ＪＡＶＡＳＣＲＩＰＴ 滚动字幕（支持添加多个)

注: 在日文系统编写,所以用了我这乱七八糟的英文注释。Sorry!

JS文件:

//***********************************************************************************
//         JavaScript HTML DIV scroll bar controler
//
//                                 by [email protected] 2005.06.15
//
//          useage:
//                 create DIV scrollbar
//                 scroll directions: scroll up/ down/ left/ right
//          setp 1:
//                   in HTML document, add a div tag and give "id" attribute
//          setp 2:
//                   include this file into your HTML and etc document
//                          use "<script>" tag include src attribute
//          setp 3:
//                   write your script
//                   exmple:
//                        var scrollBarControl = new scrollBar();
//                        scrollBarControl.addBar("myBarID", 100, 100, 50, "down");
//                        scrollBarcontrol.createScrollBars();
//           finally:
//                   save your HTML document and test it.
//
//----------------------------------------------------------------------------------
//         method:
//                 scrollBar()
//                                         scrollBarControl class constrction
//                                                    without parameters
//                 addBar(barID, width, height, interval, direction)
//                                         add user bar define
//                                 parameters:
//                                         barID (Required)              String <DIV ID="xxx"> the id tag
//                                         width (Optional)               Integer that specifies the bar's width
//                                         height (Optional)              Integer that specifies the bar's height
//                                         interval (Optional)             Integer that specifies the number of milliseconds.
//                                         direction (Optional)            String that specifies the scroll direction
//
//***********************************************************************************

var __scrollBarControl = null;

function innerBarProp(barID, width, height, interval, direction)
{
 this.barID = barID;
 this.width = width;
 this.height = height;
 this.interval = interval;
 this.direction = direction;
 this.stopScroll = false;
 this.maxValue = 0;
 this.preValue = 0;
}

function scrollBar()
{
 this.barsArray = new Array();
 //save current object
 __scrollBarControl = this;
}

//////////////////////////////////////////////////////////////////
// add scrollbar to bar list and set properties
// parameters:
//     barID: HTML's tag <DIV>'s id property
//              (for js access the DIV object)
//     width: define the scrollbar's width
//     height: define the scrollbar's height
//     interval: define the scroll speed
//               ( scroll up/down per XX millinSecond )
//     direction: scroll direction's defined
//               "up"
//               "down"
//               "left"
//               "right"
//////////////////////////////////////////////////////////////////
scrollBar.prototype.addBar = function(barID, width, height, interval, direction)
{
 //check parameters
 var paraCount = arguments.length;
 if ( paraCount < 1 )
 {
  alert("parameters count incorect!");
  return;
  //throw "parameters count inccorect!";
 }
 
 //width's default value
 if ( typeof( width ) == "undefined" )
 {
  var width = 100;
 }
 
 //height's default value
 if ( typeof( height ) == "undefined" )
 {
  var height = 100;
 }
 
 //interval's default value
 if ( typeof( interval ) == "undefined" )
 {
  var interval = 1000;
 }
 
 //direction's default value
 if ( typeof( direction ) == "undefined" )
 {
  var direction = "up";
 }
 
 //create scrollbar's inner properties
 var barProp = new innerBarProp(barID, width, height, interval, direction);
 var barCount = this.barsArray.length;
 this.barsArray[barCount] = barProp;
}

scrollBar.prototype.createScrollBars = function()
{
 //get bar's count
 var barCount = this.barsArray.length;
 //if no bar add to scrollControl do nothing
 if ( barCount == 0 )
 {
  return;
 }
 
 //init scroll bars
 for ( var i=0; i<barCount; i++ )
 {
  var objBarID = this.barsArray[i].barID;
  //if typeof objBarID is object
  // that's meaning it inited
  //if typeof objBarID is string
  // init that scroll bar
  if ( typeof( objBarID ) == "string" )
  {
   //get scroll <DIV> object
   var objBar = document.getElementById( objBarID );
   if (objBar == null)
   {
    //objBarID is not exist
    if ( document.readyState == "complete" || document.readyState == "loaded" )
    {
     //the objBarID not exists in current document
     //throw "the objBarID is not exists.";
     alert("ScrollBar[" + objBarID + "]: not exist!");
     return;
    }
    else
    {
     //wait for document to load objBarID
     window.setTimeout("__scrollBarControl.createScrollBars()",50);
     //exit processing..........
     //and wait next time callbak
     return;
    }
   }
   
   //update barID
   this.barsArray[i].barID = objBar;
  }
 }
 
 for ( var i=0; i<barCount; i++ )
 {
  this.innerInitBar(i);
 }
}

scrollBar.prototype.innerInitBar = function (index)
{ 
 //get properties
 var barID = this.barsArray[index].barID;
 var width = this.barsArray[index].width;
 var height = this.barsArray[index].height;
 var interval = this.barsArray[index].interval;
 var direction = this.barsArray[index].direction;
 var maxValue = 0;
 
 //set scrollBar's properties
 with(barID)
 {
  style.width = width;
  style.height = height;
  noWrap=true;

  switch( direction )
  {
   case "up":
    maxValue = Math.max(scrollHeight, height);
    style.overflowX = "visible";
    style.overflowY = "hidden";
    var barHtml = innerHTML;
    var newHtml = "<table border='0' cellspacing='0' cellpadding='0'>/n";
    newHtml += "  <tr>/n";
    newHtml += "    <td height='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "  </tr>/n";
    newHtml += "  <tr>/n";
    newHtml += "    <td height='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "  </tr>/n";
    newHtml += "</table>/n";
    innerHTML = newHtml;
    break;
   case "down":
    maxValue = Math.max(scrollHeight, height);
    style.overflowX = "visible";
    style.overflowY = "hidden";
    var barHtml = innerHTML;
    var newHtml = "<table border='0' cellspacing='0' cellpadding='0'>/n";
    newHtml += "  <tr>/n";
    newHtml += "    <td height='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "  </tr>/n";
    newHtml += "  <tr>/n";
    newHtml += "    <td height='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "  </tr>/n";
    newHtml += "</table>/n";
    innerHTML = newHtml;
    scrollTop = maxValue;
    break;
   case "left":
    maxValue = Math.max(scrollWidth, width);
    style.overflowX = "hidden";
    style.overflowY = "visible";
    var barHtml = barID.innerHTML;
    var newHtml = "<table border='0' cellspacing='0' cellpadding='0' width='" + (maxValue * 2 ) + "'>/n";
    newHtml += "  <tr>/n";
    newHtml += "    <td width='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "    <td width='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "  </tr>/n";
    newHtml += "</table>/n";
    innerHTML = newHtml;
    break;
   case "right":
    maxValue = Math.max(scrollWidth, width);
    style.overflowX = "hidden";
    style.overflowY = "visible";
    var barHtml = innerHTML;
    var newHtml = "<table border='0' cellspacing='0' cellpadding='0' width='" + (maxValue * 2 ) + "'>/n";
    newHtml += "  <tr>/n";
    newHtml += "    <td width='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "    <td width='" + maxValue + "' valign='top'>/n";
    newHtml += barHtml + "/n";
    newHtml += "    </td>/n";
    newHtml += "  </tr>/n";
    newHtml += "</table>/n";
    innerHTML = newHtml;
    scrollLeft = maxValue;
    break;
   default:
    //throw "direction is inccorect!";
    alert("ScrollBar[" + id + "]: direction is incorect!");
    return;
  }
  
  //set mouse events
  onmouseover = new Function("__scrollBarControl.mouseEvt(" + index + ",true);");
  onmouseout = new Function("__scrollBarControl.mouseEvt(" + index + ",false);");
  window.setInterval("__scrollBarControl.scroll(" + index + ");",interval);
  
  //save maxValue
  this.barsArray[index].maxValue = maxValue;
 }
}

scrollBar.prototype.mouseEvt = function(index, stop)
{
 this.barsArray[index].stopScroll = stop;
}

scrollBar.prototype.scroll = function(index)
{
 //get properties
 var barID = this.barsArray[index].barID;
 var width = this.barsArray[index].width;
 var height = this.barsArray[index].height;
 var interval = this.barsArray[index].interval;
 var direction = this.barsArray[index].direction;
 var stopScroll = this.barsArray[index].stopScroll;
 var preValue = this.barsArray[index].preValue;
 var maxValue = this.barsArray[index].maxValue;
 
 if ( stopScroll == true ) return;
 
 switch(direction)
 {
  case "up":
    preValue++;
    if ( preValue >= maxValue )
    {
     preValue = 0;
    }
    barID.scrollTop = preValue;
    break;
  case "down":
    preValue--;
    if ( preValue <= 0 )
    {
     preValue = maxValue;
    }
    barID.scrollTop = preValue;
    break;
  case "left":
    preValue++;
    if ( preValue >= maxValue )
    {
     preValue = 0;
    }
    barID.scrollLeft = preValue;
    break;
  case "right":
    preValue--;
    if ( preValue <=0 )
    {
     preValue = maxValue;
    }
    barID.scrollLeft = preValue;
    break;
 }
 this.barsArray[index].preValue = preValue;
}

//=================end of file===========================