pdf.js/web/annotation_layer_builder.js
Calixte Denizet f316300113 [Annotations] Add some aria-owns in the text layer to link to annotations (bug 1780375)
This patch doesn't structurally change the text layer: it just adds some aria-owns
attributes to some spans.
The aria-owns attribute expect to have an element id, hence it's why it adds back an
id on the element rendering an annotation, but this id is built in using crypto.randomUUID
to avoid any potential issues with the hash in the url.
The elements in the annotation layer are moved into the DOM in order to have them in the
same "order" as they visually are.
The overall goal is to help screen readers to present to the user the annotations as
they visually are and as they come in the text flow.
It is clearly not perfect, but it should improve readability for some people with visual
disabilities.
2022-08-12 14:35:26 +02:00

153 lines
4.9 KiB
JavaScript

/* Copyright 2014 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.
*/
/** @typedef {import("../src/display/api").PDFPageProxy} PDFPageProxy */
// eslint-disable-next-line max-len
/** @typedef {import("../src/display/display_utils").PageViewport} PageViewport */
/** @typedef {import("./interfaces").IDownloadManager} IDownloadManager */
/** @typedef {import("./interfaces").IL10n} IL10n */
/** @typedef {import("./interfaces").IPDFLinkService} IPDFLinkService */
// eslint-disable-next-line max-len
/** @typedef {import("./textaccessibility.js").TextAccessibilityManager} TextAccessibilityManager */
import { AnnotationLayer } from "pdfjs-lib";
import { NullL10n } from "./l10n_utils.js";
/**
* @typedef {Object} AnnotationLayerBuilderOptions
* @property {HTMLDivElement} pageDiv
* @property {PDFPageProxy} pdfPage
* @property {AnnotationStorage} [annotationStorage]
* @property {string} [imageResourcesPath] - Path for image resources, mainly
* for annotation icons. Include trailing slash.
* @property {boolean} renderForms
* @property {IPDFLinkService} linkService
* @property {IDownloadManager} downloadManager
* @property {IL10n} l10n - Localization service.
* @property {boolean} [enableScripting]
* @property {Promise<boolean>} [hasJSActionsPromise]
* @property {Promise<Object<string, Array<Object>> | null>}
* [fieldObjectsPromise]
* @property {Object} [mouseState]
* @property {Map<string, HTMLCanvasElement>} [annotationCanvasMap]
* @property {TextAccessibilityManager} accessibilityManager
*/
class AnnotationLayerBuilder {
/**
* @param {AnnotationLayerBuilderOptions} options
*/
constructor({
pageDiv,
pdfPage,
linkService,
downloadManager,
annotationStorage = null,
imageResourcesPath = "",
renderForms = true,
l10n = NullL10n,
enableScripting = false,
hasJSActionsPromise = null,
fieldObjectsPromise = null,
mouseState = null,
annotationCanvasMap = null,
accessibilityManager = null,
}) {
this.pageDiv = pageDiv;
this.pdfPage = pdfPage;
this.linkService = linkService;
this.downloadManager = downloadManager;
this.imageResourcesPath = imageResourcesPath;
this.renderForms = renderForms;
this.l10n = l10n;
this.annotationStorage = annotationStorage;
this.enableScripting = enableScripting;
this._hasJSActionsPromise = hasJSActionsPromise;
this._fieldObjectsPromise = fieldObjectsPromise;
this._mouseState = mouseState;
this._annotationCanvasMap = annotationCanvasMap;
this._accessibilityManager = accessibilityManager;
this.div = null;
this._cancelled = false;
}
/**
* @param {PageViewport} viewport
* @param {string} intent (default value is 'display')
* @returns {Promise<void>} A promise that is resolved when rendering of the
* annotations is complete.
*/
async render(viewport, intent = "display") {
const [annotations, hasJSActions = false, fieldObjects = null] =
await Promise.all([
this.pdfPage.getAnnotations({ intent }),
this._hasJSActionsPromise,
this._fieldObjectsPromise,
]);
if (this._cancelled || annotations.length === 0) {
return;
}
const parameters = {
viewport: viewport.clone({ dontFlip: true }),
div: this.div,
annotations,
page: this.pdfPage,
imageResourcesPath: this.imageResourcesPath,
renderForms: this.renderForms,
linkService: this.linkService,
downloadManager: this.downloadManager,
annotationStorage: this.annotationStorage,
enableScripting: this.enableScripting,
hasJSActions,
fieldObjects,
mouseState: this._mouseState,
annotationCanvasMap: this._annotationCanvasMap,
accessibilityManager: this._accessibilityManager,
};
if (this.div) {
// If an annotationLayer already exists, refresh its children's
// transformation matrices.
AnnotationLayer.update(parameters);
} else {
// Create an annotation layer div and render the annotations
// if there is at least one annotation.
this.div = document.createElement("div");
this.div.className = "annotationLayer";
this.pageDiv.append(this.div);
parameters.div = this.div;
AnnotationLayer.render(parameters);
this.l10n.translate(this.div);
}
}
cancel() {
this._cancelled = true;
}
hide() {
if (!this.div) {
return;
}
this.div.hidden = true;
}
}
export { AnnotationLayerBuilder };