pdfjs-dist/lib/web/pdf_thumbnail_viewer.js

/* Copyright 2017 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.
 */
'use strict';
var uiUtils = require('./ui_utils.js');
var pdfThumbnailView = require('./pdf_thumbnail_view.js');
var watchScroll = uiUtils.watchScroll;
var getVisibleElements = uiUtils.getVisibleElements;
var scrollIntoView = uiUtils.scrollIntoView;
var PDFThumbnailView = pdfThumbnailView.PDFThumbnailView;
var THUMBNAIL_SCROLL_MARGIN = -19;
var PDFThumbnailViewer = function PDFThumbnailViewerClosure() {
 function PDFThumbnailViewer(options) {
  this.container = options.container;
  this.renderingQueue = options.renderingQueue;
  this.linkService = options.linkService;
  this.scroll = watchScroll(this.container, this._scrollUpdated.bind(this));
  this._resetView();
 }
 PDFThumbnailViewer.prototype = {
  _scrollUpdated: function PDFThumbnailViewer_scrollUpdated() {
   this.renderingQueue.renderHighestPriority();
  },
  getThumbnail: function PDFThumbnailViewer_getThumbnail(index) {
   return this.thumbnails[index];
  },
  _getVisibleThumbs: function PDFThumbnailViewer_getVisibleThumbs() {
   return getVisibleElements(this.container, this.thumbnails);
  },
  scrollThumbnailIntoView: function PDFThumbnailViewer_scrollThumbnailIntoView(page) {
   var selected = document.querySelector('.thumbnail.selected');
   if (selected) {
    selected.classList.remove('selected');
   }
   var thumbnail = document.querySelector('div.thumbnail[data-page-number="' + page + '"]');
   if (thumbnail) {
    thumbnail.classList.add('selected');
   }
   var visibleThumbs = this._getVisibleThumbs();
   var numVisibleThumbs = visibleThumbs.views.length;
   if (numVisibleThumbs > 0) {
    var first = visibleThumbs.first.id;
    var last = numVisibleThumbs > 1 ? visibleThumbs.last.id : first;
    if (page <= first || page >= last) {
     scrollIntoView(thumbnail, { top: THUMBNAIL_SCROLL_MARGIN });
    }
   }
  },
  get pagesRotation() {
   return this._pagesRotation;
  },
  set pagesRotation(rotation) {
   this._pagesRotation = rotation;
   for (var i = 0, l = this.thumbnails.length; i < l; i++) {
    var thumb = this.thumbnails[i];
    thumb.update(rotation);
   }
  },
  cleanup: function PDFThumbnailViewer_cleanup() {
   var tempCanvas = PDFThumbnailView.tempImageCache;
   if (tempCanvas) {
    tempCanvas.width = 0;
    tempCanvas.height = 0;
   }
   PDFThumbnailView.tempImageCache = null;
  },
  _resetView: function PDFThumbnailViewer_resetView() {
   this.thumbnails = [];
   this._pageLabels = null;
   this._pagesRotation = 0;
   this._pagesRequests = [];
   this.container.textContent = '';
  },
  setDocument: function PDFThumbnailViewer_setDocument(pdfDocument) {
   if (this.pdfDocument) {
    this._cancelRendering();
    this._resetView();
   }
   this.pdfDocument = pdfDocument;
   if (!pdfDocument) {
    return Promise.resolve();
   }
   return pdfDocument.getPage(1).then(function (firstPage) {
    var pagesCount = pdfDocument.numPages;
    var viewport = firstPage.getViewport(1.0);
    for (var pageNum = 1; pageNum <= pagesCount; ++pageNum) {
     var thumbnail = new PDFThumbnailView({
      container: this.container,
      id: pageNum,
      defaultViewport: viewport.clone(),
      linkService: this.linkService,
      renderingQueue: this.renderingQueue,
      disableCanvasToImageConversion: false
     });
     this.thumbnails.push(thumbnail);
    }
   }.bind(this));
  },
  _cancelRendering: function PDFThumbnailViewer_cancelRendering() {
   for (var i = 0, ii = this.thumbnails.length; i < ii; i++) {
    if (this.thumbnails[i]) {
     this.thumbnails[i].cancelRendering();
    }
   }
  },
  setPageLabels: function PDFThumbnailViewer_setPageLabels(labels) {
   if (!this.pdfDocument) {
    return;
   }
   if (!labels) {
    this._pageLabels = null;
   } else if (!(labels instanceof Array && this.pdfDocument.numPages === labels.length)) {
    this._pageLabels = null;
    console.error('PDFThumbnailViewer_setPageLabels: Invalid page labels.');
   } else {
    this._pageLabels = labels;
   }
   for (var i = 0, ii = this.thumbnails.length; i < ii; i++) {
    var thumbnailView = this.thumbnails[i];
    var label = this._pageLabels && this._pageLabels[i];
    thumbnailView.setPageLabel(label);
   }
  },
  _ensurePdfPageLoaded: function PDFThumbnailViewer_ensurePdfPageLoaded(thumbView) {
   if (thumbView.pdfPage) {
    return Promise.resolve(thumbView.pdfPage);
   }
   var pageNumber = thumbView.id;
   if (this._pagesRequests[pageNumber]) {
    return this._pagesRequests[pageNumber];
   }
   var promise = this.pdfDocument.getPage(pageNumber).then(function (pdfPage) {
    thumbView.setPdfPage(pdfPage);
    this._pagesRequests[pageNumber] = null;
    return pdfPage;
   }.bind(this));
   this._pagesRequests[pageNumber] = promise;
   return promise;
  },
  forceRendering: function () {
   var visibleThumbs = this._getVisibleThumbs();
   var thumbView = this.renderingQueue.getHighestPriority(visibleThumbs, this.thumbnails, this.scroll.down);
   if (thumbView) {
    this._ensurePdfPageLoaded(thumbView).then(function () {
     this.renderingQueue.renderView(thumbView);
    }.bind(this));
    return true;
   }
   return false;
  }
 };
 return PDFThumbnailViewer;
}();
exports.PDFThumbnailViewer = PDFThumbnailViewer;