// History manager.
var HistoryManager = function() {
this.initialize();
};
HistoryManager.prototype = {
initialize: function() {
this.pollFrequency = 0.1; // Seconds.
this._currentLocation = this._getHash();
var historyManager = this;
if (Prototype.Browser.IE) {
this.addState = this._addStateIE;
var iframe = document.getElementById("_historyFrameIE");
if (iframe == null) {
//alert("HistoryManager: need IFRAME with ID '_historyFrameIE' in document.");
//return;
// Following does not always work:
document.write("");
//iframe = document.createElement("IFRAME");
//iframe.src = "javascript:''";
//iframe.style.position = "absolute";
//iframe.style.top = "-1000px";
//document.body.appendChild(iframe);
iframe = document.getElementById("_historyFrameIE");
}
this._iframe = iframe.contentWindow;
$justForIE = function(hash) {
historyManager._getHash = function() { return hash; }
historyManager._monitorDefault.call(historyManager);
location.hash = hash;
}
function waitForIframeLoad() {
if (historyManager._iframe && historyManager._iframe.document && historyManager._iframe.document.body) {
if (!historyManager._iframe.document.body.innerHTML) {
historyManager.addState(historyManager._currentLocation, true);
}
} else {
setTimeout(waitForIframeLoad, 50);
}
}
waitForIframeLoad();
}
else if (Prototype.Browser.WebKit && !window.xpath /* WebKit419 */) {
this._form = document.createElement("FORM");
this._form.method = "get";
document.body.appendChild(this._form);
this._historyCounter = history.length;
this._stateHistory = [];
this._stateHistory[history.length] = this._getHash();
this.addState = this._addStateSafari;
new PeriodicalExecuter(this._monitorSafari.bind(this), this.pollFrequency);
}
else if (Prototype.Browser.Opera) {
this.addState = this._addStateDefault;
Event.observe(window, "load", function() {
$justForOpera = function() {
historyManager._monitorDefault.call(historyManager);
}
var img = document.createElement("IMG");
img.src = "javascript:location.href='javascript:$justForOpera();';";
img.style.position = "absolute";
img.style.top = "-1000px";
document.body.appendChild(img);
}.bind(this));
}
else {
this.addState = this._addStateDefault;
new PeriodicalExecuter(this._monitorDefault.bind(this), this.pollFrequency);
}
},
getCurrentLocation: function() {
return this._currentLocation;
},
_getHash: function() {
return location.href.split('#')[1] || '';
},
_addStateIE: function(hash, override) {
if (this._currentLocation == hash && !override) {
return;
}
this._currentLocation = hash;
this._iframe.document.write('');
if (this.frameTitle != null) {
this._iframe.document.write("" + this.frameTitle + "");
}
this._iframe.document.write('Loaded');
this._iframe.document.close();
},
_getFrameStateIE: function() {
return this._iframe.document.body.hash;
},
_addStateSafari: function(hash) {
if (this._currentLocation == hash) return;
this._form.action = '#' + hash;
this._form.submit();
this._currentLocation = hash;
this._stateHistory[history.length] = this._getHash();
this._historyCounter = history.length;
},
_monitorSafari: function() {
if (history.length != this._historyCounter) {
this._historyCounter = history.length;
this._currentLocation = this._stateHistory[history.length];
this.fireEvent('onHistoryChange', [this._stateHistory[history.length]]);
}
},
_addStateDefault: function(hash) {
if (this._currentLocation == hash) return;
this._currentLocation = hash;
location.hash = '#' + hash;
},
_monitorDefault: function() {
var hash = this._getHash();
if (hash != this._currentLocation) {
this._currentLocation = hash;
this.fireEvent('onHistoryChange', hash);
}
},
addEvent: function(type, fn) {
this.listener = fn;
},
fireEvent: function(type, hash) {
if (this.listener != null) {
this.listener(hash);
}
}
};
var historyManager = new HistoryManager();