chrome/browser/resources/pdf/open_pdf_params_parser.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 'use strict';
   6
   7 /**
   8  * Creates a new OpenPDFParamsParser. This parses the open pdf parameters
   9  * passed in the url to set initial viewport settings for opening the pdf.
  10  * @param {Object} getNamedDestinationsFunction The function called to fetch
  11  *     the page number for a named destination.
  12  */
  13 function OpenPDFParamsParser(getNamedDestinationsFunction) {
  14   this.outstandingRequests_ = [];
  15   this.getNamedDestinationsFunction_ = getNamedDestinationsFunction;
  16 }
  17
  18 OpenPDFParamsParser.prototype = {
  19   /**
  20    * @private
  21    * Parse zoom parameter of open PDF parameters. If this
  22    * parameter is passed while opening PDF then PDF should be opened
  23    * at the specified zoom level.
  24    * @param {number} zoom value.
  25    * @param {Object} viewportPosition to store zoom and position value.
  26    */
  27   parseZoomParam_: function(paramValue, viewportPosition) {
  28     var paramValueSplit = paramValue.split(',');
  29     if ((paramValueSplit.length != 1) && (paramValueSplit.length != 3))
  30       return;
  31
  32     // User scale of 100 means zoom value of 100% i.e. zoom factor of 1.0.
  33     var zoomFactor = parseFloat(paramValueSplit[0]) / 100;
  34     if (isNaN(zoomFactor))
  35       return;
  36
  37     // Handle #zoom=scale.
  38     if (paramValueSplit.length == 1) {
  39       viewportPosition['zoom'] = zoomFactor;
  40       return;
  41     }
  42
  43     // Handle #zoom=scale,left,top.
  44     var position = {x: parseFloat(paramValueSplit[1]),
  45                     y: parseFloat(paramValueSplit[2])};
  46     viewportPosition['position'] = position;
  47     viewportPosition['zoom'] = zoomFactor;
  48   },
  49
  50   /**
  51    * @private
  52    * Parse PDF url parameters. These parameters are mentioned in the url
  53    * and specify actions to be performed when opening pdf files.
  54    * See http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/
  55    * pdfs/pdf_open_parameters.pdf for details.
  56    * @param {string} url that needs to be parsed.
  57    * @param {Function} callback function to be called with viewport info.
  58    */
  59   getViewportFromUrlParams: function(url, callback) {
  60     var viewportPosition = {};
  61     viewportPosition['url'] = url;
  62     var paramIndex = url.search('#');
  63     if (paramIndex == -1) {
  64       callback(viewportPosition);
  65       return;
  66     }
  67
  68     var paramTokens = url.substring(paramIndex + 1).split('&');
  69     if ((paramTokens.length == 1) && (paramTokens[0].search('=') == -1)) {
  70       // Handle the case of http://foo.com/bar#NAMEDDEST. This is not
  71       // explicitly mentioned except by example in the Adobe
  72       // "PDF Open Parameters" document.
  73       this.outstandingRequests_.push({
  74         callback: callback,
  75         viewportPosition: viewportPosition
  76       });
  77       this.getNamedDestinationsFunction_(paramTokens[0]);
  78       return;
  79     }
  80
  81     var paramsDictionary = {};
  82     for (var i = 0; i < paramTokens.length; ++i) {
  83       var keyValueSplit = paramTokens[i].split('=');
  84       if (keyValueSplit.length != 2)
  85         continue;
  86       paramsDictionary[keyValueSplit[0]] = keyValueSplit[1];
  87     }
  88
  89     if ('page' in paramsDictionary) {
  90       // |pageNumber| is 1-based, but goToPage() take a zero-based page number.
  91       var pageNumber = parseInt(paramsDictionary['page']);
  92       if (!isNaN(pageNumber) && pageNumber > 0)
  93         viewportPosition['page'] = pageNumber - 1;
  94     }
  95
  96     if ('zoom' in paramsDictionary)
  97       this.parseZoomParam_(paramsDictionary['zoom'], viewportPosition);
  98
  99     if (viewportPosition.page === undefined &&
 100         'nameddest' in paramsDictionary) {
 101       this.outstandingRequests_.push({
 102         callback: callback,
 103         viewportPosition: viewportPosition
 104       });
 105       this.getNamedDestinationsFunction_(paramsDictionary['nameddest']);
 106     } else {
 107       callback(viewportPosition);
 108     }
 109   },
 110
 111   /**
 112    * This is called when a named destination is received and the page number
 113    * corresponding to the request for which a named destination is passed.
 114    * @param {number} pageNumber The page corresponding to the named destination
 115    *    requested.
 116    */
 117   onNamedDestinationReceived: function(pageNumber) {
 118     var outstandingRequest = this.outstandingRequests_.shift();
 119     if (pageNumber != -1)
 120       outstandingRequest.viewportPosition.page = pageNumber;
 121     outstandingRequest.callback(outstandingRequest.viewportPosition);
 122   },
 123 };