pdfjs-dist/lib/web/preferences.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 defaultPreferences = null;
function getDefaultPreferences() {
 if (!defaultPreferences) {
  defaultPreferences = Promise.resolve({
   "showPreviousViewOnLoad": true,
   "defaultZoomValue": "",
   "sidebarViewOnLoad": 0,
   "enableHandToolOnLoad": false,
   "enableWebGL": false,
   "pdfBugEnabled": false,
   "disableRange": false,
   "disableStream": false,
   "disableAutoFetch": false,
   "disableFontFace": false,
   "disableTextLayer": false,
   "useOnlyCssZoom": false,
   "externalLinkTarget": 0,
   "enhanceTextSelection": false,
   "renderer": "canvas",
   "renderInteractiveForms": false,
   "enablePrintAutoRotate": false,
   "disablePageLabels": false
  });
 }
 return defaultPreferences;
}
function cloneObj(obj) {
 var result = {};
 for (var i in obj) {
  if (Object.prototype.hasOwnProperty.call(obj, i)) {
   result[i] = obj[i];
  }
 }
 return result;
}
var Preferences = {
 prefs: null,
 isInitializedPromiseResolved: false,
 initializedPromise: null,
 initialize: function preferencesInitialize() {
  return this.initializedPromise = getDefaultPreferences().then(function (defaults) {
   Object.defineProperty(this, 'defaults', {
    value: Object.freeze(defaults),
    writable: false,
    enumerable: true,
    configurable: false
   });
   this.prefs = cloneObj(defaults);
   return this._readFromStorage(defaults);
  }.bind(this)).then(function (prefObj) {
   this.isInitializedPromiseResolved = true;
   if (prefObj) {
    this.prefs = prefObj;
   }
  }.bind(this));
 },
 _writeToStorage: function preferences_writeToStorage(prefObj) {
  return Promise.resolve();
 },
 _readFromStorage: function preferences_readFromStorage(prefObj) {
  return Promise.resolve();
 },
 reset: function preferencesReset() {
  return this.initializedPromise.then(function () {
   this.prefs = cloneObj(this.defaults);
   return this._writeToStorage(this.defaults);
  }.bind(this));
 },
 reload: function preferencesReload() {
  return this.initializedPromise.then(function () {
   this._readFromStorage(this.defaults).then(function (prefObj) {
    if (prefObj) {
     this.prefs = prefObj;
    }
   }.bind(this));
  }.bind(this));
 },
 set: function preferencesSet(name, value) {
  return this.initializedPromise.then(function () {
   if (this.defaults[name] === undefined) {
    throw new Error('preferencesSet: \'' + name + '\' is undefined.');
   } else if (value === undefined) {
    throw new Error('preferencesSet: no value is specified.');
   }
   var valueType = typeof value;
   var defaultType = typeof this.defaults[name];
   if (valueType !== defaultType) {
    if (valueType === 'number' && defaultType === 'string') {
     value = value.toString();
    } else {
     throw new Error('Preferences_set: \'' + value + '\' is a \"' + valueType + '\", expected \"' + defaultType + '\".');
    }
   } else {
    if (valueType === 'number' && (value | 0) !== value) {
     throw new Error('Preferences_set: \'' + value + '\' must be an \"integer\".');
    }
   }
   this.prefs[name] = value;
   return this._writeToStorage(this.prefs);
  }.bind(this));
 },
 get: function preferencesGet(name) {
  return this.initializedPromise.then(function () {
   var defaultValue = this.defaults[name];
   if (defaultValue === undefined) {
    throw new Error('preferencesGet: \'' + name + '\' is undefined.');
   } else {
    var prefValue = this.prefs[name];
    if (prefValue !== undefined) {
     return prefValue;
    }
   }
   return defaultValue;
  }.bind(this));
 }
};
Preferences._writeToStorage = function (prefObj) {
 return new Promise(function (resolve) {
  localStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj));
  resolve();
 });
};
Preferences._readFromStorage = function (prefObj) {
 return new Promise(function (resolve) {
  var readPrefs = JSON.parse(localStorage.getItem('pdfjs.preferences'));
  resolve(readPrefs);
 });
};
exports.Preferences = Preferences;