return toReveal;
@@ -265,7 +207,7 @@ class _DashSweeperState extends State<DashSweeper> {
               onLongPress: () => handleOnLongPress(index),
             ),
             EmptyTile(:final state) => EmptyTileItem(
-              amount: getNeighbouringDashes(index).length,
+              amount: countNeighbouringDashes(index),
               state: state,
               onTap: () => handleOnTap(index),
               onLongPress: () => handleOnLongPress(index),
@@ -277,7 +219,15 @@ class _DashSweeperState extends State<DashSweeper> {
   }
 }
 
-enum TileState { idle, revealed, flagged }
+enum TileState {
+  idle,
+  revealed,
+  flagged;
+
+  bool get isIdle => this == TileState.idle;
+  bool get isRevealed => this == TileState.revealed;
+  bool get isFlagged => this == TileState.flagged;
+}
 
 sealed class Tile {
   final TileState state;
@@ -375,18 +325,18 @@ class TileItem extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Card(
-      elevation: state != TileState.idle ? 0 : 4,
+      elevation: state.isIdle ? 4 : 0,
       clipBehavior: Clip.antiAliasWithSaveLayer,
       child: InkWell(
-        onTap: onTap,
-        onLongPress: onLongPress,
+        onTap: state.isIdle ? onTap : null,
+        onLongPress: state.isIdle ? onLongPress : null,
         child: Center(
           child: AnimatedSwitcher(
             duration: Duration(milliseconds: 300),
             child: switch (state) {
-              TileState.idle => SizedBox(),
+              TileState.idle => const SizedBox.shrink(),
               TileState.revealed => child,
-              TileState.flagged => Icon(
+              TileState.flagged => const Icon(
                 Icons.flag,
                 color: Colors.red,
               ),
@@ -397,3 +347,20 @@ class TileItem extends StatelessWidget {
     );
   }
 }
+
+typedef NamedPoint = ({int row, int column});
+
+extension on int {
+  List<int> get adjacents => [this - 1, this, this + 1];
+
+  List<int> get thisLengthList => [for (var i = 0; i < this; i++) i];
+}
+
+extension on NamedPoint {
+  List<NamedPoint> get adjacents {
+    return [
+      for (var row in row.adjacents)
+        for (var column in column.adjacents) (row: row, column: column),
+    ];
+  }
+}