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Issue 20863002: Introduce boot.js: this finally makes it possible to load and run Todomvc (Closed) Base URL: git@github.com:dart-lang/web-ui.git@master
Patch Set: Created 7 years, 4 months ago
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1 // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file 1 // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
2 // for details. All rights reserved. Use of this source code is governed by a 2 // for details. All rights reserved. Use of this source code is governed by a
3 // BSD-style license that can be found in the LICENSE file. 3 // BSD-style license that can be found in the LICENSE file.
4 4
5 /** 5 /**
6 * Helpers for observable objects. 6 * Helpers for observable objects.
7 * Intended for use with `package:mdv_observe`. 7 * Intended for use with `package:mdv_observe`.
8 */ 8 */
9 library polymer.observe; 9 library polymer.observe;
10 10
11 import 'dart:async'; 11 import 'dart:async';
12 // TODO(jmesserly): PathObserver should be in mdv_observe. 12 // TODO(jmesserly): PathObserver should be in mdv_observe.
13 import 'dart:html' show PathObserver; 13 import 'dart:html' show PathObserver;
14 import 'package:observe/observe.dart'; 14 import 'package:observe/observe.dart';
15 15
16 /**
17 * Use `@observable` to make a property observable.
18 * The overhead will be minimal unless they are actually being observed.
19 */
20 const observable = const _ObservableAnnotation();
21
22 /**
23 * The type of the `@observable` annotation.
24 *
25 * Library private because you should be able to use the [observable] field
26 * to get the one and only instance. We could make it public though, if anyone
27 * needs it for some reason.
28 */
29 class _ObservableAnnotation {
30 const _ObservableAnnotation();
31 }
32
33 // Inspired by ArrayReduction at: 16 // Inspired by ArrayReduction at:
34 // https://raw.github.com/rafaelw/ChangeSummary/master/util/array_reduction.js 17 // https://raw.github.com/rafaelw/ChangeSummary/master/util/array_reduction.js
35 // The main difference is we support anything on the rich Dart Iterable API. 18 // The main difference is we support anything on the rich Dart Iterable API.
36 19
37 const _VALUE = const Symbol('value'); 20 const _VALUE = const Symbol('value');
38 21
39 /** 22 /**
40 * Forwards an observable property from one object to another. For example: 23 * Forwards an observable property from one object to another. For example:
41 * 24 *
42 * class MyModel extends ObservableBase { 25 * class MyModel extends ObservableBase {
(...skipping 21 matching lines...) Expand all
64 } 47 }
65 } 48 }
66 }); 49 });
67 } 50 }
68 51
69 /** 52 /**
70 * Notify the property change. Shorthand for: 53 * Notify the property change. Shorthand for:
71 * 54 *
72 * target.notifyChange(new PropertyChangeRecord(targetName)); 55 * target.notifyChange(new PropertyChangeRecord(targetName));
73 */ 56 */
74 void notifyProperty(ObservableMixin target, Symbol targetName) { 57 void notifyProperty(Observable target, Symbol targetName) {
75 target.notifyChange(new PropertyChangeRecord(targetName)); 58 target.notifyChange(new PropertyChangeRecord(targetName));
76 } 59 }
77 60
78 61
79 /** 62 /**
80 * Observes a path starting from each item in the list. 63 * Observes a path starting from each item in the list.
81 */ 64 */
82 class ListPathObserver<E, P> extends ObservableBase { 65 class ListPathObserver<E, P> extends ChangeNotifierBase {
83 final ObservableList<E> list; 66 final ObservableList<E> list;
84 final String _itemPath; 67 final String _itemPath;
85 final List<PathObserver> _observers = <PathObserver>[]; 68 final List<PathObserver> _observers = <PathObserver>[];
86 final List<StreamSubscription> _subs = <StreamSubscription>[]; 69 final List<StreamSubscription> _subs = <StreamSubscription>[];
87 StreamSubscription _sub; 70 StreamSubscription _sub;
88 bool _scheduled = false; 71 bool _scheduled = false;
89 Iterable<P> _value; 72 Iterable<P> _value;
90 73
91 ListPathObserver(this.list, String path) 74 ListPathObserver(this.list, String path)
92 : _itemPath = path { 75 : _itemPath = path {
(...skipping 21 matching lines...) Expand all
114 97
115 void _reduce() { 98 void _reduce() {
116 _scheduled = false; 99 _scheduled = false;
117 _value = _observers.map((o) => o.value); 100 _value = _observers.map((o) => o.value);
118 notifyChange(new PropertyChangeRecord(_VALUE)); 101 notifyChange(new PropertyChangeRecord(_VALUE));
119 } 102 }
120 103
121 void _scheduleReduce(_) { 104 void _scheduleReduce(_) {
122 if (_scheduled) return; 105 if (_scheduled) return;
123 _scheduled = true; 106 _scheduled = true;
124 queueChangeRecords(_reduce); 107 runAsync(_reduce);
125 } 108 }
126 109
127 _observeItems(int lengthAdjust) { 110 _observeItems(int lengthAdjust) {
128 if (lengthAdjust > 0) { 111 if (lengthAdjust > 0) {
129 for (int i = 0; i < lengthAdjust; i++) { 112 for (int i = 0; i < lengthAdjust; i++) {
130 int len = _observers.length; 113 int len = _observers.length;
131 var pathObs = new PathObserver(list, '$len.$_itemPath'); 114 var pathObs = new PathObserver(list, '$len.$_itemPath');
132 _subs.add(pathObs.values.listen(_scheduleReduce)); 115 _subs.add(pathObs.changes.listen(_scheduleReduce));
133 _observers.add(pathObs); 116 _observers.add(pathObs);
134 } 117 }
135 } else if (lengthAdjust < 0) { 118 } else if (lengthAdjust < 0) {
136 for (int i = 0; i < -lengthAdjust; i++) { 119 for (int i = 0; i < -lengthAdjust; i++) {
137 _subs.removeLast().cancel(); 120 _subs.removeLast().cancel();
138 } 121 }
139 int len = _observers.length; 122 int len = _observers.length;
140 _observers.removeRange(len + lengthAdjust, len); 123 _observers.removeRange(len + lengthAdjust, len);
141 } 124 }
142 } 125 }
143
144 setValueWorkaround(key, value) {}
145 getValueWorkaround(key) => key == _VALUE ? value : null;
146 } 126 }
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