collection_notifiers library

Collection classes with ChangeNotifier and ValueListenable support.

This library provides reactive collection wrappers that notify listeners when their contents change, enabling efficient UI rebuilds in Flutter.

Available Notifiers

• ListNotifier - A reactive List implementation
• MapNotifier - A reactive Map implementation
• SetNotifier - A reactive Set implementation
• QueueNotifier - A reactive Queue implementation

Usage with ValueListenableBuilder

final items = ListNotifier<String>(['a', 'b', 'c']);

ValueListenableBuilder<List<String>>(
  valueListenable: items,
  builder: (context, value, child) {
    return ListView.builder(
      itemCount: value.length,
      itemBuilder: (context, index) => Text(value[index]),
    );
  },
);

// Mutations automatically trigger rebuilds
items.add('d');

Notification Behavior

Methods only call ChangeNotifier.notifyListeners when the collection actually changes. For example:

• set.add(existingElement) - No notification (element already exists)
• map['key'] = sameValue - No notification (value unchanged)
• list.clear() on empty list - No notification (nothing to clear)

This optimization prevents unnecessary widget rebuilds.

Classes

ListNotifier<E>

A List implementation that notifies listeners when modified.

MapNotifier<K, V>

A Map implementation that notifies listeners when modified.

QueueNotifier<E>

A Queue implementation that notifies listeners when modified.

SetNotifier<E>

A Set implementation that notifies listeners when modified.