128 lines
3.9 KiB
JavaScript
128 lines
3.9 KiB
JavaScript
/* Copyright 2012 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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(function (root, factory) {
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if (typeof define === 'function' && define.amd) {
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define('pdfjs-web/view_history', ['exports'], factory);
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} else if (typeof exports !== 'undefined') {
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factory(exports);
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} else {
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factory((root.pdfjsWebViewHistory = {}));
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}
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}(this, function (exports) {
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var DEFAULT_VIEW_HISTORY_CACHE_SIZE = 20;
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/**
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* View History - This is a utility for saving various view parameters for
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* recently opened files.
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*
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* The way that the view parameters are stored depends on how PDF.js is built,
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* for 'gulp <flag>' the following cases exist:
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* - FIREFOX or MOZCENTRAL - uses sessionStorage.
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* - GENERIC or CHROME - uses localStorage, if it is available.
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*/
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var ViewHistory = (function ViewHistoryClosure() {
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function ViewHistory(fingerprint, cacheSize) {
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this.fingerprint = fingerprint;
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this.cacheSize = cacheSize || DEFAULT_VIEW_HISTORY_CACHE_SIZE;
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this.isInitializedPromiseResolved = false;
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this.initializedPromise =
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this._readFromStorage().then(function (databaseStr) {
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this.isInitializedPromiseResolved = true;
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var database = JSON.parse(databaseStr || '{}');
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if (!('files' in database)) {
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database.files = [];
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}
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if (database.files.length >= this.cacheSize) {
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database.files.shift();
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}
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var index;
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for (var i = 0, length = database.files.length; i < length; i++) {
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var branch = database.files[i];
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if (branch.fingerprint === this.fingerprint) {
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index = i;
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break;
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}
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}
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if (typeof index !== 'number') {
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index = database.files.push({fingerprint: this.fingerprint}) - 1;
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}
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this.file = database.files[index];
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this.database = database;
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}.bind(this));
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}
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ViewHistory.prototype = {
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_writeToStorage: function ViewHistory_writeToStorage() {
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return new Promise(function (resolve) {
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var databaseStr = JSON.stringify(this.database);
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if (typeof PDFJSDev !== 'undefined' &&
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PDFJSDev.test('FIREFOX || MOZCENTRAL')) {
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sessionStorage.setItem('pdfjsHistory', databaseStr);
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} else {
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localStorage.setItem('database', databaseStr);
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}
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resolve();
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}.bind(this));
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},
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_readFromStorage: function ViewHistory_readFromStorage() {
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return new Promise(function (resolve) {
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if (typeof PDFJSDev !== 'undefined' &&
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PDFJSDev.test('FIREFOX || MOZCENTRAL')) {
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resolve(sessionStorage.getItem('pdfjsHistory'));
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} else {
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resolve(localStorage.getItem('database'));
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}
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});
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},
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set: function ViewHistory_set(name, val) {
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if (!this.isInitializedPromiseResolved) {
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return;
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}
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this.file[name] = val;
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return this._writeToStorage();
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},
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setMultiple: function ViewHistory_setMultiple(properties) {
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if (!this.isInitializedPromiseResolved) {
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return;
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}
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for (var name in properties) {
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this.file[name] = properties[name];
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}
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return this._writeToStorage();
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},
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get: function ViewHistory_get(name, defaultValue) {
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if (!this.isInitializedPromiseResolved) {
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return defaultValue;
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}
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return this.file[name] || defaultValue;
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}
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};
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return ViewHistory;
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})();
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exports.ViewHistory = ViewHistory;
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}));
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