comunic/3rdparty/pdf.js/web/pdf_history.js
2016-11-19 12:08:12 +01:00

406 lines
14 KiB
JavaScript
Executable File

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* Copyright 2012 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 PDFHistory = (function () {
function PDFHistory(options) {
this.linkService = options.linkService;
this.initialized = false;
this.initialDestination = null;
this.initialBookmark = null;
}
PDFHistory.prototype = {
/**
* @param {string} fingerprint
* @param {IPDFLinkService} linkService
*/
initialize: function pdfHistoryInitialize(fingerprint) {
this.initialized = true;
this.reInitialized = false;
this.allowHashChange = true;
this.historyUnlocked = true;
this.isViewerInPresentationMode = false;
this.previousHash = window.location.hash.substring(1);
this.currentBookmark = '';
this.currentPage = 0;
this.updatePreviousBookmark = false;
this.previousBookmark = '';
this.previousPage = 0;
this.nextHashParam = '';
this.fingerprint = fingerprint;
this.currentUid = this.uid = 0;
this.current = {};
var state = window.history.state;
if (this._isStateObjectDefined(state)) {
// This corresponds to navigating back to the document
// from another page in the browser history.
if (state.target.dest) {
this.initialDestination = state.target.dest;
} else {
this.initialBookmark = state.target.hash;
}
this.currentUid = state.uid;
this.uid = state.uid + 1;
this.current = state.target;
} else {
// This corresponds to the loading of a new document.
if (state && state.fingerprint &&
this.fingerprint !== state.fingerprint) {
// Reinitialize the browsing history when a new document
// is opened in the web viewer.
this.reInitialized = true;
}
this._pushOrReplaceState({fingerprint: this.fingerprint}, true);
}
var self = this;
window.addEventListener('popstate', function pdfHistoryPopstate(evt) {
evt.preventDefault();
evt.stopPropagation();
if (!self.historyUnlocked) {
return;
}
if (evt.state) {
// Move back/forward in the history.
self._goTo(evt.state);
} else {
// Handle the user modifying the hash of a loaded document.
self.previousHash = window.location.hash.substring(1);
// If the history is empty when the hash changes,
// update the previous entry in the browser history.
if (self.uid === 0) {
var previousParams = (self.previousHash && self.currentBookmark &&
self.previousHash !== self.currentBookmark) ?
{hash: self.currentBookmark, page: self.currentPage} :
{page: 1};
self.historyUnlocked = false;
self.allowHashChange = false;
window.history.back();
self._pushToHistory(previousParams, false, true);
window.history.forward();
self.historyUnlocked = true;
}
self._pushToHistory({hash: self.previousHash}, false, true);
self._updatePreviousBookmark();
}
}, false);
function pdfHistoryBeforeUnload() {
var previousParams = self._getPreviousParams(null, true);
if (previousParams) {
var replacePrevious = (!self.current.dest &&
self.current.hash !== self.previousHash);
self._pushToHistory(previousParams, false, replacePrevious);
self._updatePreviousBookmark();
}
// Remove the event listener when navigating away from the document,
// since 'beforeunload' prevents Firefox from caching the document.
window.removeEventListener('beforeunload', pdfHistoryBeforeUnload,
false);
}
window.addEventListener('beforeunload', pdfHistoryBeforeUnload, false);
window.addEventListener('pageshow', function pdfHistoryPageShow(evt) {
// If the entire viewer (including the PDF file) is cached in
// the browser, we need to reattach the 'beforeunload' event listener
// since the 'DOMContentLoaded' event is not fired on 'pageshow'.
window.addEventListener('beforeunload', pdfHistoryBeforeUnload, false);
}, false);
window.addEventListener('presentationmodechanged', function(e) {
self.isViewerInPresentationMode = !!e.detail.active;
});
},
clearHistoryState: function pdfHistory_clearHistoryState() {
this._pushOrReplaceState(null, true);
},
_isStateObjectDefined: function pdfHistory_isStateObjectDefined(state) {
return (state && state.uid >= 0 &&
state.fingerprint && this.fingerprint === state.fingerprint &&
state.target && state.target.hash) ? true : false;
},
_pushOrReplaceState: function pdfHistory_pushOrReplaceState(stateObj,
replace) {
//#if CHROME
// history.state.chromecomState is managed by chromecom.js.
if (window.history.state && 'chromecomState' in window.history.state) {
stateObj = stateObj || {};
stateObj.chromecomState = window.history.state.chromecomState;
}
//#endif
if (replace) {
//#if (GENERIC || CHROME)
window.history.replaceState(stateObj, '', document.URL);
//#else
// window.history.replaceState(stateObj, '');
//#endif
} else {
//#if (GENERIC || CHROME)
window.history.pushState(stateObj, '', document.URL);
//#else
// window.history.pushState(stateObj, '');
//#endif
//#if CHROME
// if (top === window) {
// chrome.runtime.sendMessage('showPageAction');
// }
//#endif
}
},
get isHashChangeUnlocked() {
if (!this.initialized) {
return true;
}
// If the current hash changes when moving back/forward in the history,
// this will trigger a 'popstate' event *as well* as a 'hashchange' event.
// Since the hash generally won't correspond to the exact the position
// stored in the history's state object, triggering the 'hashchange' event
// can thus corrupt the browser history.
//
// When the hash changes during a 'popstate' event, we *only* prevent the
// first 'hashchange' event and immediately reset allowHashChange.
// If it is not reset, the user would not be able to change the hash.
var temp = this.allowHashChange;
this.allowHashChange = true;
return temp;
},
_updatePreviousBookmark: function pdfHistory_updatePreviousBookmark() {
if (this.updatePreviousBookmark &&
this.currentBookmark && this.currentPage) {
this.previousBookmark = this.currentBookmark;
this.previousPage = this.currentPage;
this.updatePreviousBookmark = false;
}
},
updateCurrentBookmark: function pdfHistoryUpdateCurrentBookmark(bookmark,
pageNum) {
if (this.initialized) {
this.currentBookmark = bookmark.substring(1);
this.currentPage = pageNum | 0;
this._updatePreviousBookmark();
}
},
updateNextHashParam: function pdfHistoryUpdateNextHashParam(param) {
if (this.initialized) {
this.nextHashParam = param;
}
},
push: function pdfHistoryPush(params, isInitialBookmark) {
if (!(this.initialized && this.historyUnlocked)) {
return;
}
if (params.dest && !params.hash) {
params.hash = (this.current.hash && this.current.dest &&
this.current.dest === params.dest) ?
this.current.hash :
this.linkService.getDestinationHash(params.dest).split('#')[1];
}
if (params.page) {
params.page |= 0;
}
if (isInitialBookmark) {
var target = window.history.state.target;
if (!target) {
// Invoked when the user specifies an initial bookmark,
// thus setting initialBookmark, when the document is loaded.
this._pushToHistory(params, false);
this.previousHash = window.location.hash.substring(1);
}
this.updatePreviousBookmark = this.nextHashParam ? false : true;
if (target) {
// If the current document is reloaded,
// avoid creating duplicate entries in the history.
this._updatePreviousBookmark();
}
return;
}
if (this.nextHashParam) {
if (this.nextHashParam === params.hash) {
this.nextHashParam = null;
this.updatePreviousBookmark = true;
return;
} else {
this.nextHashParam = null;
}
}
if (params.hash) {
if (this.current.hash) {
if (this.current.hash !== params.hash) {
this._pushToHistory(params, true);
} else {
if (!this.current.page && params.page) {
this._pushToHistory(params, false, true);
}
this.updatePreviousBookmark = true;
}
} else {
this._pushToHistory(params, true);
}
} else if (this.current.page && params.page &&
this.current.page !== params.page) {
this._pushToHistory(params, true);
}
},
_getPreviousParams: function pdfHistory_getPreviousParams(onlyCheckPage,
beforeUnload) {
if (!(this.currentBookmark && this.currentPage)) {
return null;
} else if (this.updatePreviousBookmark) {
this.updatePreviousBookmark = false;
}
if (this.uid > 0 && !(this.previousBookmark && this.previousPage)) {
// Prevent the history from getting stuck in the current state,
// effectively preventing the user from going back/forward in
// the history.
//
// This happens if the current position in the document didn't change
// when the history was previously updated. The reasons for this are
// either:
// 1. The current zoom value is such that the document does not need to,
// or cannot, be scrolled to display the destination.
// 2. The previous destination is broken, and doesn't actally point to a
// position within the document.
// (This is either due to a bad PDF generator, or the user making a
// mistake when entering a destination in the hash parameters.)
return null;
}
if ((!this.current.dest && !onlyCheckPage) || beforeUnload) {
if (this.previousBookmark === this.currentBookmark) {
return null;
}
} else if (this.current.page || onlyCheckPage) {
if (this.previousPage === this.currentPage) {
return null;
}
} else {
return null;
}
var params = {hash: this.currentBookmark, page: this.currentPage};
if (this.isViewerInPresentationMode) {
params.hash = null;
}
return params;
},
_stateObj: function pdfHistory_stateObj(params) {
return {fingerprint: this.fingerprint, uid: this.uid, target: params};
},
_pushToHistory: function pdfHistory_pushToHistory(params,
addPrevious, overwrite) {
if (!this.initialized) {
return;
}
if (!params.hash && params.page) {
params.hash = ('page=' + params.page);
}
if (addPrevious && !overwrite) {
var previousParams = this._getPreviousParams();
if (previousParams) {
var replacePrevious = (!this.current.dest &&
this.current.hash !== this.previousHash);
this._pushToHistory(previousParams, false, replacePrevious);
}
}
this._pushOrReplaceState(this._stateObj(params),
(overwrite || this.uid === 0));
this.currentUid = this.uid++;
this.current = params;
this.updatePreviousBookmark = true;
},
_goTo: function pdfHistory_goTo(state) {
if (!(this.initialized && this.historyUnlocked &&
this._isStateObjectDefined(state))) {
return;
}
if (!this.reInitialized && state.uid < this.currentUid) {
var previousParams = this._getPreviousParams(true);
if (previousParams) {
this._pushToHistory(this.current, false);
this._pushToHistory(previousParams, false);
this.currentUid = state.uid;
window.history.back();
return;
}
}
this.historyUnlocked = false;
if (state.target.dest) {
this.linkService.navigateTo(state.target.dest);
} else {
this.linkService.setHash(state.target.hash);
}
this.currentUid = state.uid;
if (state.uid > this.uid) {
this.uid = state.uid;
}
this.current = state.target;
this.updatePreviousBookmark = true;
var currentHash = window.location.hash.substring(1);
if (this.previousHash !== currentHash) {
this.allowHashChange = false;
}
this.previousHash = currentHash;
this.historyUnlocked = true;
},
back: function pdfHistoryBack() {
this.go(-1);
},
forward: function pdfHistoryForward() {
this.go(1);
},
go: function pdfHistoryGo(direction) {
if (this.initialized && this.historyUnlocked) {
var state = window.history.state;
if (direction === -1 && state && state.uid > 0) {
window.history.back();
} else if (direction === 1 && state && state.uid < (this.uid - 1)) {
window.history.forward();
}
}
}
};
return PDFHistory;
})();