blob: ff044307e5ad9003ec04d6d4ee892e4ad8a87582 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
|
// Copyright 2012 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Provide definition of an observer. This is meant to
* be used with {@code goog.labs.observe.Observable}.
*
* This file also provides convenient functions to compare and create
* Observer objects.
*
*/
goog.provide('goog.labs.observe.Observer');
/**
* A class implementing {@code Observer} may be informed of changes in
* observable object.
* @see {goog.labs.observe.Observable}
* @interface
*/
goog.labs.observe.Observer = function() {};
/**
* Notifies the observer of changes to the observable object.
* @param {!goog.labs.observe.Notice} notice The notice object.
*/
goog.labs.observe.Observer.prototype.notify;
/**
* Whether this observer is equal to the given observer.
* @param {!goog.labs.observe.Observer} observer The observer to compare with.
* @return {boolean} Whether the two observers are equal.
*/
goog.labs.observe.Observer.prototype.equals;
/**
* @param {!goog.labs.observe.Observer} observer1 Observer to compare.
* @param {!goog.labs.observe.Observer} observer2 Observer to compare.
* @return {boolean} Whether observer1 and observer2 are equal, as
* determined by the first observer1's {@code equals} method.
*/
goog.labs.observe.Observer.equals = function(observer1, observer2) {
return observer1 == observer2 || observer1.equals(observer2);
};
/**
* Creates an observer that calls the given function.
* @param {function(!goog.labs.observe.Notice)} fn Function to be converted.
* @param {!Object=} opt_scope Optional scope to execute the function.
* @return {!goog.labs.observe.Observer} An observer object.
*/
goog.labs.observe.Observer.fromFunction = function(fn, opt_scope) {
return new goog.labs.observe.Observer.FunctionObserver_(fn, opt_scope);
};
/**
* An observer that calls the given function on {@code notify}.
* @param {function(!goog.labs.observe.Notice)} fn Function to delegate to.
* @param {!Object=} opt_scope Optional scope to execute the function.
* @constructor
* @implements {goog.labs.observe.Observer}
* @private
*/
goog.labs.observe.Observer.FunctionObserver_ = function(fn, opt_scope) {
this.fn_ = fn;
this.scope_ = opt_scope;
};
/** @override */
goog.labs.observe.Observer.FunctionObserver_.prototype.notify = function(
notice) {
this.fn_.call(this.scope_, notice);
};
/** @override */
goog.labs.observe.Observer.FunctionObserver_.prototype.equals = function(
observer) {
return this.fn_ === observer.fn_ && this.scope_ === observer.scope_;
};
|
