Make Stocks app search actually search

sky/framework/components/input.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import '../editing/editable_string.dart';
 import '../editing/editable_text.dart';
 import '../editing/keyboard.dart';
 import '../fn.dart';
 import '../theme/colors.dart';
 
@@ skipping 17 matching lines @@
     left: 8px;
     color: ${Grey[200]};
     position: absolute;'''
   );
 
   static final String _focusedInlineStyle = '''
     padding: 7px;
     border-bottom: 2px solid ${Blue[500]};''';
 
   ValueChanged onChanged;
-  String value;
   String placeholder;
   bool focused = false;
 
+  String _value = '';
   bool _isAttachedToKeyboard = false;
   EditableString _editableValue;
 
-  Input({Object key, this.value: '', this.placeholder, this.focused})
+  Input({Object key,
+         this.placeholder,
+         this.onChanged,
+         this.focused})
       : super(key: key, stateful: true) {
-    _editableValue = new EditableString(text: value,
+    _editableValue = new EditableString(text: _value,
                                         onUpdated: _handleTextUpdated);
   }
 
   void _handleTextUpdated() {
     setState(() {});
-    if (value != _editableValue.text) {
-      value = _editableValue.text;
+    if (_value != _editableValue.text) {
+      _value = _editableValue.text;
       if (onChanged != null)
-        onChanged(value);
+        onChanged(_value);
     }
   }
 
   void didUnmount() {
     if (_isAttachedToKeyboard)
       keyboard.hide();
   }
 
   Node build() {
     if (focused && !_isAttachedToKeyboard) {
       keyboard.show(_editableValue.stub);
       _isAttachedToKeyboard = true;
     }
 
     List<Node> children = [];
 
-    if (placeholder != null && value.isEmpty) {
+    if (placeholder != null && _value.isEmpty) {
       children.add(new Container(
           style: _placeholderStyle,
           children: [new Text(placeholder)]
       ));
     }
 
     children.add(new EditableText(value: _editableValue, focused: focused));
 
     return new Container(
       style: _style,
       inlineStyle: focused ? _focusedInlineStyle : null,
       children: children
     );
   }
 }