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lib/util/list_extensions.dart

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+import 'package:collection/collection.dart';
+
+extension ListExtensions<T> on List<T> {
+  List<T> replace(T entry) {
+    var tempList = toList();
+    final index = indexOf(entry);
+    tempList.removeAt(index);
+    tempList.insert(index, entry);
+    return tempList;
+  }
+
+  List<T> toggle(T entry) {
+    var tempList = toList();
+    if (contains(entry)) {
+      return tempList..remove(entry);
+    } else {
+      return tempList..add(entry);
+    }
+  }
+
+  bool containsAny(Iterable<T> entries) {
+    for (var value in entries) {
+      if (contains(value)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  List<T> toggleUnique(T entry) => toggle(entry).toSet().toList();
+
+  List<T> random() {
+    List<T> tempList = this;
+    tempList.shuffle();
+    return tempList;
+  }
+
+  List<T> uniqueBy(dynamic Function(T value) keySelector) {
+    final Map<dynamic, T> uniqueMap = {};
+
+    for (var item in this) {
+      final key = keySelector(item);
+      if (!uniqueMap.containsKey(key)) {
+        uniqueMap[key] = item;
+      }
+    }
+
+    return uniqueMap.values.toList();
+  }
+
+  Iterable<List<T>> chunk(int size) sync* {
+    if (size <= 0) {
+      throw ArgumentError('Chunk size must be greater than zero.');
+    }
+
+    final iterator = this.iterator;
+    while (iterator.moveNext()) {
+      final chunk = <T>[];
+      for (var i = 0; i < size; i++) {
+        if (!iterator.moveNext()) {
+          break;
+        }
+        chunk.add(iterator.current);
+      }
+      yield chunk;
+    }
+  }
+
+  T? nextOrNull(T item) {
+    int indexOf = this.indexOf(item);
+    if (indexOf + 1 >= length) return null;
+    return elementAtOrNull(indexOf + 1);
+  }
+
+  T? previousOrNull(T item) {
+    int indexOf = this.indexOf(item);
+    if (indexOf - 1 < 0) return null;
+    return elementAtOrNull(indexOf - 1);
+  }
+
+  T? nextWhereOrNull(bool Function(T element) test) {
+    final indexOf = indexWhere((element) => test(element));
+    if (indexOf + 1 < length) return null;
+    return elementAtOrNull(indexOf + 1);
+  }
+
+  T? previousWhereOrNull(bool Function(T element) test) {
+    final indexOf = indexWhere((element) => test(element));
+    if (indexOf - 1 < length) return null;
+    return elementAtOrNull(indexOf - 1);
+  }
+}