pdf.js/web/pdf_thumbnail_viewer.js
Jonas Jenwald 61186698c3 Replace the remaining occurences of instanceof Array with Array.isArray()
*Follow-up to PRs 8864 and 8813.*

As explained in https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/isArray, `instanceof Array` can have inconsistent behavior. To ensure that only `Array.isArray` is used, an ESLint plugin/rule is added to enforce this.
2018-07-09 13:17:41 +02:00

269 lines
7.5 KiB
JavaScript

/* Copyright 2012 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.
*/
import {
getVisibleElements, isValidRotation, NullL10n, scrollIntoView, watchScroll
} from './ui_utils';
import { PDFThumbnailView } from './pdf_thumbnail_view';
const THUMBNAIL_SCROLL_MARGIN = -19;
const THUMBNAIL_SELECTED_CLASS = 'selected';
/**
* @typedef {Object} PDFThumbnailViewerOptions
* @property {HTMLDivElement} container - The container for the thumbnail
* elements.
* @property {IPDFLinkService} linkService - The navigation/linking service.
* @property {PDFRenderingQueue} renderingQueue - The rendering queue object.
* @property {IL10n} l10n - Localization service.
*/
/**
* Viewer control to display thumbnails for pages in a PDF document.
*
* @implements {IRenderableView}
*/
class PDFThumbnailViewer {
/**
* @param {PDFThumbnailViewerOptions} options
*/
constructor({ container, linkService, renderingQueue, l10n = NullL10n, }) {
this.container = container;
this.linkService = linkService;
this.renderingQueue = renderingQueue;
this.l10n = l10n;
this.scroll = watchScroll(this.container, this._scrollUpdated.bind(this));
this._resetView();
}
/**
* @private
*/
_scrollUpdated() {
this.renderingQueue.renderHighestPriority();
}
getThumbnail(index) {
return this._thumbnails[index];
}
/**
* @private
*/
_getVisibleThumbs() {
return getVisibleElements(this.container, this._thumbnails);
}
scrollThumbnailIntoView(pageNumber) {
if (!this.pdfDocument) {
return;
}
const thumbnailView = this._thumbnails[pageNumber - 1];
if (!thumbnailView) {
console.error('scrollThumbnailIntoView: Invalid "pageNumber" parameter.');
return;
}
if (pageNumber !== this._currentPageNumber) {
const prevThumbnailView = this._thumbnails[this._currentPageNumber - 1];
// Remove the highlight from the previous thumbnail...
prevThumbnailView.div.classList.remove(THUMBNAIL_SELECTED_CLASS);
// ... and add the highlight to the new thumbnail.
thumbnailView.div.classList.add(THUMBNAIL_SELECTED_CLASS);
}
let visibleThumbs = this._getVisibleThumbs();
let numVisibleThumbs = visibleThumbs.views.length;
// If the thumbnail isn't currently visible, scroll it into view.
if (numVisibleThumbs > 0) {
let first = visibleThumbs.first.id;
// Account for only one thumbnail being visible.
let last = (numVisibleThumbs > 1 ? visibleThumbs.last.id : first);
let shouldScroll = false;
if (pageNumber <= first || pageNumber >= last) {
shouldScroll = true;
} else {
visibleThumbs.views.some(function(view) {
if (view.id !== pageNumber) {
return false;
}
shouldScroll = view.percent < 100;
return true;
});
}
if (shouldScroll) {
scrollIntoView(thumbnailView.div, { top: THUMBNAIL_SCROLL_MARGIN, });
}
}
this._currentPageNumber = pageNumber;
}
get pagesRotation() {
return this._pagesRotation;
}
set pagesRotation(rotation) {
if (!isValidRotation(rotation)) {
throw new Error('Invalid thumbnails rotation angle.');
}
if (!this.pdfDocument) {
return;
}
if (this._pagesRotation === rotation) {
return; // The rotation didn't change.
}
this._pagesRotation = rotation;
for (let i = 0, ii = this._thumbnails.length; i < ii; i++) {
this._thumbnails[i].update(rotation);
}
}
cleanup() {
PDFThumbnailView.cleanup();
}
/**
* @private
*/
_resetView() {
this._thumbnails = [];
this._currentPageNumber = 1;
this._pageLabels = null;
this._pagesRotation = 0;
this._pagesRequests = [];
// Remove the thumbnails from the DOM.
this.container.textContent = '';
}
setDocument(pdfDocument) {
if (this.pdfDocument) {
this._cancelRendering();
this._resetView();
}
this.pdfDocument = pdfDocument;
if (!pdfDocument) {
return;
}
pdfDocument.getPage(1).then((firstPage) => {
let pagesCount = pdfDocument.numPages;
let viewport = firstPage.getViewport(1.0);
for (let pageNum = 1; pageNum <= pagesCount; ++pageNum) {
let thumbnail = new PDFThumbnailView({
container: this.container,
id: pageNum,
defaultViewport: viewport.clone(),
linkService: this.linkService,
renderingQueue: this.renderingQueue,
disableCanvasToImageConversion: false,
l10n: this.l10n,
});
this._thumbnails.push(thumbnail);
}
// Ensure that the current thumbnail is always highlighted on load.
const thumbnailView = this._thumbnails[this._currentPageNumber - 1];
thumbnailView.div.classList.add(THUMBNAIL_SELECTED_CLASS);
}).catch((reason) => {
console.error('Unable to initialize thumbnail viewer', reason);
});
}
/**
* @private
*/
_cancelRendering() {
for (let i = 0, ii = this._thumbnails.length; i < ii; i++) {
if (this._thumbnails[i]) {
this._thumbnails[i].cancelRendering();
}
}
}
/**
* @param {Array|null} labels
*/
setPageLabels(labels) {
if (!this.pdfDocument) {
return;
}
if (!labels) {
this._pageLabels = null;
} else if (!(Array.isArray(labels) &&
this.pdfDocument.numPages === labels.length)) {
this._pageLabels = null;
console.error('PDFThumbnailViewer_setPageLabels: Invalid page labels.');
} else {
this._pageLabels = labels;
}
// Update all the `PDFThumbnailView` instances.
for (let i = 0, ii = this._thumbnails.length; i < ii; i++) {
let label = this._pageLabels && this._pageLabels[i];
this._thumbnails[i].setPageLabel(label);
}
}
/**
* @param {PDFThumbnailView} thumbView
* @returns {PDFPage}
* @private
*/
_ensurePdfPageLoaded(thumbView) {
if (thumbView.pdfPage) {
return Promise.resolve(thumbView.pdfPage);
}
let pageNumber = thumbView.id;
if (this._pagesRequests[pageNumber]) {
return this._pagesRequests[pageNumber];
}
let promise = this.pdfDocument.getPage(pageNumber).then((pdfPage) => {
thumbView.setPdfPage(pdfPage);
this._pagesRequests[pageNumber] = null;
return pdfPage;
}).catch((reason) => {
console.error('Unable to get page for thumb view', reason);
// Page error -- there is nothing can be done.
this._pagesRequests[pageNumber] = null;
});
this._pagesRequests[pageNumber] = promise;
return promise;
}
forceRendering() {
let visibleThumbs = this._getVisibleThumbs();
let thumbView = this.renderingQueue.getHighestPriority(visibleThumbs,
this._thumbnails,
this.scroll.down);
if (thumbView) {
this._ensurePdfPageLoaded(thumbView).then(() => {
this.renderingQueue.renderView(thumbView);
});
return true;
}
return false;
}
}
export {
PDFThumbnailViewer,
};