Move observe to observe package

pkg/polymer/lib/observe.dart

Index: pkg/polymer/lib/observe.dart
diff --git a/pkg/polymer/lib/observe.dart b/pkg/polymer/lib/observe.dart
deleted file mode 100644
index 0a02a9071e38049e3329f58ed15936134194cea9..0000000000000000000000000000000000000000
--- a/pkg/polymer/lib/observe.dart
+++ /dev/null
@@ -1,124 +0,0 @@
-// 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.
-
-/**
- * Helpers for observable objects.
- * Intended for use with `package:observe`.
- */
-library polymer.observe;
-
-import 'dart:async';
-import 'package:observe/observe.dart';
-
-const _VALUE = const Symbol('value');
-
-/**
- * Forwards an observable property from one object to another. For example:
- *
- *     class MyModel extends ObservableBase {
- *       StreamSubscription _sub;
- *       MyOtherModel _otherModel;
- *
- *       MyModel() {
- *         ...
- *         _sub = bindProperty(_otherModel, const Symbol('value'),
- *             () => notifyProperty(this, const Symbol('prop'));
- *       }
- *
- *       String get prop => _otherModel.value;
- *       set prop(String value) { _otherModel.value = value; }
- *     }
- *
- * See also [notifyProperty].
- */
-StreamSubscription bindProperty(Observable source, Symbol sourceName,
-    void callback()) {
-  return source.changes.listen((records) {
-    for (var record in records) {
-      if (record.changes(sourceName)) {
-        callback();
-      }
-    }
-  });
-}
-
-/**
- * Notify the property change. Shorthand for:
- *
- *     target.notifyChange(new PropertyChangeRecord(targetName));
- */
-void notifyProperty(Observable target, Symbol targetName) {
-  target.notifyChange(new PropertyChangeRecord(targetName));
-}
-
-
-// Inspired by ArrayReduction at:
-// https://raw.github.com/rafaelw/ChangeSummary/master/util/array_reduction.js
-// The main difference is we support anything on the rich Dart Iterable API.
-
-/**
- * Observes a path starting from each item in the list.
- */
-class ListPathObserver<E, P> extends ChangeNotifierBase {
-  final ObservableList<E> list;
-  final String _itemPath;
-  final List<PathObserver> _observers = <PathObserver>[];
-  final List<StreamSubscription> _subs = <StreamSubscription>[];
-  StreamSubscription _sub;
-  bool _scheduled = false;
-  Iterable<P> _value;
-
-  ListPathObserver(this.list, String path)
-      : _itemPath = path {
-
-    _sub = list.changes.listen((records) {
-      for (var record in records) {
-        if (record is ListChangeRecord) {
-          _observeItems(record.addedCount - record.removedCount);
-        }
-      }
-      _scheduleReduce(null);
-    });
-
-    _observeItems(list.length);
-    _reduce();
-  }
-
-  Iterable<P> get value => _value;
-
-  void dispose() {
-    if (_sub != null) _sub.cancel();
-    _subs.forEach((s) => s.cancel());
-    _subs.clear();
-  }
-
-  void _reduce() {
-    _scheduled = false;
-    _value = _observers.map((o) => o.value);
-    notifyChange(new PropertyChangeRecord(_VALUE));
-  }
-
-  void _scheduleReduce(_) {
-    if (_scheduled) return;
-    _scheduled = true;
-    runAsync(_reduce);
-  }
-
-  void _observeItems(int lengthAdjust) {
-    if (lengthAdjust > 0) {
-      for (int i = 0; i < lengthAdjust; i++) {
-        int len = _observers.length;
-        var pathObs = new PathObserver(list, '$len.$_itemPath');
-        _subs.add(pathObs.changes.listen(_scheduleReduce));
-        _observers.add(pathObs);
-      }
-    } else if (lengthAdjust < 0) {
-      for (int i = 0; i < -lengthAdjust; i++) {
-        _subs.removeLast().cancel();
-      }
-      int len = _observers.length;
-      _observers.removeRange(len + lengthAdjust, len);
-    }
-  }
-}