pdfjs-dist/web/pdf_viewer.js

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* 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.
 */
/*jshint globalstrict: false */
/* globals PDFJS, PDFViewer */

// Initializing PDFJS global object (if still undefined)
if (typeof PDFJS === 'undefined') {
  (typeof window !== 'undefined' ? window : this).PDFJS = {};
}

(function pdfViewerWrapper() {
  'use strict';


var CSS_UNITS = 96.0 / 72.0;
var DEFAULT_SCALE = 'auto';
var UNKNOWN_SCALE = 0;
var MAX_AUTO_SCALE = 1.25;
var SCROLLBAR_PADDING = 40;
var VERTICAL_PADDING = 5;
var DEFAULT_CACHE_SIZE = 10;

// optimised CSS custom property getter/setter
var CustomStyle = (function CustomStyleClosure() {

  // As noted on: http://www.zachstronaut.com/posts/2009/02/17/
  //              animate-css-transforms-firefox-webkit.html
  // in some versions of IE9 it is critical that ms appear in this list
  // before Moz
  var prefixes = ['ms', 'Moz', 'Webkit', 'O'];
  var _cache = {};

  function CustomStyle() {}

  CustomStyle.getProp = function get(propName, element) {
    // check cache only when no element is given
    if (arguments.length === 1 && typeof _cache[propName] === 'string') {
      return _cache[propName];
    }

    element = element || document.documentElement;
    var style = element.style, prefixed, uPropName;

    // test standard property first
    if (typeof style[propName] === 'string') {
      return (_cache[propName] = propName);
    }

    // capitalize
    uPropName = propName.charAt(0).toUpperCase() + propName.slice(1);

    // test vendor specific properties
    for (var i = 0, l = prefixes.length; i < l; i++) {
      prefixed = prefixes[i] + uPropName;
      if (typeof style[prefixed] === 'string') {
        return (_cache[propName] = prefixed);
      }
    }

    //if all fails then set to undefined
    return (_cache[propName] = 'undefined');
  };

  CustomStyle.setProp = function set(propName, element, str) {
    var prop = this.getProp(propName);
    if (prop !== 'undefined') {
      element.style[prop] = str;
    }
  };

  return CustomStyle;
})();

function getFileName(url) {
  var anchor = url.indexOf('#');
  var query = url.indexOf('?');
  var end = Math.min(
    anchor > 0 ? anchor : url.length,
    query > 0 ? query : url.length);
  return url.substring(url.lastIndexOf('/', end) + 1, end);
}

/**
 * Returns scale factor for the canvas. It makes sense for the HiDPI displays.
 * @return {Object} The object with horizontal (sx) and vertical (sy)
                    scales. The scaled property is set to false if scaling is
                    not required, true otherwise.
 */
function getOutputScale(ctx) {
  var devicePixelRatio = window.devicePixelRatio || 1;
  var backingStoreRatio = ctx.webkitBackingStorePixelRatio ||
                          ctx.mozBackingStorePixelRatio ||
                          ctx.msBackingStorePixelRatio ||
                          ctx.oBackingStorePixelRatio ||
                          ctx.backingStorePixelRatio || 1;
  var pixelRatio = devicePixelRatio / backingStoreRatio;
  return {
    sx: pixelRatio,
    sy: pixelRatio,
    scaled: pixelRatio !== 1
  };
}

/**
 * Scrolls specified element into view of its parent.
 * element {Object} The element to be visible.
 * spot {Object} An object with optional top and left properties,
 *               specifying the offset from the top left edge.
 */
function scrollIntoView(element, spot) {
  // Assuming offsetParent is available (it's not available when viewer is in
  // hidden iframe or object). We have to scroll: if the offsetParent is not set
  // producing the error. See also animationStartedClosure.
  var parent = element.offsetParent;
  var offsetY = element.offsetTop + element.clientTop;
  var offsetX = element.offsetLeft + element.clientLeft;
  if (!parent) {
    console.error('offsetParent is not set -- cannot scroll');
    return;
  }
  while (parent.clientHeight === parent.scrollHeight) {
    if (parent.dataset._scaleY) {
      offsetY /= parent.dataset._scaleY;
      offsetX /= parent.dataset._scaleX;
    }
    offsetY += parent.offsetTop;
    offsetX += parent.offsetLeft;
    parent = parent.offsetParent;
    if (!parent) {
      return; // no need to scroll
    }
  }
  if (spot) {
    if (spot.top !== undefined) {
      offsetY += spot.top;
    }
    if (spot.left !== undefined) {
      offsetX += spot.left;
      parent.scrollLeft = offsetX;
    }
  }
  parent.scrollTop = offsetY;
}

/**
 * Helper function to start monitoring the scroll event and converting them into
 * PDF.js friendly one: with scroll debounce and scroll direction.
 */
function watchScroll(viewAreaElement, callback) {
  var debounceScroll = function debounceScroll(evt) {
    if (rAF) {
      return;
    }
    // schedule an invocation of scroll for next animation frame.
    rAF = window.requestAnimationFrame(function viewAreaElementScrolled() {
      rAF = null;

      var currentY = viewAreaElement.scrollTop;
      var lastY = state.lastY;
      if (currentY > lastY) {
        state.down = true;
      } else if (currentY < lastY) {
        state.down = false;
      }
      state.lastY = currentY;
      // else do nothing and use previous value
      callback(state);
    });
  };

  var state = {
    down: true,
    lastY: viewAreaElement.scrollTop,
    _eventHandler: debounceScroll
  };

  var rAF = null;
  viewAreaElement.addEventListener('scroll', debounceScroll, true);
  return state;
}

/**
 * Generic helper to find out what elements are visible within a scroll pane.
 */
function getVisibleElements(scrollEl, views, sortByVisibility) {
  var top = scrollEl.scrollTop, bottom = top + scrollEl.clientHeight;
  var left = scrollEl.scrollLeft, right = left + scrollEl.clientWidth;

  var visible = [], view;
  var currentHeight, viewHeight, hiddenHeight, percentHeight;
  var currentWidth, viewWidth;
  for (var i = 0, ii = views.length; i < ii; ++i) {
    view = views[i];
    currentHeight = view.el.offsetTop + view.el.clientTop;
    viewHeight = view.el.clientHeight;
    if ((currentHeight + viewHeight) < top) {
      continue;
    }
    if (currentHeight > bottom) {
      break;
    }
    currentWidth = view.el.offsetLeft + view.el.clientLeft;
    viewWidth = view.el.clientWidth;
    if ((currentWidth + viewWidth) < left || currentWidth > right) {
      continue;
    }
    hiddenHeight = Math.max(0, top - currentHeight) +
      Math.max(0, currentHeight + viewHeight - bottom);
    percentHeight = ((viewHeight - hiddenHeight) * 100 / viewHeight) | 0;

    visible.push({ id: view.id, x: currentWidth, y: currentHeight,
      view: view, percent: percentHeight });
  }

  var first = visible[0];
  var last = visible[visible.length - 1];

  if (sortByVisibility) {
    visible.sort(function(a, b) {
      var pc = a.percent - b.percent;
      if (Math.abs(pc) > 0.001) {
        return -pc;
      }
      return a.id - b.id; // ensure stability
    });
  }
  return {first: first, last: last, views: visible};
}

/**
 * Event handler to suppress context menu.
 */
function noContextMenuHandler(e) {
  e.preventDefault();
}

/**
 * Returns the filename or guessed filename from the url (see issue 3455).
 * url {String} The original PDF location.
 * @return {String} Guessed PDF file name.
 */
function getPDFFileNameFromURL(url) {
  var reURI = /^(?:([^:]+:)?\/\/[^\/]+)?([^?#]*)(\?[^#]*)?(#.*)?$/;
  //            SCHEME      HOST         1.PATH  2.QUERY   3.REF
  // Pattern to get last matching NAME.pdf
  var reFilename = /[^\/?#=]+\.pdf\b(?!.*\.pdf\b)/i;
  var splitURI = reURI.exec(url);
  var suggestedFilename = reFilename.exec(splitURI[1]) ||
                           reFilename.exec(splitURI[2]) ||
                           reFilename.exec(splitURI[3]);
  if (suggestedFilename) {
    suggestedFilename = suggestedFilename[0];
    if (suggestedFilename.indexOf('%') !== -1) {
      // URL-encoded %2Fpath%2Fto%2Ffile.pdf should be file.pdf
      try {
        suggestedFilename =
          reFilename.exec(decodeURIComponent(suggestedFilename))[0];
      } catch(e) { // Possible (extremely rare) errors:
        // URIError "Malformed URI", e.g. for "%AA.pdf"
        // TypeError "null has no properties", e.g. for "%2F.pdf"
      }
    }
  }
  return suggestedFilename || 'document.pdf';
}

var ProgressBar = (function ProgressBarClosure() {

  function clamp(v, min, max) {
    return Math.min(Math.max(v, min), max);
  }

  function ProgressBar(id, opts) {

    // Fetch the sub-elements for later.
    this.div = document.querySelector(id + ' .progress');

    // Get the loading bar element, so it can be resized to fit the viewer.
    this.bar = this.div.parentNode;

    // Get options, with sensible defaults.
    this.height = opts.height || 100;
    this.width = opts.width || 100;
    this.units = opts.units || '%';

    // Initialize heights.
    this.div.style.height = this.height + this.units;
    this.percent = 0;
  }

  ProgressBar.prototype = {

    updateBar: function ProgressBar_updateBar() {
      if (this._indeterminate) {
        this.div.classList.add('indeterminate');
        this.div.style.width = this.width + this.units;
        return;
      }

      this.div.classList.remove('indeterminate');
      var progressSize = this.width * this._percent / 100;
      this.div.style.width = progressSize + this.units;
    },

    get percent() {
      return this._percent;
    },

    set percent(val) {
      this._indeterminate = isNaN(val);
      this._percent = clamp(val, 0, 100);
      this.updateBar();
    },

    setWidth: function ProgressBar_setWidth(viewer) {
      if (viewer) {
        var container = viewer.parentNode;
        var scrollbarWidth = container.offsetWidth - viewer.offsetWidth;
        if (scrollbarWidth > 0) {
          this.bar.setAttribute('style', 'width: calc(100% - ' +
                                         scrollbarWidth + 'px);');
        }
      }
    },

    hide: function ProgressBar_hide() {
      this.bar.classList.add('hidden');
      this.bar.removeAttribute('style');
    }
  };

  return ProgressBar;
})();

var Cache = function cacheCache(size) {
  var data = [];
  this.push = function cachePush(view) {
    var i = data.indexOf(view);
    if (i >= 0) {
      data.splice(i, 1);
    }
    data.push(view);
    if (data.length > size) {
      data.shift().destroy();
    }
  };
  this.resize = function (newSize) {
    size = newSize;
    while (data.length > size) {
      data.shift().destroy();
    }
  };
};



var PresentationModeState = {
  UNKNOWN: 0,
  NORMAL: 1,
  CHANGING: 2,
  FULLSCREEN: 3,
};

var IGNORE_CURRENT_POSITION_ON_ZOOM = false;


var CLEANUP_TIMEOUT = 30000;

var RenderingStates = {
  INITIAL: 0,
  RUNNING: 1,
  PAUSED: 2,
  FINISHED: 3
};

/**
 * Controls rendering of the views for pages and thumbnails.
 * @class
 */
var PDFRenderingQueue = (function PDFRenderingQueueClosure() {
  /**
   * @constructs
   */
  function PDFRenderingQueue() {
    this.pdfViewer = null;
    this.pdfThumbnailViewer = null;
    this.onIdle = null;

    this.highestPriorityPage = null;
    this.idleTimeout = null;
    this.printing = false;
    this.isThumbnailViewEnabled = false;
  }

  PDFRenderingQueue.prototype = /** @lends PDFRenderingQueue.prototype */ {
    /**
     * @param {PDFViewer} pdfViewer
     */
    setViewer: function PDFRenderingQueue_setViewer(pdfViewer) {
      this.pdfViewer = pdfViewer;
    },

    /**
     * @param {PDFThumbnailViewer} pdfThumbnailViewer
     */
    setThumbnailViewer:
        function PDFRenderingQueue_setThumbnailViewer(pdfThumbnailViewer) {
      this.pdfThumbnailViewer = pdfThumbnailViewer;
    },

    /**
     * @param {IRenderableView} view
     * @returns {boolean}
     */
    isHighestPriority: function PDFRenderingQueue_isHighestPriority(view) {
      return this.highestPriorityPage === view.renderingId;
    },

    renderHighestPriority: function
        PDFRenderingQueue_renderHighestPriority(currentlyVisiblePages) {
      if (this.idleTimeout) {
        clearTimeout(this.idleTimeout);
        this.idleTimeout = null;
      }

      // Pages have a higher priority than thumbnails, so check them first.
      if (this.pdfViewer.forceRendering(currentlyVisiblePages)) {
        return;
      }
      // No pages needed rendering so check thumbnails.
      if (this.pdfThumbnailViewer && this.isThumbnailViewEnabled) {
        if (this.pdfThumbnailViewer.forceRendering()) {
          return;
        }
      }

      if (this.printing) {
        // If printing is currently ongoing do not reschedule cleanup.
        return;
      }

      if (this.onIdle) {
        this.idleTimeout = setTimeout(this.onIdle.bind(this), CLEANUP_TIMEOUT);
      }
    },

    getHighestPriority: function
        PDFRenderingQueue_getHighestPriority(visible, views, scrolledDown) {
      // The state has changed figure out which page has the highest priority to
      // render next (if any).
      // Priority:
      // 1 visible pages
      // 2 if last scrolled down page after the visible pages
      // 2 if last scrolled up page before the visible pages
      var visibleViews = visible.views;

      var numVisible = visibleViews.length;
      if (numVisible === 0) {
        return false;
      }
      for (var i = 0; i < numVisible; ++i) {
        var view = visibleViews[i].view;
        if (!this.isViewFinished(view)) {
          return view;
        }
      }

      // All the visible views have rendered, try to render next/previous pages.
      if (scrolledDown) {
        var nextPageIndex = visible.last.id;
        // ID's start at 1 so no need to add 1.
        if (views[nextPageIndex] &&
            !this.isViewFinished(views[nextPageIndex])) {
          return views[nextPageIndex];
        }
      } else {
        var previousPageIndex = visible.first.id - 2;
        if (views[previousPageIndex] &&
          !this.isViewFinished(views[previousPageIndex])) {
          return views[previousPageIndex];
        }
      }
      // Everything that needs to be rendered has been.
      return null;
    },

    /**
     * @param {IRenderableView} view
     * @returns {boolean}
     */
    isViewFinished: function PDFRenderingQueue_isViewFinished(view) {
      return view.renderingState === RenderingStates.FINISHED;
    },

    /**
     * Render a page or thumbnail view. This calls the appropriate function
     * based on the views state. If the view is already rendered it will return
     * false.
     * @param {IRenderableView} view
     */
    renderView: function PDFRenderingQueue_renderView(view) {
      var state = view.renderingState;
      switch (state) {
        case RenderingStates.FINISHED:
          return false;
        case RenderingStates.PAUSED:
          this.highestPriorityPage = view.renderingId;
          view.resume();
          break;
        case RenderingStates.RUNNING:
          this.highestPriorityPage = view.renderingId;
          break;
        case RenderingStates.INITIAL:
          this.highestPriorityPage = view.renderingId;
          view.draw(this.renderHighestPriority.bind(this));
          break;
      }
      return true;
    },
  };

  return PDFRenderingQueue;
})();


/**
 * @constructor
 * @param {HTMLDivElement} container - The viewer element.
 * @param {number} id - The page unique ID (normally its number).
 * @param {number} scale - The page scale display.
 * @param {PageViewport} defaultViewport - The page viewport.
 * @param {IPDFLinkService} linkService - The navigation/linking service.
 * @param {PDFRenderingQueue} renderingQueue - The rendering queue object.
 * @param {Cache} cache - The page cache.
 * @param {PDFPageSource} pageSource
 * @param {PDFViewer} viewer
 *
 * @implements {IRenderableView}
 */
var PageView = function pageView(container, id, scale, defaultViewport,
                                 linkService, renderingQueue, cache,
                                 pageSource, viewer) {
  this.id = id;
  this.renderingId = 'page' + id;

  this.rotation = 0;
  this.scale = scale || 1.0;
  this.viewport = defaultViewport;
  this.pdfPageRotate = defaultViewport.rotation;
  this.hasRestrictedScaling = false;

  this.linkService = linkService;
  this.renderingQueue = renderingQueue;
  this.cache = cache;
  this.pageSource = pageSource;
  this.viewer = viewer;

  this.renderingState = RenderingStates.INITIAL;
  this.resume = null;

  this.textLayer = null;

  this.zoomLayer = null;

  this.annotationLayer = null;

  var anchor = document.createElement('a');
  anchor.name = '' + this.id;

  var div = this.el = document.createElement('div');
  div.id = 'pageContainer' + this.id;
  div.className = 'page';
  div.style.width = Math.floor(this.viewport.width) + 'px';
  div.style.height = Math.floor(this.viewport.height) + 'px';

  container.appendChild(anchor);
  container.appendChild(div);

  this.setPdfPage = function pageViewSetPdfPage(pdfPage) {
    this.pdfPage = pdfPage;
    this.pdfPageRotate = pdfPage.rotate;
    var totalRotation = (this.rotation + this.pdfPageRotate) % 360;
    this.viewport = pdfPage.getViewport(this.scale * CSS_UNITS, totalRotation);
    this.stats = pdfPage.stats;
    this.reset();
  };

  this.destroy = function pageViewDestroy() {
    this.zoomLayer = null;
    this.reset();
    if (this.pdfPage) {
      this.pdfPage.destroy();
    }
  };

  this.reset = function pageViewReset(keepAnnotations) {
    if (this.renderTask) {
      this.renderTask.cancel();
    }
    this.resume = null;
    this.renderingState = RenderingStates.INITIAL;

    div.style.width = Math.floor(this.viewport.width) + 'px';
    div.style.height = Math.floor(this.viewport.height) + 'px';

    var childNodes = div.childNodes;
    for (var i = div.childNodes.length - 1; i >= 0; i--) {
      var node = childNodes[i];
      if ((this.zoomLayer && this.zoomLayer === node) ||
          (keepAnnotations && this.annotationLayer === node)) {
        continue;
      }
      div.removeChild(node);
    }
    div.removeAttribute('data-loaded');

    if (keepAnnotations) {
      if (this.annotationLayer) {
        // Hide annotationLayer until all elements are resized
        // so they are not displayed on the already-resized page
        this.annotationLayer.setAttribute('hidden', 'true');
      }
    } else {
      this.annotationLayer = null;
    }

    if (this.canvas) {
      // Zeroing the width and height causes Firefox to release graphics
      // resources immediately, which can greatly reduce memory consumption.
      this.canvas.width = 0;
      this.canvas.height = 0;
      delete this.canvas;
    }

    this.loadingIconDiv = document.createElement('div');
    this.loadingIconDiv.className = 'loadingIcon';
    div.appendChild(this.loadingIconDiv);
  };

  this.update = function pageViewUpdate(scale, rotation) {
    this.scale = scale || this.scale;

    if (typeof rotation !== 'undefined') {
      this.rotation = rotation;
    }

    var totalRotation = (this.rotation + this.pdfPageRotate) % 360;
    this.viewport = this.viewport.clone({
      scale: this.scale * CSS_UNITS,
      rotation: totalRotation
    });

    var isScalingRestricted = false;
    if (this.canvas && PDFJS.maxCanvasPixels > 0) {
      var ctx = this.canvas.getContext('2d');
      var outputScale = getOutputScale(ctx);
      var pixelsInViewport = this.viewport.width * this.viewport.height;
      var maxScale = Math.sqrt(PDFJS.maxCanvasPixels / pixelsInViewport);
      if (((Math.floor(this.viewport.width) * outputScale.sx) | 0) *
          ((Math.floor(this.viewport.height) * outputScale.sy) | 0) >
          PDFJS.maxCanvasPixels) {
        isScalingRestricted = true;
      }
    }

    if (this.canvas &&
        (PDFJS.useOnlyCssZoom ||
          (this.hasRestrictedScaling && isScalingRestricted))) {
      this.cssTransform(this.canvas, true);
      return;
    } else if (this.canvas && !this.zoomLayer) {
      this.zoomLayer = this.canvas.parentNode;
      this.zoomLayer.style.position = 'absolute';
    }
    if (this.zoomLayer) {
      this.cssTransform(this.zoomLayer.firstChild);
    }
    this.reset(true);
  };

  this.cssTransform = function pageCssTransform(canvas, redrawAnnotations) {
    // Scale canvas, canvas wrapper, and page container.
    var width = this.viewport.width;
    var height = this.viewport.height;
    canvas.style.width = canvas.parentNode.style.width = div.style.width =
        Math.floor(width) + 'px';
    canvas.style.height = canvas.parentNode.style.height = div.style.height =
        Math.floor(height) + 'px';
    // The canvas may have been originally rotated, so rotate relative to that.
    var relativeRotation = this.viewport.rotation - canvas._viewport.rotation;
    var absRotation = Math.abs(relativeRotation);
    var scaleX = 1, scaleY = 1;
    if (absRotation === 90 || absRotation === 270) {
      // Scale x and y because of the rotation.
      scaleX = height / width;
      scaleY = width / height;
    }
    var cssTransform = 'rotate(' + relativeRotation + 'deg) ' +
                       'scale(' + scaleX + ',' + scaleY + ')';
    CustomStyle.setProp('transform', canvas, cssTransform);

    if (this.textLayer) {
      // Rotating the text layer is more complicated since the divs inside the
      // the text layer are rotated.
      // TODO: This could probably be simplified by drawing the text layer in
      // one orientation then rotating overall.
      var textLayerViewport = this.textLayer.viewport;
      var textRelativeRotation = this.viewport.rotation -
                                 textLayerViewport.rotation;
      var textAbsRotation = Math.abs(textRelativeRotation);
      var scale = width / textLayerViewport.width;
      if (textAbsRotation === 90 || textAbsRotation === 270) {
        scale = width / textLayerViewport.height;
      }
      var textLayerDiv = this.textLayer.textLayerDiv;
      var transX, transY;
      switch (textAbsRotation) {
        case 0:
          transX = transY = 0;
          break;
        case 90:
          transX = 0;
          transY = '-' + textLayerDiv.style.height;
          break;
        case 180:
          transX = '-' + textLayerDiv.style.width;
          transY = '-' + textLayerDiv.style.height;
          break;
        case 270:
          transX = '-' + textLayerDiv.style.width;
          transY = 0;
          break;
        default:
          console.error('Bad rotation value.');
          break;
      }
      CustomStyle.setProp('transform', textLayerDiv,
                          'rotate(' + textAbsRotation + 'deg) ' +
                            'scale(' + scale + ', ' + scale + ') ' +
                            'translate(' + transX + ', ' + transY + ')');
      CustomStyle.setProp('transformOrigin', textLayerDiv, '0% 0%');
    }

    if (redrawAnnotations && this.annotationLayer) {
      setupAnnotations(div, this.pdfPage, this.viewport);
    }
  };

  Object.defineProperty(this, 'width', {
    get: function PageView_getWidth() {
      return this.viewport.width;
    },
    enumerable: true
  });

  Object.defineProperty(this, 'height', {
    get: function PageView_getHeight() {
      return this.viewport.height;
    },
    enumerable: true
  });

  var self = this;

  function setupAnnotations(pageDiv, pdfPage, viewport) {

    function bindLink(link, dest) {
      link.href = linkService.getDestinationHash(dest);
      link.onclick = function pageViewSetupLinksOnclick() {
        if (dest) {
          linkService.navigateTo(dest);
        }
        return false;
      };
      if (dest) {
        link.className = 'internalLink';
      }
    }

    function bindNamedAction(link, action) {
      link.href = linkService.getAnchorUrl('');
      link.onclick = function pageViewSetupNamedActionOnClick() {
        linkService.executeNamedAction(action);
        return false;
      };
      link.className = 'internalLink';
    }

    pdfPage.getAnnotations().then(function(annotationsData) {
      viewport = viewport.clone({ dontFlip: true });
      var transform = viewport.transform;
      var transformStr = 'matrix(' + transform.join(',') + ')';
      var data, element, i, ii;

      if (self.annotationLayer) {
        // If an annotationLayer already exists, refresh its children's
        // transformation matrices
        for (i = 0, ii = annotationsData.length; i < ii; i++) {
          data = annotationsData[i];
          element = self.annotationLayer.querySelector(
            '[data-annotation-id="' + data.id + '"]');
          if (element) {
            CustomStyle.setProp('transform', element, transformStr);
          }
        }
        // See this.reset()
        self.annotationLayer.removeAttribute('hidden');
      } else {
        for (i = 0, ii = annotationsData.length; i < ii; i++) {
          data = annotationsData[i];
          if (!data || !data.hasHtml) {
            continue;
          }

          element = PDFJS.AnnotationUtils.getHtmlElement(data,
                                                         pdfPage.commonObjs);
          element.setAttribute('data-annotation-id', data.id);
          mozL10n.translate(element);

          var rect = data.rect;
          var view = pdfPage.view;
          rect = PDFJS.Util.normalizeRect([
            rect[0],
            view[3] - rect[1] + view[1],
            rect[2],
            view[3] - rect[3] + view[1]
          ]);
          element.style.left = rect[0] + 'px';
          element.style.top = rect[1] + 'px';
          element.style.position = 'absolute';

          CustomStyle.setProp('transform', element, transformStr);
          var transformOriginStr = -rect[0] + 'px ' + -rect[1] + 'px';
          CustomStyle.setProp('transformOrigin', element, transformOriginStr);

          if (data.subtype === 'Link' && !data.url) {
            var link = element.getElementsByTagName('a')[0];
            if (link) {
              if (data.action) {
                bindNamedAction(link, data.action);
              } else {
                bindLink(link, ('dest' in data) ? data.dest : null);
              }
            }
          }

          if (!self.annotationLayer) {
            var annotationLayerDiv = document.createElement('div');
            annotationLayerDiv.className = 'annotationLayer';
            pageDiv.appendChild(annotationLayerDiv);
            self.annotationLayer = annotationLayerDiv;
          }

          self.annotationLayer.appendChild(element);
        }
      }
    });
  }

  this.getPagePoint = function pageViewGetPagePoint(x, y) {
    return this.viewport.convertToPdfPoint(x, y);
  };

  this.draw = function pageviewDraw(callback) {
    var pdfPage = this.pdfPage;

    if (this.pagePdfPromise) {
      return;
    }
    if (!pdfPage) {
      var promise = this.pageSource.getPage();
      promise.then(function(pdfPage) {
        delete this.pagePdfPromise;
        this.setPdfPage(pdfPage);
        this.draw(callback);
      }.bind(this));
      this.pagePdfPromise = promise;
      return;
    }

    if (this.renderingState !== RenderingStates.INITIAL) {
      console.error('Must be in new state before drawing');
    }

    this.renderingState = RenderingStates.RUNNING;

    var viewport = this.viewport;
    // Wrap the canvas so if it has a css transform for highdpi the overflow
    // will be hidden in FF.
    var canvasWrapper = document.createElement('div');
    canvasWrapper.style.width = div.style.width;
    canvasWrapper.style.height = div.style.height;
    canvasWrapper.classList.add('canvasWrapper');

    var canvas = document.createElement('canvas');
    canvas.id = 'page' + this.id;
    canvasWrapper.appendChild(canvas);
    if (this.annotationLayer) {
      // annotationLayer needs to stay on top
      div.insertBefore(canvasWrapper, this.annotationLayer);
    } else {
      div.appendChild(canvasWrapper);
    }
    this.canvas = canvas;

    var ctx = canvas.getContext('2d');
    var outputScale = getOutputScale(ctx);

    if (PDFJS.useOnlyCssZoom) {
      var actualSizeViewport = viewport.clone({ scale: CSS_UNITS });
      // Use a scale that will make the canvas be the original intended size
      // of the page.
      outputScale.sx *= actualSizeViewport.width / viewport.width;
      outputScale.sy *= actualSizeViewport.height / viewport.height;
      outputScale.scaled = true;
    }

    if (PDFJS.maxCanvasPixels > 0) {
      var pixelsInViewport = viewport.width * viewport.height;
      var maxScale = Math.sqrt(PDFJS.maxCanvasPixels / pixelsInViewport);
      if (outputScale.sx > maxScale || outputScale.sy > maxScale) {
        outputScale.sx = maxScale;
        outputScale.sy = maxScale;
        outputScale.scaled = true;
        this.hasRestrictedScaling = true;
      } else {
        this.hasRestrictedScaling = false;
      }
    }

    canvas.width = (Math.floor(viewport.width) * outputScale.sx) | 0;
    canvas.height = (Math.floor(viewport.height) * outputScale.sy) | 0;
    canvas.style.width = Math.floor(viewport.width) + 'px';
    canvas.style.height = Math.floor(viewport.height) + 'px';
    // Add the viewport so it's known what it was originally drawn with.
    canvas._viewport = viewport;

    var textLayerDiv = null;
    var textLayer = null;
    if (!PDFJS.disableTextLayer) {
      textLayerDiv = document.createElement('div');
      textLayerDiv.className = 'textLayer';
      textLayerDiv.style.width = canvas.style.width;
      textLayerDiv.style.height = canvas.style.height;
      if (this.annotationLayer) {
        // annotationLayer needs to stay on top
        div.insertBefore(textLayerDiv, this.annotationLayer);
      } else {
        div.appendChild(textLayerDiv);
      }

      textLayer = this.viewer.createTextLayerBuilder(textLayerDiv, this.id - 1,
                                                     this.viewport);
    }
    this.textLayer = textLayer;

    // TODO(mack): use data attributes to store these
    ctx._scaleX = outputScale.sx;
    ctx._scaleY = outputScale.sy;
    if (outputScale.scaled) {
      ctx.scale(outputScale.sx, outputScale.sy);
    }

    // Rendering area

    var self = this;
    function pageViewDrawCallback(error) {
      // The renderTask may have been replaced by a new one, so only remove the
      // reference to the renderTask if it matches the one that is triggering
      // this callback.
      if (renderTask === self.renderTask) {
        self.renderTask = null;
      }

      if (error === 'cancelled') {
        return;
      }

      self.renderingState = RenderingStates.FINISHED;

      if (self.loadingIconDiv) {
        div.removeChild(self.loadingIconDiv);
        delete self.loadingIconDiv;
      }

      if (self.zoomLayer) {
        div.removeChild(self.zoomLayer);
        self.zoomLayer = null;
      }

      self.error = error;
      self.stats = pdfPage.stats;
      self.updateStats();
      if (self.onAfterDraw) {
        self.onAfterDraw();
      }

      var event = document.createEvent('CustomEvent');
      event.initCustomEvent('pagerender', true, true, {
        pageNumber: pdfPage.pageNumber
      });
      div.dispatchEvent(event);

      callback();
    }

    var renderContext = {
      canvasContext: ctx,
      viewport: this.viewport,
      // intent: 'default', // === 'display'
      continueCallback: function pdfViewcContinueCallback(cont) {
        if (!self.renderingQueue.isHighestPriority(self)) {
          self.renderingState = RenderingStates.PAUSED;
          self.resume = function resumeCallback() {
            self.renderingState = RenderingStates.RUNNING;
            cont();
          };
          return;
        }
        cont();
      }
    };
    var renderTask = this.renderTask = this.pdfPage.render(renderContext);

    this.renderTask.promise.then(
      function pdfPageRenderCallback() {
        pageViewDrawCallback(null);
        if (textLayer) {
          self.pdfPage.getTextContent().then(
            function textContentResolved(textContent) {
              textLayer.setTextContent(textContent);
            }
          );
        }
      },
      function pdfPageRenderError(error) {
        pageViewDrawCallback(error);
      }
    );

    setupAnnotations(div, pdfPage, this.viewport);
    div.setAttribute('data-loaded', true);

    // Add the page to the cache at the start of drawing. That way it can be
    // evicted from the cache and destroyed even if we pause its rendering.
    cache.push(this);
  };

  this.beforePrint = function pageViewBeforePrint() {
    var pdfPage = this.pdfPage;

    var viewport = pdfPage.getViewport(1);
    // Use the same hack we use for high dpi displays for printing to get better
    // output until bug 811002 is fixed in FF.
    var PRINT_OUTPUT_SCALE = 2;
    var canvas = document.createElement('canvas');
    canvas.width = Math.floor(viewport.width) * PRINT_OUTPUT_SCALE;
    canvas.height = Math.floor(viewport.height) * PRINT_OUTPUT_SCALE;
    canvas.style.width = (PRINT_OUTPUT_SCALE * viewport.width) + 'pt';
    canvas.style.height = (PRINT_OUTPUT_SCALE * viewport.height) + 'pt';
    var cssScale = 'scale(' + (1 / PRINT_OUTPUT_SCALE) + ', ' +
                              (1 / PRINT_OUTPUT_SCALE) + ')';
    CustomStyle.setProp('transform' , canvas, cssScale);
    CustomStyle.setProp('transformOrigin' , canvas, '0% 0%');

    var printContainer = document.getElementById('printContainer');
    var canvasWrapper = document.createElement('div');
    canvasWrapper.style.width = viewport.width + 'pt';
    canvasWrapper.style.height = viewport.height + 'pt';
    canvasWrapper.appendChild(canvas);
    printContainer.appendChild(canvasWrapper);

    canvas.mozPrintCallback = function(obj) {
      var ctx = obj.context;

      ctx.save();
      ctx.fillStyle = 'rgb(255, 255, 255)';
      ctx.fillRect(0, 0, canvas.width, canvas.height);
      ctx.restore();
      ctx.scale(PRINT_OUTPUT_SCALE, PRINT_OUTPUT_SCALE);

      var renderContext = {
        canvasContext: ctx,
        viewport: viewport,
        intent: 'print'
      };

      pdfPage.render(renderContext).promise.then(function() {
        // Tell the printEngine that rendering this canvas/page has finished.
        obj.done();
      }, function(error) {
        console.error(error);
        // Tell the printEngine that rendering this canvas/page has failed.
        // This will make the print proces stop.
        if ('abort' in obj) {
          obj.abort();
        } else {
          obj.done();
        }
      });
    };
  };

  this.updateStats = function pageViewUpdateStats() {
    if (!this.stats) {
      return;
    }

    if (PDFJS.pdfBug && Stats.enabled) {
      var stats = this.stats;
      Stats.add(this.id, stats);
    }
  };
};


var FIND_SCROLL_OFFSET_TOP = -50;
var FIND_SCROLL_OFFSET_LEFT = -400;
var MAX_TEXT_DIVS_TO_RENDER = 100000;
var RENDER_DELAY = 200; // ms

var NonWhitespaceRegexp = /\S/;

function isAllWhitespace(str) {
  return !NonWhitespaceRegexp.test(str);
}

/**
 * @typedef {Object} TextLayerBuilderOptions
 * @property {HTMLDivElement} textLayerDiv - The text layer container.
 * @property {number} pageIndex - The page index.
 * @property {PageViewport} viewport - The viewport of the text layer.
 * @property {ILastScrollSource} lastScrollSource - The object that records when
 *   last time scroll happened.
 * @property {boolean} isViewerInPresentationMode
 * @property {PDFFindController} findController
 */

/**
 * TextLayerBuilder provides text-selection functionality for the PDF.
 * It does this by creating overlay divs over the PDF text. These divs
 * contain text that matches the PDF text they are overlaying. This object
 * also provides a way to highlight text that is being searched for.
 * @class
 */
var TextLayerBuilder = (function TextLayerBuilderClosure() {
  function TextLayerBuilder(options) {
    this.textLayerDiv = options.textLayerDiv;
    this.layoutDone = false;
    this.divContentDone = false;
    this.pageIdx = options.pageIndex;
    this.matches = [];
    this.lastScrollSource = options.lastScrollSource || null;
    this.viewport = options.viewport;
    this.isViewerInPresentationMode = options.isViewerInPresentationMode;
    this.textDivs = [];
    this.findController = options.findController || null;
  }

  TextLayerBuilder.prototype = {
    renderLayer: function TextLayerBuilder_renderLayer() {
      var textLayerFrag = document.createDocumentFragment();
      var textDivs = this.textDivs;
      var textDivsLength = textDivs.length;
      var canvas = document.createElement('canvas');
      var ctx = canvas.getContext('2d');

      // No point in rendering many divs as it would make the browser
      // unusable even after the divs are rendered.
      if (textDivsLength > MAX_TEXT_DIVS_TO_RENDER) {
        return;
      }

      var lastFontSize;
      var lastFontFamily;
      for (var i = 0; i < textDivsLength; i++) {
        var textDiv = textDivs[i];
        if (textDiv.dataset.isWhitespace !== undefined) {
          continue;
        }

        var fontSize = textDiv.style.fontSize;
        var fontFamily = textDiv.style.fontFamily;

        // Only build font string and set to context if different from last.
        if (fontSize !== lastFontSize || fontFamily !== lastFontFamily) {
          ctx.font = fontSize + ' ' + fontFamily;
          lastFontSize = fontSize;
          lastFontFamily = fontFamily;
        }

        var width = ctx.measureText(textDiv.textContent).width;
        if (width > 0) {
          textLayerFrag.appendChild(textDiv);
          var transform;
          if (textDiv.dataset.canvasWidth !== undefined) {
            // Dataset values come of type string.
            var textScale = textDiv.dataset.canvasWidth / width;
            transform = 'scaleX(' + textScale + ')';
          } else {
            transform = '';
          }
          var rotation = textDiv.dataset.angle;
          if (rotation) {
            transform = 'rotate(' + rotation + 'deg) ' + transform;
          }
          if (transform) {
            CustomStyle.setProp('transform' , textDiv, transform);
          }
        }
      }

      this.textLayerDiv.appendChild(textLayerFrag);
      this.renderingDone = true;
      this.updateMatches();
    },

    setupRenderLayoutTimer:
        function TextLayerBuilder_setupRenderLayoutTimer() {
      // Schedule renderLayout() if the user has been scrolling,
      // otherwise run it right away.
      var self = this;
      var lastScroll = (this.lastScrollSource === null ?
                        0 : this.lastScrollSource.lastScroll);

      if (Date.now() - lastScroll > RENDER_DELAY) { // Render right away
        this.renderLayer();
      } else { // Schedule
        if (this.renderTimer) {
          clearTimeout(this.renderTimer);
        }
        this.renderTimer = setTimeout(function() {
          self.setupRenderLayoutTimer();
        }, RENDER_DELAY);
      }
    },

    appendText: function TextLayerBuilder_appendText(geom, styles) {
      var style = styles[geom.fontName];
      var textDiv = document.createElement('div');
      this.textDivs.push(textDiv);
      if (isAllWhitespace(geom.str)) {
        textDiv.dataset.isWhitespace = true;
        return;
      }
      var tx = PDFJS.Util.transform(this.viewport.transform, geom.transform);
      var angle = Math.atan2(tx[1], tx[0]);
      if (style.vertical) {
        angle += Math.PI / 2;
      }
      var fontHeight = Math.sqrt((tx[2] * tx[2]) + (tx[3] * tx[3]));
      var fontAscent = fontHeight;
      if (style.ascent) {
        fontAscent = style.ascent * fontAscent;
      } else if (style.descent) {
        fontAscent = (1 + style.descent) * fontAscent;
      }

      var left;
      var top;
      if (angle === 0) {
        left = tx[4];
        top = tx[5] - fontAscent;
      } else {
        left = tx[4] + (fontAscent * Math.sin(angle));
        top = tx[5] - (fontAscent * Math.cos(angle));
      }
      textDiv.style.left = left + 'px';
      textDiv.style.top = top + 'px';
      textDiv.style.fontSize = fontHeight + 'px';
      textDiv.style.fontFamily = style.fontFamily;

      textDiv.textContent = geom.str;
      // |fontName| is only used by the Font Inspector. This test will succeed
      // when e.g. the Font Inspector is off but the Stepper is on, but it's
      // not worth the effort to do a more accurate test.
      if (PDFJS.pdfBug) {
        textDiv.dataset.fontName = geom.fontName;
      }
      // Storing into dataset will convert number into string.
      if (angle !== 0) {
        textDiv.dataset.angle = angle * (180 / Math.PI);
      }
      // We don't bother scaling single-char text divs, because it has very
      // little effect on text highlighting. This makes scrolling on docs with
      // lots of such divs a lot faster.
      if (textDiv.textContent.length > 1) {
        if (style.vertical) {
          textDiv.dataset.canvasWidth = geom.height * this.viewport.scale;
        } else {
          textDiv.dataset.canvasWidth = geom.width * this.viewport.scale;
        }
      }
    },

    setTextContent: function TextLayerBuilder_setTextContent(textContent) {
      this.textContent = textContent;

      var textItems = textContent.items;
      for (var i = 0, len = textItems.length; i < len; i++) {
        this.appendText(textItems[i], textContent.styles);
      }
      this.divContentDone = true;
      this.setupRenderLayoutTimer();
    },

    convertMatches: function TextLayerBuilder_convertMatches(matches) {
      var i = 0;
      var iIndex = 0;
      var bidiTexts = this.textContent.items;
      var end = bidiTexts.length - 1;
      var queryLen = (this.findController === null ?
                      0 : this.findController.state.query.length);
      var ret = [];

      for (var m = 0, len = matches.length; m < len; m++) {
        // Calculate the start position.
        var matchIdx = matches[m];

        // Loop over the divIdxs.
        while (i !== end && matchIdx >= (iIndex + bidiTexts[i].str.length)) {
          iIndex += bidiTexts[i].str.length;
          i++;
        }

        if (i === bidiTexts.length) {
          console.error('Could not find a matching mapping');
        }

        var match = {
          begin: {
            divIdx: i,
            offset: matchIdx - iIndex
          }
        };

        // Calculate the end position.
        matchIdx += queryLen;

        // Somewhat the same array as above, but use > instead of >= to get
        // the end position right.
        while (i !== end && matchIdx > (iIndex + bidiTexts[i].str.length)) {
          iIndex += bidiTexts[i].str.length;
          i++;
        }

        match.end = {
          divIdx: i,
          offset: matchIdx - iIndex
        };
        ret.push(match);
      }

      return ret;
    },

    renderMatches: function TextLayerBuilder_renderMatches(matches) {
      // Early exit if there is nothing to render.
      if (matches.length === 0) {
        return;
      }

      var bidiTexts = this.textContent.items;
      var textDivs = this.textDivs;
      var prevEnd = null;
      var isSelectedPage = (this.findController === null ?
        false : (this.pageIdx === this.findController.selected.pageIdx));
      var selectedMatchIdx = (this.findController === null ?
                              -1 : this.findController.selected.matchIdx);
      var highlightAll = (this.findController === null ?
                          false : this.findController.state.highlightAll);
      var infinity = {
        divIdx: -1,
        offset: undefined
      };

      function beginText(begin, className) {
        var divIdx = begin.divIdx;
        textDivs[divIdx].textContent = '';
        appendTextToDiv(divIdx, 0, begin.offset, className);
      }

      function appendTextToDiv(divIdx, fromOffset, toOffset, className) {
        var div = textDivs[divIdx];
        var content = bidiTexts[divIdx].str.substring(fromOffset, toOffset);
        var node = document.createTextNode(content);
        if (className) {
          var span = document.createElement('span');
          span.className = className;
          span.appendChild(node);
          div.appendChild(span);
          return;
        }
        div.appendChild(node);
      }

      var i0 = selectedMatchIdx, i1 = i0 + 1;
      if (highlightAll) {
        i0 = 0;
        i1 = matches.length;
      } else if (!isSelectedPage) {
        // Not highlighting all and this isn't the selected page, so do nothing.
        return;
      }

      for (var i = i0; i < i1; i++) {
        var match = matches[i];
        var begin = match.begin;
        var end = match.end;
        var isSelected = (isSelectedPage && i === selectedMatchIdx);
        var highlightSuffix = (isSelected ? ' selected' : '');

        if (isSelected && !this.isViewerInPresentationMode) {
          scrollIntoView(textDivs[begin.divIdx],
                         { top: FIND_SCROLL_OFFSET_TOP,
                           left: FIND_SCROLL_OFFSET_LEFT });
        }

        // Match inside new div.
        if (!prevEnd || begin.divIdx !== prevEnd.divIdx) {
          // If there was a previous div, then add the text at the end.
          if (prevEnd !== null) {
            appendTextToDiv(prevEnd.divIdx, prevEnd.offset, infinity.offset);
          }
          // Clear the divs and set the content until the starting point.
          beginText(begin);
        } else {
          appendTextToDiv(prevEnd.divIdx, prevEnd.offset, begin.offset);
        }

        if (begin.divIdx === end.divIdx) {
          appendTextToDiv(begin.divIdx, begin.offset, end.offset,
                          'highlight' + highlightSuffix);
        } else {
          appendTextToDiv(begin.divIdx, begin.offset, infinity.offset,
                          'highlight begin' + highlightSuffix);
          for (var n0 = begin.divIdx + 1, n1 = end.divIdx; n0 < n1; n0++) {
            textDivs[n0].className = 'highlight middle' + highlightSuffix;
          }
          beginText(end, 'highlight end' + highlightSuffix);
        }
        prevEnd = end;
      }

      if (prevEnd) {
        appendTextToDiv(prevEnd.divIdx, prevEnd.offset, infinity.offset);
      }
    },

    updateMatches: function TextLayerBuilder_updateMatches() {
      // Only show matches when all rendering is done.
      if (!this.renderingDone) {
        return;
      }

      // Clear all matches.
      var matches = this.matches;
      var textDivs = this.textDivs;
      var bidiTexts = this.textContent.items;
      var clearedUntilDivIdx = -1;

      // Clear all current matches.
      for (var i = 0, len = matches.length; i < len; i++) {
        var match = matches[i];
        var begin = Math.max(clearedUntilDivIdx, match.begin.divIdx);
        for (var n = begin, end = match.end.divIdx; n <= end; n++) {
          var div = textDivs[n];
          div.textContent = bidiTexts[n].str;
          div.className = '';
        }
        clearedUntilDivIdx = match.end.divIdx + 1;
      }

      if (this.findController === null || !this.findController.active) {
        return;
      }

      // Convert the matches on the page controller into the match format
      // used for the textLayer.
      this.matches = this.convertMatches(this.findController === null ?
        [] : (this.findController.pageMatches[this.pageIdx] || []));
      this.renderMatches(this.matches);
    }
  };
  return TextLayerBuilder;
})();


/**
 * @typedef {Object} PDFViewerOptions
 * @property {HTMLDivElement} container - The container for the viewer element.
 * @property {HTMLDivElement} viewer - (optional) The viewer element.
 * @property {IPDFLinkService} linkService - The navigation/linking service.
 * @property {PDFRenderingQueue} renderingQueue - (optional) The rendering
 *   queue object.
 */

/**
 * Simple viewer control to display PDF content/pages.
 * @class
 * @implements {ILastScrollSource}
 * @implements {IRenderableView}
 */
var PDFViewer = (function pdfViewer() {
  /**
   * @constructs PDFViewer
   * @param {PDFViewerOptions} options
   */
  function PDFViewer(options) {
    this.container = options.container;
    this.viewer = options.viewer || options.container.firstElementChild;
    this.linkService = options.linkService || new SimpleLinkService(this);

    this.defaultRenderingQueue = !options.renderingQueue;
    if (this.defaultRenderingQueue) {
      // Custom rendering queue is not specified, using default one
      this.renderingQueue = new PDFRenderingQueue();
      this.renderingQueue.setViewer(this);
    } else {
      this.renderingQueue = options.renderingQueue;
    }

    this.scroll = watchScroll(this.container, this._scrollUpdate.bind(this));
    this.lastScroll = 0;
    this.updateInProgress = false;
    this.presentationModeState = PresentationModeState.UNKNOWN;
    this._resetView();
  }

  PDFViewer.prototype = /** @lends PDFViewer.prototype */{
    get pagesCount() {
      return this.pages.length;
    },

    getPageView: function (index) {
      return this.pages[index];
    },

    get currentPageNumber() {
      return this._currentPageNumber;
    },

    set currentPageNumber(val) {
      if (!this.pdfDocument) {
        this._currentPageNumber = val;
        return;
      }

      var event = document.createEvent('UIEvents');
      event.initUIEvent('pagechange', true, true, window, 0);
      event.updateInProgress = this.updateInProgress;

      if (!(0 < val && val <= this.pagesCount)) {
        event.pageNumber = this._currentPageNumber;
        event.previousPageNumber = val;
        this.container.dispatchEvent(event);
        return;
      }

      this.pages[val - 1].updateStats();
      event.previousPageNumber = this._currentPageNumber;
      this._currentPageNumber = val;
      event.pageNumber = val;
      this.container.dispatchEvent(event);
    },

    /**
     * @returns {number}
     */
    get currentScale() {
      return this._currentScale;
    },

    /**
     * @param {number} val - Scale of the pages in percents.
     */
    set currentScale(val) {
      if (isNaN(val))  {
        throw new Error('Invalid numeric scale');
      }
      if (!this.pdfDocument) {
        this._currentScale = val;
        this._currentScaleValue = val.toString();
        return;
      }
      this._setScale(val, false);
    },

    /**
     * @returns {string}
     */
    get currentScaleValue() {
      return this._currentScaleValue;
    },

    /**
     * @param val - The scale of the pages (in percent or predefined value).
     */
    set currentScaleValue(val) {
      if (!this.pdfDocument) {
        this._currentScale = isNaN(val) ? UNKNOWN_SCALE : val;
        this._currentScaleValue = val;
        return;
      }
      this._setScale(val, false);
    },

    /**
     * @returns {number}
     */
    get pagesRotation() {
      return this._pagesRotation;
    },

    /**
     * @param {number} rotation - The rotation of the pages (0, 90, 180, 270).
     */
    set pagesRotation(rotation) {
      this._pagesRotation = rotation;

      for (var i = 0, l = this.pages.length; i < l; i++) {
        var page = this.pages[i];
        page.update(page.scale, rotation);
      }

      this._setScale(this._currentScaleValue, true);
    },

    /**
     * @param pdfDocument {PDFDocument}
     */
    setDocument: function (pdfDocument) {
      if (this.pdfDocument) {
        this._resetView();
      }

      this.pdfDocument = pdfDocument;
      if (!pdfDocument) {
        return;
      }

      var pagesCount = pdfDocument.numPages;
      var pagesRefMap = this.pagesRefMap = {};
      var self = this;

      var resolvePagesPromise;
      var pagesPromise = new Promise(function (resolve) {
        resolvePagesPromise = resolve;
      });
      this.pagesPromise = pagesPromise;
      pagesPromise.then(function () {
        var event = document.createEvent('CustomEvent');
        event.initCustomEvent('pagesloaded', true, true, {
          pagesCount: pagesCount
        });
        self.container.dispatchEvent(event);
      });

      var isOnePageRenderedResolved = false;
      var resolveOnePageRendered = null;
      var onePageRendered = new Promise(function (resolve) {
        resolveOnePageRendered = resolve;
      });
      this.onePageRendered = onePageRendered;

      var bindOnAfterDraw = function (pageView) {
        // when page is painted, using the image as thumbnail base
        pageView.onAfterDraw = function pdfViewLoadOnAfterDraw() {
          if (!isOnePageRenderedResolved) {
            isOnePageRenderedResolved = true;
            resolveOnePageRendered();
          }
          var event = document.createEvent('CustomEvent');
          event.initCustomEvent('pagerendered', true, true, {
            pageNumber: pageView.id
          });
          self.container.dispatchEvent(event);
        };
      };

      var firstPagePromise = pdfDocument.getPage(1);
      this.firstPagePromise = firstPagePromise;

      // Fetch a single page so we can get a viewport that will be the default
      // viewport for all pages
      return firstPagePromise.then(function(pdfPage) {
        var scale = this._currentScale || 1.0;
        var viewport = pdfPage.getViewport(scale * CSS_UNITS);
        for (var pageNum = 1; pageNum <= pagesCount; ++pageNum) {
          var pageSource = new PDFPageSource(pdfDocument, pageNum);
          var pageView = new PageView(this.viewer, pageNum, scale,
                                      viewport.clone(), this.linkService,
                                      this.renderingQueue, this.cache,
                                      pageSource, this);
          bindOnAfterDraw(pageView);
          this.pages.push(pageView);
        }

        // Fetch all the pages since the viewport is needed before printing
        // starts to create the correct size canvas. Wait until one page is
        // rendered so we don't tie up too many resources early on.
        onePageRendered.then(function () {
          if (!PDFJS.disableAutoFetch) {
            var getPagesLeft = pagesCount;
            for (var pageNum = 1; pageNum <= pagesCount; ++pageNum) {
              pdfDocument.getPage(pageNum).then(function (pageNum, pdfPage) {
                var pageView = self.pages[pageNum - 1];
                if (!pageView.pdfPage) {
                  pageView.setPdfPage(pdfPage);
                }
                var refStr = pdfPage.ref.num + ' ' + pdfPage.ref.gen + ' R';
                pagesRefMap[refStr] = pageNum;
                getPagesLeft--;
                if (!getPagesLeft) {
                  resolvePagesPromise();
                }
              }.bind(null, pageNum));
            }
          } else {
            // XXX: Printing is semi-broken with auto fetch disabled.
            resolvePagesPromise();
          }
        });

        var event = document.createEvent('CustomEvent');
        event.initCustomEvent('pagesinit', true, true, null);
        self.container.dispatchEvent(event);

        if (this.defaultRenderingQueue) {
          this.update();
        }
      }.bind(this));
    },

    _resetView: function () {
      this.cache = new Cache(DEFAULT_CACHE_SIZE);
      this.pages = [];
      this._currentPageNumber = 1;
      this._currentScale = UNKNOWN_SCALE;
      this._currentScaleValue = null;
      this.location = null;
      this._pagesRotation = 0;

      var container = this.viewer;
      while (container.hasChildNodes()) {
        container.removeChild(container.lastChild);
      }
    },

    _scrollUpdate: function () {
      this.lastScroll = Date.now();

      if (this.pagesCount === 0) {
        return;
      }
      this.update();
    },

    _setScaleUpdatePages: function pdfViewer_setScaleUpdatePages(
        newScale, newValue, noScroll, preset) {
      this._currentScaleValue = newValue;
      if (newScale === this._currentScale) {
        return;
      }
      for (var i = 0, ii = this.pages.length; i < ii; i++) {
        this.pages[i].update(newScale);
      }
      this._currentScale = newScale;

      if (!noScroll) {
        var page = this._currentPageNumber, dest;
        var inPresentationMode =
          this.presentationModeState === PresentationModeState.CHANGING ||
          this.presentationModeState === PresentationModeState.FULLSCREEN;
        if (this.location && !inPresentationMode &&
            !IGNORE_CURRENT_POSITION_ON_ZOOM) {
          page = this.location.pageNumber;
          dest = [null, { name: 'XYZ' }, this.location.left,
            this.location.top, null];
        }
        this.scrollPageIntoView(page, dest);
      }

      var event = document.createEvent('UIEvents');
      event.initUIEvent('scalechange', true, true, window, 0);
      event.scale = newScale;
      if (preset) {
        event.presetValue = newValue;
      }
      this.container.dispatchEvent(event);
    },

    _setScale: function pdfViewer_setScale(value, noScroll) {
      if (value === 'custom') {
        return;
      }
      var scale = parseFloat(value);

      if (scale > 0) {
        this._setScaleUpdatePages(scale, value, noScroll, false);
      } else {
        var currentPage = this.pages[this._currentPageNumber - 1];
        if (!currentPage) {
          return;
        }
        var inPresentationMode =
          this.presentationModeState === PresentationModeState.FULLSCREEN;
        var hPadding = inPresentationMode ? 0 : SCROLLBAR_PADDING;
        var vPadding = inPresentationMode ? 0 : VERTICAL_PADDING;
        var pageWidthScale = (this.container.clientWidth - hPadding) /
                             currentPage.width * currentPage.scale;
        var pageHeightScale = (this.container.clientHeight - vPadding) /
                              currentPage.height * currentPage.scale;
        switch (value) {
          case 'page-actual':
            scale = 1;
            break;
          case 'page-width':
            scale = pageWidthScale;
            break;
          case 'page-height':
            scale = pageHeightScale;
            break;
          case 'page-fit':
            scale = Math.min(pageWidthScale, pageHeightScale);
            break;
          case 'auto':
            var isLandscape = (currentPage.width > currentPage.height);
            var horizontalScale = isLandscape ? pageHeightScale :
                                                pageWidthScale;
            scale = Math.min(MAX_AUTO_SCALE, horizontalScale);
            break;
          default:
            console.error('pdfViewSetScale: \'' + value +
              '\' is an unknown zoom value.');
            return;
        }
        this._setScaleUpdatePages(scale, value, noScroll, true);
      }
    },

    /**
     * Scrolls page into view.
     * @param {number} pageNumber
     * @param {Array} dest - (optional) original PDF destination array:
     *   <page-ref> </XYZ|FitXXX> <args..>
     */
    scrollPageIntoView: function PDFViewer_scrollPageIntoView(pageNumber,
                                                              dest) {
      var pageView = this.pages[pageNumber - 1];
      var pageViewDiv = pageView.el;

      if (this.presentationModeState ===
        PresentationModeState.FULLSCREEN) {
        if (this.linkService.page !== pageView.id) {
          // Avoid breaking getVisiblePages in presentation mode.
          this.linkService.page = pageView.id;
          return;
        }
        dest = null;
        // Fixes the case when PDF has different page sizes.
        this._setScale(this.currentScaleValue, true);
      }
      if (!dest) {
        scrollIntoView(pageViewDiv);
        return;
      }

      var x = 0, y = 0;
      var width = 0, height = 0, widthScale, heightScale;
      var changeOrientation = (pageView.rotation % 180 === 0 ? false : true);
      var pageWidth = (changeOrientation ? pageView.height : pageView.width) /
        pageView.scale / CSS_UNITS;
      var pageHeight = (changeOrientation ? pageView.width : pageView.height) /
        pageView.scale / CSS_UNITS;
      var scale = 0;
      switch (dest[1].name) {
        case 'XYZ':
          x = dest[2];
          y = dest[3];
          scale = dest[4];
          // If x and/or y coordinates are not supplied, default to
          // _top_ left of the page (not the obvious bottom left,
          // since aligning the bottom of the intended page with the
          // top of the window is rarely helpful).
          x = x !== null ? x : 0;
          y = y !== null ? y : pageHeight;
          break;
        case 'Fit':
        case 'FitB':
          scale = 'page-fit';
          break;
        case 'FitH':
        case 'FitBH':
          y = dest[2];
          scale = 'page-width';
          break;
        case 'FitV':
        case 'FitBV':
          x = dest[2];
          width = pageWidth;
          height = pageHeight;
          scale = 'page-height';
          break;
        case 'FitR':
          x = dest[2];
          y = dest[3];
          width = dest[4] - x;
          height = dest[5] - y;
          var viewerContainer = this.container;
          widthScale = (viewerContainer.clientWidth - SCROLLBAR_PADDING) /
            width / CSS_UNITS;
          heightScale = (viewerContainer.clientHeight - SCROLLBAR_PADDING) /
            height / CSS_UNITS;
          scale = Math.min(Math.abs(widthScale), Math.abs(heightScale));
          break;
        default:
          return;
      }

      if (scale && scale !== this.currentScale) {
        this.currentScaleValue = scale;
      } else if (this.currentScale === UNKNOWN_SCALE) {
        this.currentScaleValue = DEFAULT_SCALE;
      }

      if (scale === 'page-fit' && !dest[4]) {
        scrollIntoView(pageViewDiv);
        return;
      }

      var boundingRect = [
        pageView.viewport.convertToViewportPoint(x, y),
        pageView.viewport.convertToViewportPoint(x + width, y + height)
      ];
      var left = Math.min(boundingRect[0][0], boundingRect[1][0]);
      var top = Math.min(boundingRect[0][1], boundingRect[1][1]);

      scrollIntoView(pageViewDiv, { left: left, top: top });
    },

    _updateLocation: function (firstPage) {
      var currentScale = this._currentScale;
      var currentScaleValue = this._currentScaleValue;
      var normalizedScaleValue =
        parseFloat(currentScaleValue) === currentScale ?
        Math.round(currentScale * 10000) / 100 : currentScaleValue;

      var pageNumber = firstPage.id;
      var pdfOpenParams = '#page=' + pageNumber;
      pdfOpenParams += '&zoom=' + normalizedScaleValue;
      var currentPageView = this.pages[pageNumber - 1];
      var container = this.container;
      var topLeft = currentPageView.getPagePoint(
        (container.scrollLeft - firstPage.x),
        (container.scrollTop - firstPage.y));
      var intLeft = Math.round(topLeft[0]);
      var intTop = Math.round(topLeft[1]);
      pdfOpenParams += ',' + intLeft + ',' + intTop;

      this.location = {
        pageNumber: pageNumber,
        scale: normalizedScaleValue,
        top: intTop,
        left: intLeft,
        pdfOpenParams: pdfOpenParams
      };
    },

    update: function () {
      var visible = this._getVisiblePages();
      var visiblePages = visible.views;
      if (visiblePages.length === 0) {
        return;
      }

      this.updateInProgress = true;

      var suggestedCacheSize = Math.max(DEFAULT_CACHE_SIZE,
          2 * visiblePages.length + 1);
      this.cache.resize(suggestedCacheSize);

      this.renderingQueue.renderHighestPriority(visible);

      var currentId = this.currentPageNumber;
      var firstPage = visible.first;

      for (var i = 0, ii = visiblePages.length, stillFullyVisible = false;
           i < ii; ++i) {
        var page = visiblePages[i];

        if (page.percent < 100) {
          break;
        }
        if (page.id === currentId) {
          stillFullyVisible = true;
          break;
        }
      }

      if (!stillFullyVisible) {
        currentId = visiblePages[0].id;
      }

      if (this.presentationModeState !== PresentationModeState.FULLSCREEN) {
        this.currentPageNumber = currentId;
      }

      this._updateLocation(firstPage);

      this.updateInProgress = false;

      var event = document.createEvent('UIEvents');
      event.initUIEvent('updateviewarea', true, true, window, 0);
      this.container.dispatchEvent(event);
    },

    containsElement: function (element) {
      return this.container.contains(element);
    },

    focus: function () {
      this.container.focus();
    },

    blur: function () {
      this.container.blur();
    },

    get isHorizontalScrollbarEnabled() {
      return (this.presentationModeState === PresentationModeState.FULLSCREEN ?
        false : (this.container.scrollWidth > this.container.clientWidth));
    },

    _getVisiblePages: function () {
      if (this.presentationModeState !== PresentationModeState.FULLSCREEN) {
        return getVisibleElements(this.container, this.pages, true);
      } else {
        // The algorithm in getVisibleElements doesn't work in all browsers and
        // configurations when presentation mode is active.
        var visible = [];
        var currentPage = this.pages[this._currentPageNumber - 1];
        visible.push({ id: currentPage.id, view: currentPage });
        return { first: currentPage, last: currentPage, views: visible };
      }
    },

    cleanup: function () {
      for (var i = 0, ii = this.pages.length; i < ii; i++) {
        if (this.pages[i] &&
          this.pages[i].renderingState !== RenderingStates.FINISHED) {
          this.pages[i].reset();
        }
      }
    },

    forceRendering: function (currentlyVisiblePages) {
      var visiblePages = currentlyVisiblePages || this._getVisiblePages();
      var pageView = this.renderingQueue.getHighestPriority(visiblePages,
                                                            this.pages,
                                                            this.scroll.down);
      if (pageView) {
        this.renderingQueue.renderView(pageView);
        return;
      }
    },

    getPageTextContent: function (pageIndex) {
      return this.pdfDocument.getPage(pageIndex + 1).then(function (page) {
        return page.getTextContent();
      });
    },

    /**
     * @param textLayerDiv {HTMLDivElement}
     * @param pageIndex {number}
     * @param viewport {PageViewport}
     * @returns {TextLayerBuilder}
     */
    createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport) {
      var isViewerInPresentationMode =
        this.presentationModeState === PresentationModeState.FULLSCREEN;
      return new TextLayerBuilder({
        textLayerDiv: textLayerDiv,
        pageIndex: pageIndex,
        viewport: viewport,
        lastScrollSource: this,
        isViewerInPresentationMode: isViewerInPresentationMode,
        findController: this.findController
      });
    },

    setFindController: function (findController) {
      this.findController = findController;
    },
  };

  return PDFViewer;
})();

var SimpleLinkService = (function SimpleLinkServiceClosure() {
  function SimpleLinkService(pdfViewer) {
    this.pdfViewer = pdfViewer;
  }
  SimpleLinkService.prototype = {
    /**
     * @returns {number}
     */
    get page() {
      return this.pdfViewer.currentPageNumber;
    },
    /**
     * @param {number} value
     */
    set page(value) {
      this.pdfViewer.currentPageNumber = value;
    },
    /**
     * @param dest - The PDF destination object.
     */
    navigateTo: function (dest) {},
    /**
     * @param dest - The PDF destination object.
     * @returns {string} The hyperlink to the PDF object.
     */
    getDestinationHash: function (dest) {
      return '#';
    },
    /**
     * @param hash - The PDF parameters/hash.
     * @returns {string} The hyperlink to the PDF object.
     */
    getAnchorUrl: function (hash) {
      return '#';
    },
    /**
     * @param {string} hash
     */
    setHash: function (hash) {},
    /**
     * @param {string} action
     */
    executeNamedAction: function (action) {},
  };
  return SimpleLinkService;
})();

/**
 * PDFPage object source.
 * @class
 */
var PDFPageSource = (function PDFPageSourceClosure() {
  /**
   * @constructs
   * @param {PDFDocument} pdfDocument
   * @param {number} pageNumber
   * @constructor
   */
  function PDFPageSource(pdfDocument, pageNumber) {
    this.pdfDocument = pdfDocument;
    this.pageNumber = pageNumber;
  }

  PDFPageSource.prototype = /** @lends PDFPageSource.prototype */ {
    /**
     * @returns {Promise<PDFPage>}
     */
    getPage: function () {
      return this.pdfDocument.getPage(this.pageNumber);
    }
  };

  return PDFPageSource;
})();


  PDFJS.PDFViewer = PDFViewer;
}).call((typeof window === 'undefined') ? this : window);