vitro/webapp/web/src/undo/browser.js

279 lines
9.8 KiB
JavaScript

/*
Copyright (c) 2004-2006, The Dojo Foundation
All Rights Reserved.
Licensed under the Academic Free License version 2.1 or above OR the
modified BSD license. For more information on Dojo licensing, see:
http://dojotoolkit.org/community/licensing.shtml
*/
dojo.provide("dojo.undo.browser");
dojo.require("dojo.io");
try{
if((!djConfig["preventBackButtonFix"])&&(!dojo.hostenv.post_load_)){
document.write("<iframe style='border: 0px; width: 1px; height: 1px; position: absolute; bottom: 0px; right: 0px; visibility: visible;' name='djhistory' id='djhistory' src='"+(dojo.hostenv.getBaseScriptUri()+'iframe_history.html')+"'></iframe>");
}
}catch(e){/* squelch */}
if(dojo.render.html.opera){
dojo.debug("Opera is not supported with dojo.undo.browser, so back/forward detection will not work.");
}
/* NOTES:
* Safari 1.2:
* back button "works" fine, however it's not possible to actually
* DETECT that you've moved backwards by inspecting window.location.
* Unless there is some other means of locating.
* FIXME: perhaps we can poll on history.length?
* Safari 2.0.3+ (and probably 1.3.2+):
* works fine, except when changeUrl is used. When changeUrl is used,
* Safari jumps all the way back to whatever page was shown before
* the page that uses dojo.undo.browser support.
* IE 5.5 SP2:
* back button behavior is macro. It does not move back to the
* previous hash value, but to the last full page load. This suggests
* that the iframe is the correct way to capture the back button in
* these cases.
* Don't test this page using local disk for MSIE. MSIE will not create
* a history list for iframe_history.html if served from a file: URL.
* The XML served back from the XHR tests will also not be properly
* created if served from local disk. Serve the test pages from a web
* server to test in that browser.
* IE 6.0:
* same behavior as IE 5.5 SP2
* Firefox 1.0:
* the back button will return us to the previous hash on the same
* page, thereby not requiring an iframe hack, although we do then
* need to run a timer to detect inter-page movement.
*/
dojo.undo.browser = {
initialHref: window.location.href,
initialHash: window.location.hash,
moveForward: false,
historyStack: [],
forwardStack: [],
historyIframe: null,
bookmarkAnchor: null,
locationTimer: null,
/**
* setInitialState sets the state object and back callback for the very first page that is loaded.
* It is recommended that you call this method as part of an event listener that is registered via
* dojo.addOnLoad().
*/
setInitialState: function(args){
this.initialState = {"url": this.initialHref, "kwArgs": args, "urlHash": this.initialHash};
},
//FIXME: Would like to support arbitrary back/forward jumps. Have to rework iframeLoaded among other things.
//FIXME: is there a slight race condition in moz using change URL with the timer check and when
// the hash gets set? I think I have seen a back/forward call in quick succession, but not consistent.
/**
* addToHistory takes one argument, and it is an object that defines the following functions:
* - To support getting back button notifications, the object argument should implement a
* function called either "back", "backButton", or "handle". The string "back" will be
* passed as the first and only argument to this callback.
* - To support getting forward button notifications, the object argument should implement a
* function called either "forward", "forwardButton", or "handle". The string "forward" will be
* passed as the first and only argument to this callback.
* - If you want the browser location string to change, define "changeUrl" on the object. If the
* value of "changeUrl" is true, then a unique number will be appended to the URL as a fragment
* identifier (http://some.domain.com/path#uniquenumber). If it is any other value that does
* not evaluate to false, that value will be used as the fragment identifier. For example,
* if changeUrl: 'page1', then the URL will look like: http://some.domain.com/path#page1
*
* Full example:
*
* dojo.undo.browser.addToHistory({
* back: function() { alert('back pressed'); },
* forward: function() { alert('forward pressed'); },
* changeUrl: true
* });
*/
addToHistory: function(args){
var hash = null;
if(!this.historyIframe){
this.historyIframe = window.frames["djhistory"];
}
if(!this.bookmarkAnchor){
this.bookmarkAnchor = document.createElement("a");
(document.body||document.getElementsByTagName("body")[0]).appendChild(this.bookmarkAnchor);
this.bookmarkAnchor.style.display = "none";
}
if((!args["changeUrl"])||(dojo.render.html.ie)){
var url = dojo.hostenv.getBaseScriptUri()+"iframe_history.html?"+(new Date()).getTime();
this.moveForward = true;
dojo.io.setIFrameSrc(this.historyIframe, url, false);
}
if(args["changeUrl"]){
this.changingUrl = true;
hash = "#"+ ((args["changeUrl"]!==true) ? args["changeUrl"] : (new Date()).getTime());
setTimeout("window.location.href = '"+hash+"'; dojo.undo.browser.changingUrl = false;", 1);
this.bookmarkAnchor.href = hash;
if(dojo.render.html.ie){
var oldCB = args["back"]||args["backButton"]||args["handle"];
//The function takes handleName as a parameter, in case the
//callback we are overriding was "handle". In that case,
//we will need to pass the handle name to handle.
var tcb = function(handleName){
if(window.location.hash != ""){
setTimeout("window.location.href = '"+hash+"';", 1);
}
//Use apply to set "this" to args, and to try to avoid memory leaks.
oldCB.apply(this, [handleName]);
}
//Set interceptor function in the right place.
if(args["back"]){
args.back = tcb;
}else if(args["backButton"]){
args.backButton = tcb;
}else if(args["handle"]){
args.handle = tcb;
}
//If addToHistory is called, then that means we prune the
//forward stack -- the user went back, then wanted to
//start a new forward path.
this.forwardStack = [];
var oldFW = args["forward"]||args["forwardButton"]||args["handle"];
//The function takes handleName as a parameter, in case the
//callback we are overriding was "handle". In that case,
//we will need to pass the handle name to handle.
var tfw = function(handleName){
if(window.location.hash != ""){
window.location.href = hash;
}
if(oldFW){ // we might not actually have one
//Use apply to set "this" to args, and to try to avoid memory leaks.
oldFW.apply(this, [handleName]);
}
}
//Set interceptor function in the right place.
if(args["forward"]){
args.forward = tfw;
}else if(args["forwardButton"]){
args.forwardButton = tfw;
}else if(args["handle"]){
args.handle = tfw;
}
}else if(dojo.render.html.moz){
// start the timer
if(!this.locationTimer){
this.locationTimer = setInterval("dojo.undo.browser.checkLocation();", 200);
}
}
}
this.historyStack.push({"url": url, "kwArgs": args, "urlHash": hash});
},
checkLocation: function(){
if (!this.changingUrl){
var hsl = this.historyStack.length;
if((window.location.hash == this.initialHash||window.location.href == this.initialHref)&&(hsl == 1)){
// FIXME: could this ever be a forward button?
// we can't clear it because we still need to check for forwards. Ugg.
// clearInterval(this.locationTimer);
this.handleBackButton();
return;
}
// first check to see if we could have gone forward. We always halt on
// a no-hash item.
if(this.forwardStack.length > 0){
if(this.forwardStack[this.forwardStack.length-1].urlHash == window.location.hash){
this.handleForwardButton();
return;
}
}
// ok, that didn't work, try someplace back in the history stack
if((hsl >= 2)&&(this.historyStack[hsl-2])){
if(this.historyStack[hsl-2].urlHash==window.location.hash){
this.handleBackButton();
return;
}
}
}
},
iframeLoaded: function(evt, ifrLoc){
if(!dojo.render.html.opera){
var query = this._getUrlQuery(ifrLoc.href);
if(query == null){
// alert("iframeLoaded");
// we hit the end of the history, so we should go back
if(this.historyStack.length == 1){
this.handleBackButton();
}
return;
}
if(this.moveForward){
// we were expecting it, so it's not either a forward or backward movement
this.moveForward = false;
return;
}
//Check the back stack first, since it is more likely.
//Note that only one step back or forward is supported.
if(this.historyStack.length >= 2 && query == this._getUrlQuery(this.historyStack[this.historyStack.length-2].url)){
this.handleBackButton();
}
else if(this.forwardStack.length > 0 && query == this._getUrlQuery(this.forwardStack[this.forwardStack.length-1].url)){
this.handleForwardButton();
}
}
},
handleBackButton: function(){
//The "current" page is always at the top of the history stack.
var current = this.historyStack.pop();
if(!current){ return; }
var last = this.historyStack[this.historyStack.length-1];
if(!last && this.historyStack.length == 0){
last = this.initialState;
}
if (last){
if(last.kwArgs["back"]){
last.kwArgs["back"]();
}else if(last.kwArgs["backButton"]){
last.kwArgs["backButton"]();
}else if(last.kwArgs["handle"]){
last.kwArgs.handle("back");
}
}
this.forwardStack.push(current);
},
handleForwardButton: function(){
var last = this.forwardStack.pop();
if(!last){ return; }
if(last.kwArgs["forward"]){
last.kwArgs.forward();
}else if(last.kwArgs["forwardButton"]){
last.kwArgs.forwardButton();
}else if(last.kwArgs["handle"]){
last.kwArgs.handle("forward");
}
this.historyStack.push(last);
},
_getUrlQuery: function(url){
var segments = url.split("?");
if (segments.length < 2){
return null;
}
else{
return segments[1];
}
}
}