diff --git a/web/pdf_history.js b/web/pdf_history.js index a2fe22edb..99f255329 100644 --- a/web/pdf_history.js +++ b/web/pdf_history.js @@ -75,38 +75,74 @@ var PDFHistory = (function () { 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); + return; + } - // 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 && + // If the state is not set, then the user tried to navigate to a + // different hash by manually editing the URL and pressing Enter, or by + // clicking on an in-page link (e.g. the "current view" link). + // Save the current view state to the browser history. + + // Note: In Firefox, history.null could also be null after an in-page + // navigation to the same URL, and without dispatching the popstate + // event: https://bugzilla.mozilla.org/show_bug.cgi?id=1183881 + + if (self.uid === 0) { + // Replace the previous state if it was not explicitly set. + 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(); + replacePreviousHistoryState(previousParams, function() { + updateHistoryWithCurrentHash(); + }); + } else { + updateHistoryWithCurrentHash(); } }, false); + + function updateHistoryWithCurrentHash() { + self.previousHash = window.location.hash.slice(1); + self._pushToHistory({hash: self.previousHash}, false, true); + self._updatePreviousBookmark(); + } + + function replacePreviousHistoryState(params, callback) { + // To modify the previous history entry, the following happens: + // 1. history.back() + // 2. _pushToHistory, which calls history.replaceState( ... ) + // 3. history.forward() + // Because a navigation via the history API does not immediately update + // the history state, the popstate event is used for synchronization. + self.historyUnlocked = false; + + // Suppress the hashchange event to avoid side effects caused by + // navigating back and forward. + self.allowHashChange = false; + window.addEventListener('popstate', rewriteHistoryAfterBack); + history.back(); + + function rewriteHistoryAfterBack() { + window.removeEventListener('popstate', rewriteHistoryAfterBack); + window.addEventListener('popstate', rewriteHistoryAfterForward); + self._pushToHistory(params, false, true); + history.forward(); + } + function rewriteHistoryAfterForward() { + window.removeEventListener('popstate', rewriteHistoryAfterForward); + self.allowHashChange = true; + self.historyUnlocked = true; + callback(); + } + } + function pdfHistoryBeforeUnload() { var previousParams = self._getPreviousParams(null, true); if (previousParams) { @@ -178,19 +214,7 @@ var PDFHistory = (function () { 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; + return this.allowHashChange; }, _updatePreviousBookmark: function pdfHistory_updatePreviousBookmark() {