90 lines
2.3 KiB
JavaScript
90 lines
2.3 KiB
JavaScript
/* Copyright 2024 Mozilla Foundation
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
/**
|
|
* This class manages the interaction of extracting the text content of the page
|
|
* and passing it back to the external service.
|
|
*/
|
|
class PdfTextExtractor {
|
|
/** @type {PDFViewer} */
|
|
#pdfViewer;
|
|
|
|
#externalServices;
|
|
|
|
/**
|
|
* @type {?Promise<string>}
|
|
*/
|
|
#textPromise;
|
|
|
|
#pendingRequests = new Set();
|
|
|
|
constructor(externalServices) {
|
|
this.#externalServices = externalServices;
|
|
|
|
window.addEventListener("requestTextContent", ({ detail }) => {
|
|
this.extractTextContent(detail.requestId);
|
|
});
|
|
}
|
|
|
|
/**
|
|
* The PDF viewer is required to get the page text.
|
|
*
|
|
* @param {PDFViewer | null}
|
|
*/
|
|
setViewer(pdfViewer) {
|
|
this.#pdfViewer = pdfViewer;
|
|
if (this.#pdfViewer && this.#pendingRequests.size) {
|
|
// Handle any pending requests that came in while things were loading.
|
|
for (const pendingRequest of this.#pendingRequests) {
|
|
this.extractTextContent(pendingRequest);
|
|
}
|
|
this.#pendingRequests.clear();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Builds up all of the text from a PDF.
|
|
*
|
|
* @param {number} requestId
|
|
*/
|
|
async extractTextContent(requestId) {
|
|
if (!this.#pdfViewer) {
|
|
this.#pendingRequests.add(requestId);
|
|
return;
|
|
}
|
|
|
|
if (!this.#textPromise) {
|
|
const textPromise = (this.#textPromise = this.#pdfViewer.getAllText());
|
|
|
|
// After the text resolves, cache the text for a little bit in case
|
|
// multiple consumers call it.
|
|
textPromise.then(() => {
|
|
setTimeout(() => {
|
|
if (this.#textPromise === textPromise) {
|
|
this.#textPromise = null;
|
|
}
|
|
}, 5000);
|
|
});
|
|
}
|
|
|
|
this.#externalServices.reportText({
|
|
text: await this.#textPromise,
|
|
requestId,
|
|
});
|
|
}
|
|
}
|
|
|
|
export { PdfTextExtractor };
|