var cssdropdown = {
disappeardelay: 250,
disablemenuclick: false,
enableswipe: 1,
enableiframeshim: 1,
dropmenuobj: null,
ie: document.all,
firefox: document.getElementById && !document.all,
swipetimer: undefined,
bottomclip: 0,
getposOffset: function(what, offsettype) {
var totaloffset = (offsettype == "left") ? what.offsetLeft: what.offsetTop;
var parentEl = what.offsetParent;
while (parentEl != null) {
totaloffset = (offsettype == "left") ? totaloffset + parentEl.offsetLeft: totaloffset + parentEl.offsetTop;
parentEl = parentEl.offsetParent;
}
return totaloffset;
},
swipeeffect: function() {
if (this.bottomclip < parseInt(this.dropmenuobj.offsetHeight)) {
this.bottomclip += 10 + (this.bottomclip / 10);
this.dropmenuobj.style.clip = "rect(0 auto " + this.bottomclip + "px 0)";
} else return;
this.swipetimer = setTimeout("cssdropdown.swipeeffect()", 10);
},
//隱藏或者顯示二級菜單
showhide: function(obj, e) {
if (this.ie || this.firefox) this.dropmenuobj.style.left = this.dropmenuobj.style.top = "-500px";
if (e.type == "click" && obj.visibility == hidden || e.type == "mouseover") {
if (this.enableswipe == 1) {
if (typeof this.swipetimer != "undefined") clearTimeout(this.swipetimer);
obj.clip = "rect(0 auto 0 0)";
this.bottomclip = 0;
this.swipeeffect();
}
obj.visibility = "visible";
} else if (e.type == "click") obj.visibility = "hidden";
},
iecompattest: function() {
return (document.compatMode && document.compatMode != "BackCompat") ? document.documentElement: document.body;
},
clearbrowseredge: function(obj, whichedge) {
var edgeoffset = 0;
if (whichedge == "rightedge") {
var windowedge = this.ie && !window.opera ? this.iecompattest().scrollLeft + this.iecompattest().clientWidth - 15 : window.pageXOffset + window.innerWidth - 15;
this.dropmenuobj.contentmeasure = this.dropmenuobj.offsetWidth;
if (windowedge - this.dropmenuobj.x < this.dropmenuobj.contentmeasure) edgeoffset = this.dropmenuobj.contentmeasure - obj.offsetWidth;
} else {
var topedge = this.ie && !window.opera ? this.iecompattest().scrollTop: window.pageYOffset;
var windowedge = this.ie && !window.opera ? this.iecompattest().scrollTop + this.iecompattest().clientHeight - 15 : window.pageYOffset + window.innerHeight - 18;
this.dropmenuobj.contentmeasure = this.dropmenuobj.offsetHeight;
if (windowedge - this.dropmenuobj.y < this.dropmenuobj.contentmeasure) {
edgeoffset = this.dropmenuobj.contentmeasure + obj.offsetHeight;
if ((this.dropmenuobj.y - topedge) < this.dropmenuobj.contentmeasure) edgeoffset = this.dropmenuobj.y + obj.offsetHeight - topedge;
}
}
return edgeoffset;
},
//鼠標移動到一級菜單上執(zhí)行
dropit: function(obj, e, dropmenuID) {
//隱藏上次顯示的二級菜單
if (this.dropmenuobj != null) this.dropmenuobj.style.visibility = "hidden";
this.clearhidemenu();
if (this.ie || this.firefox) {
var me = this;
//一級菜單鼠標離開事件
obj.onmouseout = function() {
cssdropdown.delayhidemenu();
};
//一級菜單鼠標點擊事件
obj.onclick = function() {
return ! cssdropdown.disablemenuclick
};
if (!dropmenuID) {
return;
}
this.dropmenuobj = document.getElementById(dropmenuID);
if (!this.dropmenuobj) return;
//為二級菜單綁定鼠標移動到事件
this.dropmenuobj.onmouseover = function() {
//移除從一級菜單離開時觸發(fā)的方法，防止誤執(zhí)行
cssdropdown.clearhidemenu();
}
//為二級菜單綁定鼠標離開事件
this.dropmenuobj.onmouseout = function(e) {
cssdropdown.dynamichide(e);
}
//為二級菜單綁定鼠標點擊事件
this.dropmenuobj.onclick = function() {
cssdropdown.delayhidemenu();
}
this.showhide(this.dropmenuobj.style, e);
//調整二級菜單位置，以免位置錯亂
this.dropmenuobj.x = this.getposOffset(obj, "left");
this.dropmenuobj.y = this.getposOffset(obj, "top");
this.dropmenuobj.style.left = this.dropmenuobj.x - this.clearbrowseredge(obj, "rightedge") + "px";
this.dropmenuobj.style.top = this.dropmenuobj.y - this.clearbrowseredge(obj, "bottomedge") + obj.offsetHeight + 1 + "px";
this.positionshim();
}
},
positionshim: function() {
if (this.enableiframeshim && typeof this.shimobject != "undefined") {
if (this.dropmenuobj.style.visibility == "visible") {
this.shimobject.style.width = this.dropmenuobj.offsetWidth + "px";
this.shimobject.style.height = this.dropmenuobj.offsetHeight + "px";
this.shimobject.style.left = this.dropmenuobj.style.left;
this.shimobject.style.top = this.dropmenuobj.style.top;
}
this.shimobject.style.display = (this.dropmenuobj.style.visibility == "visible") ? "block": "none";
}
},
hideshim: function() {
if (this.enableiframeshim && typeof this.shimobject != "undefined") this.shimobject.style.display = 'none';
},
contains_firefox: function(a, b) {
while (b.parentNode) if ((b = b.parentNode) == a) return true;
return false;
},
//隱藏二級菜單，兼容性處理
dynamichide: function(e) {
var evtobj = window.event ? window.event: e;
//確認是鼠標離開事件，避免誤觸發(fā)
if (this.ie && !this.dropmenuobj.contains(evtobj.toElement)) this.delayhidemenu();
else if (this.firefox && e.currentTarget != evtobj.relatedTarget && !this.contains_firefox(evtobj.currentTarget, evtobj.relatedTarget)) this.delayhidemenu();
},
//鼠標點擊菜單，或者離開菜單時執(zhí)行
delayhidemenu: function() {
this.delayhide = setTimeout(function() {
cssdropdown.dropmenuobj.style.visibility = 'hidden';
cssdropdown.hideshim();
cssdropdown.showAlways();
},
this.disappeardelay);
},
//移除定時方法
clearhidemenu: function() {
if (this.delayhide != "undefined") clearTimeout(this.delayhide);
},
//顯示默認被選中的一級菜單
showAlways: function() {
if (this.always) {
this.always.onmouseover({
type: "mouseover"
});
}
},
//初始化
startchrome: function() {
for (var ids = 0; ids < arguments.length; ids++) {
var menuitems = document.getElementById(arguments[ids]).getElementsByTagName("a");
for (var i = 0; i < menuitems.length; i++) {
var relvalue = menuitems[i].getAttribute("rel");
//綁定鼠標移動到事件
menuitems[i].onmouseover = function(e) {
var event = typeof e != "undefined" ? e: window.event;
cssdropdown.dropit(this, event, this.getAttribute("rel"));
};
//顯示默認被選中的一級菜單
if (!this.always && menuitems[i].parentNode.getAttribute("class") == "navselect") {
this.always = menuitems[i];
this.showAlways();
}
}
}
if (window.createPopup && !window.XmlHttpRequest) {
document.write('<IFRAME id="iframeshim" src="" style="display: none; left: 0; top: 0; z-index: 90; position: absolute; filter: progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)" frameBorder="0" scrolling="no"></IFRAME>');
this.shimobject = document.getElementById("iframeshim");
}
}
}