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
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
|
import React from 'react';
import ImmutablePropTypes from 'react-immutable-proptypes';
import { ScrollContainer } from 'react-router-scroll';
import PropTypes from 'prop-types';
import StatusContainer from '../containers/status_container';
import LoadMore from './load_more';
import ImmutablePureComponent from 'react-immutable-pure-component';
class StatusList extends ImmutablePureComponent {
static propTypes = {
scrollKey: PropTypes.string.isRequired,
statusIds: ImmutablePropTypes.list.isRequired,
onScrollToBottom: PropTypes.func,
onScrollToTop: PropTypes.func,
onScroll: PropTypes.func,
shouldUpdateScroll: PropTypes.func,
isLoading: PropTypes.bool,
isUnread: PropTypes.bool,
hasMore: PropTypes.bool,
prepend: PropTypes.node,
emptyMessage: PropTypes.node,
};
static defaultProps = {
trackScroll: true,
};
state = {
isIntersecting: {},
intersectionCount: 0,
}
statusRefQueue = []
handleScroll = (e) => {
const { scrollTop, scrollHeight, clientHeight } = e.target;
const offset = scrollHeight - scrollTop - clientHeight;
this._oldScrollPosition = scrollHeight - scrollTop;
if (250 > offset && this.props.onScrollToBottom && !this.props.isLoading) {
this.props.onScrollToBottom();
} else if (scrollTop < 100 && this.props.onScrollToTop) {
this.props.onScrollToTop();
} else if (this.props.onScroll) {
this.props.onScroll();
}
}
componentDidMount () {
this.attachScrollListener();
this.attachIntersectionObserver();
}
componentDidUpdate (prevProps) {
if ((prevProps.statusIds.size < this.props.statusIds.size && prevProps.statusIds.first() !== this.props.statusIds.first() && !!this._oldScrollPosition) && this.node.scrollTop > 0) {
this.node.scrollTop = this.node.scrollHeight - this._oldScrollPosition;
}
}
componentWillUnmount () {
this.detachScrollListener();
this.detachIntersectionObserver();
}
attachIntersectionObserver () {
const onIntersection = (entries) => {
this.setState(state => {
entries.forEach(entry => {
const statusId = entry.target.getAttribute('data-id');
state.isIntersecting[statusId] = entry.isIntersecting;
});
// isIntersecting is a map of DOM data-id's to booleans (true for
// intersecting, false for non-intersecting).
//
// We always want to return true in shouldComponentUpdate() if
// this object changes, because onIntersection() is only called if
// something has changed.
//
// Now, we *could* use an immutable map or some other structure to
// diff the full map, but that would be pointless because the browser
// has already informed us that something has changed. So we can just
// use a regular object, which will be diffed by ImmutablePureComponent
// based on reference equality (i.e. it's always "unchanged") and
// then we just increment intersectionCount to force a change.
return {
isIntersecting: state.isIntersecting,
intersectionCount: state.intersectionCount + 1,
};
});
};
const options = {
root: this.node,
rootMargin: '300% 0px',
};
this.intersectionObserver = new IntersectionObserver(onIntersection, options);
if (this.statusRefQueue.length) {
this.statusRefQueue.forEach(node => this.intersectionObserver.observe(node));
this.statusRefQueue = [];
}
}
detachIntersectionObserver () {
this.intersectionObserver.disconnect();
}
attachScrollListener () {
this.node.addEventListener('scroll', this.handleScroll);
}
detachScrollListener () {
this.node.removeEventListener('scroll', this.handleScroll);
}
setRef = (c) => {
this.node = c;
}
handleStatusRef = (node) => {
if (node && this.intersectionObserver) {
const statusId = node.getAttribute('data-id');
this.intersectionObserver.observe(node);
} else {
this.statusRefQueue.push(node);
}
}
handleLoadMore = (e) => {
e.preventDefault();
this.props.onScrollToBottom();
}
render () {
const { statusIds, onScrollToBottom, scrollKey, shouldUpdateScroll, isLoading, isUnread, hasMore, prepend, emptyMessage } = this.props;
const { isIntersecting } = this.state;
let loadMore = null;
let scrollableArea = null;
let unread = null;
if (!isLoading && statusIds.size > 0 && hasMore) {
loadMore = <LoadMore onClick={this.handleLoadMore} />;
}
if (isUnread) {
unread = <div className='status-list__unread-indicator' />;
}
if (isLoading || statusIds.size > 0 || !emptyMessage) {
scrollableArea = (
<div className='scrollable' ref={this.setRef}>
{unread}
<div className='status-list'>
{prepend}
{statusIds.map((statusId) => {
return <StatusContainer key={statusId} id={statusId} isIntersecting={isIntersecting[statusId]} onRef={this.handleStatusRef} />;
})}
{loadMore}
</div>
</div>
);
} else {
scrollableArea = (
<div className='empty-column-indicator' ref={this.setRef}>
{emptyMessage}
</div>
);
}
return (
<ScrollContainer scrollKey={scrollKey} shouldUpdateScroll={shouldUpdateScroll}>
{scrollableArea}
</ScrollContainer>
);
}
}
export default StatusList;
|
