All files / src simpleImgProvider.js

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
 
 
 
 
 
2x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
10x
 
10x
6x
 
4x
1x
1x
 
 
 
 
 
 
 
1x
 
1x
 
 
 
1x
 
 
 
3x
3x
3x
3x
 
 
 
 
 
 
1x
 
 
 
1x
 
 
 
17x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
// @flow
import React from 'react';
import observerStart, { defaultConfig } from './logic/observerStart';
 
// $FlowIgnoreLine:
export const SimpleImgContext = React.createContext({});
 
type State = {
  mountedImages: Set<any>,
  isContextDocumentLoad: boolean,
};
 
export type Config = {
  root?: HTMLElement,
  rootMargin?: string,
  threshold?: number | Array<number>,
};
 
type Props = {
  config?: Object,
  children: any,
};
 
export default class SimpleImgProvider extends React.Component<Props, State> {
  static displayName = 'SimpleImgProvider';
 
  static defaultProps = {
    config: defaultConfig,
  };
 
  state: State = {
    mountedImages: new Set(),
    isContextDocumentLoad: false,
  };
 
  observer = {};
 
  imageLoadRefs: Set<any> = new Set();
 
  componentDidMount() {
    const { config } = this.props;
 
    if (document.readyState === 'complete') {
      this.observer = observerStart.call(this, config);
    } else {
      window.addEventListener('load', () => {
        this.observer = observerStart.call(this, config);
        this.setState({
          isContextDocumentLoad: true,
        });
      });
    }
  }
 
  componentWillUnmount() {
    this.imageLoadRefs.forEach(image => {
      // cancel all loading images;
      image.src = ''; // eslint-disable-line no-param-reassign
    });
  }
 
  appendImageRef = (image: HTMLElement) => this.observer && this.observer.observe && this.observer.observe(image);
 
  removeImageRef = (image: HTMLElement) => {
    // $FlowIgnoreLine:
    this.observer.unobserve(image);
    this.setState(({ mountedImages }) => {
      mountedImages.delete(image);
      return {
        mountedImages,
      };
    });
  };
 
  appendImgLoadingRef = (image: HTMLElement) => {
    this.imageLoadRefs.add(image);
  };
 
  removeImgLoadingRef = (image: HTMLElement) => {
    this.imageLoadRefs.delete(image);
  };
 
  render() {
    return (
      <SimpleImgContext.Provider
        value={{
          ...{
            ...this.state,
            useContext: true,
            appendImageRef: this.appendImageRef,
            removeImageRef: this.removeImageRef,
            appendImgLoadingRef: this.appendImgLoadingRef,
            removeImgLoadingRef: this.removeImgLoadingRef,
          },
        }}
      >
        {this.props.children}
      </SimpleImgContext.Provider>
    );
  }
}