Update charted to 0.4.8 and roll

packages/observe/lib/src/observable_map.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library observe.src.observable_map;
-
-import 'dart:collection';
-import 'package:observe/observe.dart';
-
-
-// TODO(jmesserly): this needs to be faster. We currently require multiple
-// lookups per key to get the old value.
-// TODO(jmesserly): this doesn't implement the precise interfaces like
-// LinkedHashMap, SplayTreeMap or HashMap. However it can use them for the
-// backing store.
-
-// TODO(jmesserly): should we summarize map changes like we do for list changes?
-class MapChangeRecord<K, V> extends ChangeRecord {
-  // TODO(jmesserly): we could store this more compactly if it matters, with
-  // subtypes for inserted and removed.
-
-  /// The map key that changed.
-  final K key;
-
-  /// The previous value associated with this key.
-  final V oldValue;
-
-  /// The new value associated with this key.
-  final V newValue;
-
-  /// True if this key was inserted.
-  final bool isInsert;
-
-  /// True if this key was removed.
-  final bool isRemove;
-
-  MapChangeRecord(this.key, this.oldValue, this.newValue)
-      : isInsert = false, isRemove = false;
-
-  MapChangeRecord.insert(this.key, this.newValue)
-      : isInsert = true, isRemove = false, oldValue = null;
-
-  MapChangeRecord.remove(this.key, this.oldValue)
-      : isInsert = false, isRemove = true, newValue = null;
-
-  String toString() {
-    var kind = isInsert ? 'insert' : isRemove ? 'remove' : 'set';
-    return '#<MapChangeRecord $kind $key from: $oldValue to: $newValue>';
-  }
-}
-
-/// Represents an observable map of model values. If any items are added,
-/// removed, or replaced, then observers that are listening to [changes]
-/// will be notified.
-class ObservableMap<K, V> extends ChangeNotifier implements Map<K, V> {
-  final Map<K, V> _map;
-
-  /// Creates an observable map.
-  ObservableMap() : _map = new HashMap<K, V>();
-
-  /// Creates a new observable map using a [LinkedHashMap].
-  ObservableMap.linked() : _map = new LinkedHashMap<K, V>();
-
-  /// Creates a new observable map using a [SplayTreeMap].
-  ObservableMap.sorted() : _map = new SplayTreeMap<K, V>();
-
-  /// Creates an observable map that contains all key value pairs of [other].
-  /// It will attempt to use the same backing map type if the other map is a
-  /// [LinkedHashMap], [SplayTreeMap], or [HashMap]. Otherwise it defaults to
-  /// [HashMap].
-  ///
-  /// Note this will perform a shallow conversion. If you want a deep conversion
-  /// you should use [toObservable].
-  factory ObservableMap.from(Map<K, V> other) {
-    return new ObservableMap<K, V>.createFromType(other)..addAll(other);
-  }
-
-  /// Like [ObservableMap.from], but creates an empty map.
-  factory ObservableMap.createFromType(Map<K, V> other) {
-    ObservableMap result;
-    if (other is SplayTreeMap) {
-      result = new ObservableMap<K, V>.sorted();
-    } else if (other is LinkedHashMap) {
-      result = new ObservableMap<K, V>.linked();
-    } else {
-      result = new ObservableMap<K, V>();
-    }
-    return result;
-  }
-
-  @reflectable Iterable<K> get keys => _map.keys;
-
-  @reflectable Iterable<V> get values => _map.values;
-
-  @reflectable int get length =>_map.length;
-
-  @reflectable bool get isEmpty => length == 0;
-
-  @reflectable bool get isNotEmpty => !isEmpty;
-
-  @reflectable bool containsValue(Object value) => _map.containsValue(value);
-
-  @reflectable bool containsKey(Object key) => _map.containsKey(key);
-
-  @reflectable V operator [](Object key) => _map[key];
-
-  @reflectable void operator []=(K key, V value) {
-    if (!hasObservers) {
-      _map[key] = value;
-      return;
-    }
-
-    int len = _map.length;
-    V oldValue = _map[key];
-
-    _map[key] = value;
-
-    if (len != _map.length) {
-      notifyPropertyChange(#length, len, _map.length);
-      notifyChange(new MapChangeRecord.insert(key, value));
-      _notifyKeysValuesChanged();
-    } else if (oldValue != value) {
-      notifyChange(new MapChangeRecord(key, oldValue, value));
-      _notifyValuesChanged();
-    }
-  }
-
-  void addAll(Map<K, V> other) {
-    other.forEach((K key, V value) { this[key] = value; });
-  }
-
-  V putIfAbsent(K key, V ifAbsent()) {
-    int len = _map.length;
-    V result = _map.putIfAbsent(key, ifAbsent);
-    if (hasObservers && len != _map.length) {
-      notifyPropertyChange(#length, len, _map.length);
-      notifyChange(new MapChangeRecord.insert(key, result));
-      _notifyKeysValuesChanged();
-    }
-    return result;
-  }
-
-  V remove(Object key) {
-    int len = _map.length;
-    V result =  _map.remove(key);
-    if (hasObservers && len != _map.length) {
-      notifyChange(new MapChangeRecord.remove(key, result));
-      notifyPropertyChange(#length, len, _map.length);
-      _notifyKeysValuesChanged();
-    }
-    return result;
-  }
-
-  void clear() {
-    int len = _map.length;
-    if (hasObservers && len > 0) {
-      _map.forEach((key, value) {
-        notifyChange(new MapChangeRecord.remove(key, value));
-      });
-      notifyPropertyChange(#length, len, 0);
-      _notifyKeysValuesChanged();
-    }
-    _map.clear();
-  }
-
-  void forEach(void f(K key, V value)) => _map.forEach(f);
-
-  String toString() => Maps.mapToString(this);
-
-  // Note: we don't really have a reasonable old/new value to use here.
-  // But this should fix "keys" and "values" in templates with minimal overhead.
-  void _notifyKeysValuesChanged() {
-    notifyChange(new PropertyChangeRecord(this, #keys, null, null));
-    _notifyValuesChanged();
-  }
-
-  void _notifyValuesChanged() {
-    notifyChange(new PropertyChangeRecord(this, #values, null, null));
-  }
-}