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74db085794
Currently the viewer uses semi-private `EventBus.prototype.{_on, _off}` methods, to try and ensure that all internal viewer state is updated *before* any "external" listeners are invoked.
For all use-cases outside of the viewer, e.g in the integration-tests, the `EventBus.prototype.{on, off}` methods are supposed to be used instead.
Unfortunately this isn't currently enforced in any way, except (hopefully) during review, and generally speaking it's not really possible to prevent the semi-private methods being used (e.g. by third-party users).
Hence this patch adds a new `INTERNAL_EVT` property which is *not* exposed anywhere (neither in the API nor globally), and whose value is generated at build-time, that the viewer uses to mark its `EventBus` listeners are internal.
This allows us to remove the semi-private `EventBus` methods, which helps to simplify that class a little bit.
87 lines
2.2 KiB
JavaScript
87 lines
2.2 KiB
JavaScript
/* Copyright 2024 Mozilla Foundation
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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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import { internalOpt } from "./internal_evt.js";
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/**
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* This class manages the interaction of extracting the text content of the page
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* and passing it back to the external service.
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*/
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class PdfTextExtractor {
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/** @type {BaseExternalServices} */
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#externalServices;
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/** @type {?Promise<string>} */
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#textPromise;
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#capability = Promise.withResolvers();
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constructor(externalServices, pdfViewer, eventBus) {
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this.#externalServices = externalServices;
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eventBus.on(
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"pagesinit",
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() => {
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this.#capability.resolve(pdfViewer);
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},
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internalOpt
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);
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eventBus.on(
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"pagesdestroy",
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() => {
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this.#capability.reject(new Error("pagesdestroy"));
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this.#textPromise = null;
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this.#capability = Promise.withResolvers();
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},
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internalOpt
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);
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window.addEventListener("requestTextContent", ({ detail }) => {
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this.extractTextContent(detail.requestId);
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});
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}
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/**
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* Builds up all of the text from a PDF.
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*
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* @param {number} requestId
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*/
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async extractTextContent(requestId) {
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if (!this.#textPromise) {
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const textPromise = (this.#textPromise = this.#capability.promise.then(
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pdfViewer => pdfViewer.getAllText()
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));
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// After the text resolves, cache the text for a little bit in case
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// multiple consumers call it.
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textPromise.then(() => {
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setTimeout(() => {
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if (this.#textPromise === textPromise) {
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this.#textPromise = null;
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}
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}, 5000);
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});
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}
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this.#externalServices.reportText({
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text: await this.#textPromise,
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requestId,
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});
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}
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}
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export { PdfTextExtractor };
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