47 строки
1.2 KiB
JavaScript
47 строки
1.2 KiB
JavaScript
/**
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* Copyright (c) 2015-present, Facebook, Inc.
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*
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* This source code is licensed under the MIT license found in the
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* LICENSE file in the root directory of this source tree.
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*
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* @flow
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* @format
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*/
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'use strict';
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const ALLOWED_SCALES = {
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ios: [1, 2, 3],
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};
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function filterPlatformAssetScales(
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platform: string,
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scales: $ReadOnlyArray<number>,
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): $ReadOnlyArray<number> {
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const whitelist = ALLOWED_SCALES[platform];
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if (!whitelist) {
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return scales;
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}
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const result = scales.filter(scale => whitelist.indexOf(scale) > -1);
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if (result.length === 0 && scales.length > 0) {
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// No matching scale found, but there are some available. Ideally we don't
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// want to be in this situation and should throw, but for now as a fallback
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// let's just use the closest larger image
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const maxScale = whitelist[whitelist.length - 1];
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for (const scale of scales) {
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if (scale > maxScale) {
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result.push(scale);
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break;
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}
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}
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// There is no larger scales available, use the largest we have
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if (result.length === 0) {
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result.push(scales[scales.length - 1]);
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}
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}
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return result;
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}
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module.exports = filterPlatformAssetScales;
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