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
110
111
112
113
114
|
/**
* --------------------------------------------------------------------------
* Bootstrap util/scrollBar.js
* Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
* --------------------------------------------------------------------------
*/
import Manipulator from '../dom/manipulator.js'
import SelectorEngine from '../dom/selector-engine.js'
import { isElement } from './index.js'
/**
* Constants
*/
const SELECTOR_FIXED_CONTENT = '.fixed-top, .fixed-bottom, .is-fixed, .sticky-top'
const SELECTOR_STICKY_CONTENT = '.sticky-top'
const PROPERTY_PADDING = 'padding-right'
const PROPERTY_MARGIN = 'margin-right'
/**
* Class definition
*/
class ScrollBarHelper {
constructor() {
this._element = document.body
}
// Public
getWidth() {
// https://developer.mozilla.org/en-US/docs/Web/API/Window/innerWidth#usage_notes
const documentWidth = document.documentElement.clientWidth
return Math.abs(window.innerWidth - documentWidth)
}
hide() {
const width = this.getWidth()
this._disableOverFlow()
// give padding to element to balance the hidden scrollbar width
this._setElementAttributes(this._element, PROPERTY_PADDING, calculatedValue => calculatedValue + width)
// trick: We adjust positive paddingRight and negative marginRight to sticky-top elements to keep showing fullwidth
this._setElementAttributes(SELECTOR_FIXED_CONTENT, PROPERTY_PADDING, calculatedValue => calculatedValue + width)
this._setElementAttributes(SELECTOR_STICKY_CONTENT, PROPERTY_MARGIN, calculatedValue => calculatedValue - width)
}
reset() {
this._resetElementAttributes(this._element, 'overflow')
this._resetElementAttributes(this._element, PROPERTY_PADDING)
this._resetElementAttributes(SELECTOR_FIXED_CONTENT, PROPERTY_PADDING)
this._resetElementAttributes(SELECTOR_STICKY_CONTENT, PROPERTY_MARGIN)
}
isOverflowing() {
return this.getWidth() > 0
}
// Private
_disableOverFlow() {
this._saveInitialAttribute(this._element, 'overflow')
this._element.style.overflow = 'hidden'
}
_setElementAttributes(selector, styleProperty, callback) {
const scrollbarWidth = this.getWidth()
const manipulationCallBack = element => {
if (element !== this._element && window.innerWidth > element.clientWidth + scrollbarWidth) {
return
}
this._saveInitialAttribute(element, styleProperty)
const calculatedValue = window.getComputedStyle(element).getPropertyValue(styleProperty)
element.style.setProperty(styleProperty, `${callback(Number.parseFloat(calculatedValue))}px`)
}
this._applyManipulationCallback(selector, manipulationCallBack)
}
_saveInitialAttribute(element, styleProperty) {
const actualValue = element.style.getPropertyValue(styleProperty)
if (actualValue) {
Manipulator.setDataAttribute(element, styleProperty, actualValue)
}
}
_resetElementAttributes(selector, styleProperty) {
const manipulationCallBack = element => {
const value = Manipulator.getDataAttribute(element, styleProperty)
// We only want to remove the property if the value is `null`; the value can also be zero
if (value === null) {
element.style.removeProperty(styleProperty)
return
}
Manipulator.removeDataAttribute(element, styleProperty)
element.style.setProperty(styleProperty, value)
}
this._applyManipulationCallback(selector, manipulationCallBack)
}
_applyManipulationCallback(selector, callBack) {
if (isElement(selector)) {
callBack(selector)
return
}
for (const sel of SelectorEngine.find(selector, this._element)) {
callBack(sel)
}
}
}
export default ScrollBarHelper
|
