77 lines
1.8 KiB
TypeScript
77 lines
1.8 KiB
TypeScript
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/*************************************************************
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*
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* Copyright (c) 2021-2022 The MathJax Consortium
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/**
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* @fileoverview Keeps track of usage of font characters and wrappers
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*
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* @author dpvc@mathjax.org (Davide Cervone)
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*/
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/**
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* Class used for tracking usage of font characters or wrappers
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*/
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export class Usage<T> {
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/**
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* The used items.
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*/
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protected used: Set<string> = new Set<string>();
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/**
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* The items marked as used since last update.
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*/
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protected needsUpdate: T[] = [];
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/**
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* @param {T} item The item that has been used
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*/
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public add(item: T) {
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const name = JSON.stringify(item);
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if (!this.used.has(name)) {
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this.needsUpdate.push(item);
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}
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this.used.add(name);
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}
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/**
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* @param {T} item The item to check for being used
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* @return {boolean} True if the item has been used
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*/
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public has(item: T): boolean {
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return this.used.has(JSON.stringify(item));
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}
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/**
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* Clear the usage information
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*/
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public clear() {
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this.used.clear();
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this.needsUpdate = [];
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}
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/**
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* Get the items marked as used since the last update.
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*/
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public update() {
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const update = this.needsUpdate;
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this.needsUpdate = [];
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return update;
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}
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}
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