48 lines
1.0 KiB
TypeScript
48 lines
1.0 KiB
TypeScript
import Scrollable from "../components/scrollable";
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import { safeAssign } from "./object";
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export default class ScrollableLoader {
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public loading = false;
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private scrollable: Scrollable;
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private getPromise: () => Promise<any>;
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private promise: Promise<any>;
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private loaded = false;
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constructor(options: {
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scrollable: ScrollableLoader['scrollable'],
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getPromise: ScrollableLoader['getPromise']
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}) {
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safeAssign(this, options);
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options.scrollable.onScrolledBottom = () => {
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this.load();
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};
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}
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public load() {
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if(this.loaded) {
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return Promise.resolve();
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}
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if(this.loading) {
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return this.promise;
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}
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this.loading = true;
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this.promise = this.getPromise().then(done => {
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this.loading = false;
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this.promise = undefined;
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if(done) {
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this.loaded = true;
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this.scrollable.onScrolledBottom = null;
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} else {
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this.scrollable.checkForTriggers();
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}
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}, () => {
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this.promise = undefined;
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this.loading = false;
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});
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}
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}
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