add play, stop, reset controls for sorting

Author: AhmedAbdoElhawary

lib/features/sorting/view_model/sorting_notifier.dart

@@ -1,10 +1,14 @@
 import 'package:algorithm_visualizer/core/helpers/screen_size.dart';
+import 'package:collection/collection.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_screenutil/flutter_screenutil.dart';
+import 'package:async/async.dart';
 
 part 'sorting_state.dart';
 
+enum SortingEnum { played, stopped, none }
+
 class SortableItem {
   final int id;
   final int value;
@@ -13,17 +17,20 @@ class SortableItem {
 }
 
 class SortingNotifier extends StateNotifier<SortingNotifierState> {
-  SortingNotifier()
-      : super(SortingNotifierState(
-          list: List.generate(_listSize, (index) => SortableItem(index, index + 1))..shuffle(),
-        )) {
+  SortingNotifier() : super(SortingNotifierState(list: generateList())) {
     _initializePositions();
   }
 
   static const int _listSize = 50;
   static double maxListItemHeight = 250.h;
   static double itemsPadding = 1.w;
   static const Duration swipeDuration = Duration(milliseconds: 5);
+  SortingEnum _operation = SortingEnum.none;
+  CancelableOperation<void>? _cancelableBubbleSort;
+
+  static List<SortableItem> generateList() {
+    return List.generate(_listSize, (index) => SortableItem(index, index + 1))..shuffle();
+  }
 
   static double calculateItemWidth(BuildContext context) {
     final screenWidth = MediaQuery.of(context).size.width;
@@ -40,7 +47,9 @@ class SortingNotifier extends StateNotifier<SortingNotifierState> {
 
   static Color getColor(int itemIndex) {
     double step = (itemIndex * 2) / 100;
-    return Colors.indigo.withOpacity(step);
+    final value = step + 0.1 > 1 ? 1.0 : step + 0.1;
+
+    return Colors.indigo.withOpacity(value);
   }
 
   void _initializePositions() {
@@ -53,27 +62,62 @@ class SortingNotifier extends StateNotifier<SortingNotifierState> {
     state = state.copyWith(positions: positions);
   }
 
+  void stopSorting() {
+    _cancelableBubbleSort?.cancel();
+    _operation = SortingEnum.stopped;
+  }
+
+  void playSorting() {
+    if (_operation == SortingEnum.played) return;
+    _operation = SortingEnum.played;
+
+    bubbleSort();
+  }
+
+  void generateAgain() {
+    _operation = SortingEnum.stopped;
+
+    i = 0;
+    j = 0;
+
+    state = state.copyWith(list: generateList());
+    _initializePositions();
+  }
+
+  int i = 0;
+  int j = 0;
+
   Future<void> bubbleSort() async {
+    _cancelableBubbleSort = CancelableOperation.fromFuture(_bubbleSort());
+    try {
+      await _cancelableBubbleSort?.value;
+    } catch (e) {
+      debugPrint("something wrong with bubbleSort: $e");
+    }
+  }
+
+  Future<void> _bubbleSort() async {
     final list = List<SortableItem>.from(state.list);
-    for (int i = 0; i < list.length - 1; i++) {
-      for (int j = 0; j < list.length - i - 1; j++) {
+
+    for (i = 0; i < list.length - 1; i++) {
+      if (_operation != SortingEnum.played) return;
+
+      for (j = 0; j < list.length - i - 1; j++) {
+        if (_operation != SortingEnum.played) return;
+
         if (list[j].value > list[j + 1].value) {
-          // Swap items in the list
-          final temp = list[j];
-          list[j] = list[j + 1];
-          list[j + 1] = temp;
+          if (_operation != SortingEnum.played) return;
+          list.swap(j, j + 1);
 
-          // Update positions for swap
           final positions = Map<int, Offset>.from(state.positions);
           final tempPosition = positions[list[j].id]!;
           positions[list[j].id] = positions[list[j + 1].id]!;
           positions[list[j + 1].id] = tempPosition;
 
-          // Update state
           state = state.copyWith(list: list, positions: positions);
 
-          // Delay for the animation to complete
           await Future.delayed(swipeDuration);
+          if (_operation != SortingEnum.played) return;
         }
       }
     }