Fading scroller

March 23rd, 2008 by ducmanh Leave a reply »

Dưới đây mình xin giới thiệu đến các bạn cách làm một Scroll updown tự động show ra các message như ví dụ ở dưới đậy Ví dụ:

>>  Xem Demo tại đây

 Cách làm như sau Bước 1 Trước hết bạn copy toàn bộ code dưới đây vào phần <head> của trang web.

Code:

<style type="text/css">
/*Example CSS for the two demo scrollers*/
#pscroller1{
width: 200px;
height: 100px;
border: 1px solid black;
padding: 5px;
background-color: lightyellow;
}

#pscroller2{
width: 350px;
height: 20px;
border: 1px solid black;
padding: 3px;
}

#pscroller2 a{
text-decoration: none;
}

.someclass{ //class to apply to your scroller(s) if desired
}

</style>

<script type="text/javascript">

/*Example message arrays for the two demo scrollers*/

var pausecontent=new Array()
pausecontent[0]=’<a href="http://www.mangraovat.net">Mangraovat.net</a><br />Ket noi ban voi ca the gioi!’
pausecontent[1]=’<a href="http://www.hrvn.net">hrvn.net</a>’

pausecontent[2]=’<a href="http://www.cssdrive.com" target="_new">CSS Drive</a><br />Categorized CSS gallery and examples.’

var pausecontent2=new Array()
pausecontent2[0]=’<a href="http://www.news.com">News.com: Technology and business reports</a>’
pausecontent2[1]=’<a href="http://www.cnn.com">CNN: Headline and breaking news 24/7</a>’
pausecontent2[2]=’<a href="http://news.bbc.co.uk">BBC News: UK and international news</a>’

</script>

<script type="text/javascript">

/***********************************************

***********************************************/

function pausescroller(content, divId, divClass, delay){
this.content=content //message array content
this.tickerid=divId //ID of ticker div to display information
this.delay=delay //Delay between msg change, in miliseconds.
this.mouseoverBol=0 //Boolean to indicate whether mouse is currently over scroller (and pause it if it is)
this.hiddendivpointer=1 //index of message array for hidden div
document.write(’<div id="’+divId+’" class="’+divClass+’" style="position: relative; overflow: hidden"><div class="innerDiv" style="position: absolute; width: 100%" id="’+divId+’1">’+content[0]+’</div><div class="innerDiv" style="position: absolute; width: 100%; visibility: hidden" id="’+divId+’2">’+content[1]+’</div></div>’)
var scrollerinstance=this
if (window.addEventListener) //run onload in DOM2 browsers
window.addEventListener("load", function(){scrollerinstance.initialize()}, false)
else if (window.attachEvent) //run onload in IE5.5+
window.attachEvent("onload", function(){scrollerinstance.initialize()})
else if (document.getElementById) //if legacy DOM browsers, just start scroller after 0.5 sec
setTimeout(function(){scrollerinstance.initialize()}, 500)
}

// ——————————————————————-
// initialize()- Initialize scroller method.
// -Get div objects, set initial positions, start up down animation
// ——————————————————————-

pausescroller.prototype.initialize=function(){
this.tickerdiv=document.getElementById(this.tickerid)
this.visiblediv=document.getElementById(this.tickerid+"1")
this.hiddendiv=document.getElementById(this.tickerid+"2")
this.visibledivtop=parseInt(pausescroller.getCSSpadding(this.tickerdiv))
//set width of inner DIVs to outer DIV’s width minus padding (padding assumed to be top padding x 2)
this.visiblediv.style.width=this.hiddendiv.style.width=this.tickerdiv.offsetWidth-(this.visibledivtop*2)+"px"
this.getinline(this.visiblediv, this.hiddendiv)
this.hiddendiv.style.visibility="visible"
var scrollerinstance=this
document.getElementById(this.tickerid).onmouseover=function(){scrollerinstance.mouseoverBol=1}
document.getElementById(this.tickerid).onmouseout=function(){scrollerinstance.mouseoverBol=0}
if (window.attachEvent) //Clean up loose references in IE
window.attachEvent("onunload", function(){scrollerinstance.tickerdiv.onmouseover=scrollerinstance.tickerdiv.onmouseout=null})
setTimeout(function(){scrollerinstance.animateup()}, this.delay)
}

// ——————————————————————-
// animateup()- Move the two inner divs of the scroller up and in sync
// ——————————————————————-

pausescroller.prototype.animateup=function(){
var scrollerinstance=this
if (parseInt(this.hiddendiv.style.top)>(this.visibledivtop+5)){
this.visiblediv.style.top=parseInt(this.visiblediv.style.top)-5+"px"
this.hiddendiv.style.top=parseInt(this.hiddendiv.style.top)-5+"px"
setTimeout(function(){scrollerinstance.animateup()}, 50)
}
else{
this.getinline(this.hiddendiv, this.visiblediv)
this.swapdivs()
setTimeout(function(){scrollerinstance.setmessage()}, this.delay)
}
}

// ——————————————————————-
// swapdivs()- Swap between which is the visible and which is the hidden div
// ——————————————————————-

pausescroller.prototype.swapdivs=function(){
var tempcontainer=this.visiblediv
this.visiblediv=this.hiddendiv
this.hiddendiv=tempcontainer
}

pausescroller.prototype.getinline=function(div1, div2){
div1.style.top=this.visibledivtop+"px"
div2.style.top=Math.max(div1.parentNode.offsetHeight, div1.offsetHeight)+"px"
}

// ——————————————————————-
// setmessage()- Populate the hidden div with the next message before it’s visible
// ——————————————————————-

pausescroller.prototype.setmessage=function(){
var scrollerinstance=this
if (this.mouseoverBol==1) //if mouse is currently over scoller, do nothing (pause it)
setTimeout(function(){scrollerinstance.setmessage()}, 100)
else{
var i=this.hiddendivpointer
var ceiling=this.content.length
this.hiddendivpointer=(i+1>ceiling-1)? 0 : i+1
this.hiddendiv.innerHTML=this.content[this.hiddendivpointer]
this.animateup()
}
}

pausescroller.getCSSpadding=function(tickerobj){ //get CSS padding value, if any
if (tickerobj.currentStyle)
return tickerobj.currentStyle["paddingTop"]
else if (window.getComputedStyle) //if DOM2
return window.getComputedStyle(tickerobj, "").getPropertyValue("padding-top")
else
return 0
}
</script>

Bước 2: Bạn copy đoạn mã sau vào chỗ muốn hiển thị pausing up-down scroller.

Code:

<script type="text/javascript">
//new pausescroller(name_of_message_array, CSS_ID, CSS_classname, pause_in_miliseconds)
new pausescroller(pausecontent, "pscroller1", "someclass", 3000)
document.write("<br />")
new pausescroller(pausecontent2, "pscroller2", "someclass", 2000)
</script>

 

Các nội dung trên mình để Demo. Bạn thay đổi lại cho phù hợp với trang web của ban.
                                                                        

                                    Chúc các bạn thành công!
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1 comment

  1. Daniel says:

    I read similar article also named g scroller : BLOG THIẾT KẾ WEB - Chuyên trang dạy,học,hướng dẫn,chia sẻ tài liệu thiết kế website, and it was completely different. Personally, I agree with you more, because this article makes a little bit more sense for me

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