pdf.js/web/pdf_viewer.js
Ryan Hendrickson 3d83c646c6 Add spread modes to web viewer
This builds on the scrolling mode work to add three buttons for joining
page spreads together: one for the default view, with no page spreads,
and two for spreads starting on odd-numbered or even-numbered pages.
2018-05-14 23:10:32 -04:00

122 lines
3.7 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.
*/
import { BaseViewer, ScrollMode, SpreadMode } from './base_viewer';
import { getVisibleElements, scrollIntoView } from './ui_utils';
import { shadow } from 'pdfjs-lib';
class PDFViewer extends BaseViewer {
get _setDocumentViewerElement() {
return shadow(this, '_setDocumentViewerElement', this.viewer);
}
_scrollIntoView({ pageDiv, pageSpot = null, }) {
if (!pageSpot) {
const left = pageDiv.offsetLeft + pageDiv.clientLeft;
const right = left + pageDiv.clientWidth;
const { scrollLeft, clientWidth, } = this.container;
if (this.scrollMode === ScrollMode.HORIZONTAL ||
left < scrollLeft || right > scrollLeft + clientWidth) {
pageSpot = { left: 0, top: 0, };
}
}
scrollIntoView(pageDiv, pageSpot);
}
_getVisiblePages() {
if (!this.isInPresentationMode) {
return getVisibleElements(this.container, this._pages, true,
this.scrollMode === ScrollMode.HORIZONTAL);
}
// The algorithm in getVisibleElements doesn't work in all browsers and
// configurations when presentation mode is active.
let currentPage = this._pages[this._currentPageNumber - 1];
let visible = [{ id: currentPage.id, view: currentPage, }];
return { first: currentPage, last: currentPage, views: visible, };
}
update() {
let visible = this._getVisiblePages();
let visiblePages = visible.views, numVisiblePages = visiblePages.length;
if (numVisiblePages === 0) {
return;
}
this._resizeBuffer(numVisiblePages, visiblePages);
this.renderingQueue.renderHighestPriority(visible);
let currentId = this._currentPageNumber;
let stillFullyVisible = false;
for (let i = 0; i < numVisiblePages; ++i) {
let page = visiblePages[i];
if (page.percent < 100) {
break;
}
if (page.id === currentId) {
stillFullyVisible = true;
break;
}
}
if (!stillFullyVisible) {
currentId = visiblePages[0].id;
}
if (!this.isInPresentationMode) {
this._setCurrentPageNumber(currentId);
}
this._updateLocation(visible.first);
this.eventBus.dispatch('updateviewarea', {
source: this,
location: this._location,
});
}
_regroupSpreads() {
const container = this._setDocumentViewerElement, pages = this._pages;
while (container.firstChild) {
container.firstChild.remove();
}
if (this.spreadMode === SpreadMode.NONE) {
for (let i = 0, iMax = pages.length; i < iMax; ++i) {
container.appendChild(pages[i].div);
}
} else {
const parity = this.spreadMode - 1;
let spread = null;
for (let i = 0, iMax = pages.length; i < iMax; ++i) {
if (spread === null) {
spread = document.createElement('div');
spread.className = 'spread';
container.appendChild(spread);
} else if (i % 2 === parity) {
spread = spread.cloneNode(false);
container.appendChild(spread);
}
spread.appendChild(pages[i].div);
}
}
this.scrollPageIntoView({ pageNumber: this._currentPageNumber, });
this.update();
}
}
export {
PDFViewer,
};