2a09d1a4
 liuqimichale
添加宜春 天水 宣化
|
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
|
import {Map} from './shims/es6-collections.js';
import ResizeObserverController from './ResizeObserverController.js';
import ResizeObserverSPI from './ResizeObserverSPI.js';
// Registry of internal observers. If WeakMap is not available use current shim
// for the Map collection as it has all required methods and because WeakMap
// can't be fully polyfilled anyway.
const observers = typeof WeakMap !== 'undefined' ? new WeakMap() : new Map();
/**
* ResizeObserver API. Encapsulates the ResizeObserver SPI implementation
* exposing only those methods and properties that are defined in the spec.
*/
class ResizeObserver {
/**
* Creates a new instance of ResizeObserver.
*
* @param {ResizeObserverCallback} callback - Callback that is invoked when
* dimensions of the observed elements change.
*/
constructor(callback) {
if (!(this instanceof ResizeObserver)) {
throw new TypeError('Cannot call a class as a function.');
}
if (!arguments.length) {
throw new TypeError('1 argument required, but only 0 present.');
}
const controller = ResizeObserverController.getInstance();
const observer = new ResizeObserverSPI(callback, controller, this);
observers.set(this, observer);
}
}
// Expose public methods of ResizeObserver.
[
'observe',
'unobserve',
'disconnect'
].forEach(method => {
ResizeObserver.prototype[method] = function () {
return observers.get(this)[method](...arguments);
};
});
export default ResizeObserver;
|
