iron-range-behavior.html
2.52 KB
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
101
102
103
104
105
106
107
108
109
<!--
@license
Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
Code distributed by Google as part of the polymer project is also
subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
-->
<link rel="import" href="../polymer/polymer.html">
<script>
/**
* `iron-range-behavior` provides the behavior for something with a minimum to maximum range.
*
* @demo demo/index.html
* @polymerBehavior
*/
Polymer.IronRangeBehavior = {
properties: {
/**
* The number that represents the current value.
*/
value: {
type: Number,
value: 0,
notify: true,
reflectToAttribute: true
},
/**
* The number that indicates the minimum value of the range.
*/
min: {
type: Number,
value: 0,
notify: true
},
/**
* The number that indicates the maximum value of the range.
*/
max: {
type: Number,
value: 100,
notify: true
},
/**
* Specifies the value granularity of the range's value.
*/
step: {
type: Number,
value: 1,
notify: true
},
/**
* Returns the ratio of the value.
*/
ratio: {
type: Number,
value: 0,
readOnly: true,
notify: true
},
},
observers: [
'_update(value, min, max, step)'
],
_calcRatio: function(value) {
return (this._clampValue(value) - this.min) / (this.max - this.min);
},
_clampValue: function(value) {
return Math.min(this.max, Math.max(this.min, this._calcStep(value)));
},
_calcStep: function(value) {
/**
* if we calculate the step using
* `Math.round(value / step) * step` we may hit a precision point issue
* eg. 0.1 * 0.2 = 0.020000000000000004
* http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
*
* as a work around we can divide by the reciprocal of `step`
*/
return this.step ? (Math.round(value / this.step) / (1 / this.step)) : value;
},
_validateValue: function() {
var v = this._clampValue(this.value);
this.value = this.oldValue = isNaN(v) ? this.oldValue : v;
return this.value !== v;
},
_update: function() {
this._validateValue();
this._setRatio(this._calcRatio(this.value) * 100);
}
};
</script>