Fixed strong mode errors and warnings reachable from lib/observe.dart

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;
+      : isInsert = false,
+        isRemove = false;
 
   MapChangeRecord.insert(this.key, this.newValue)
-      : isInsert = true, isRemove = false, oldValue = null;
+      : isInsert = true,
+        isRemove = false,
+        oldValue = null;
 
   MapChangeRecord.remove(this.key, this.oldValue)
-      : isInsert = false, isRemove = true, newValue = null;
+      : 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.
@@ skipping 15 matching lines @@
   /// [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;
+    ObservableMap<K, V> 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 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];
@@ skipping 13 matching lines @@
       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; });
+    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);
+    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;
@@ skipping 15 matching lines @@
   // 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));
   }
 }