javascript DOM编程艺术书中的一些工具函数-白红宇

javascript DOM编程艺术书中的一些工具函数

阅读量：5152 次

发布时间：2019-06-13

本文共 3524 字，大约阅读时间需要 11 分钟。

function moveElement(elementID,final_x,final_y,interval){

if(!document.getElementById) return false;

if(!document.getElementById(elementID)) return false;

var elem = document.getElementById(elementID);

if(elem.movement){

clearTimeout(elem.movement);

}

var xpos = parseInt(elem.offsetLeft);

var ypos = parseInt(elem.offsetTop);

if(xpos == final_x && ypos == final_y){

return true;

}

if(xpos<final_x){

var dist = Math.ceil((final_x - xpos)/10);

xpos = xpos + dist;

}

if(xpos>final_x){

var dist = Math.ceil((xpos - final_x)/10);

}

if(ypos<final_y){

var dist = Math.ceil((final_y - ypos)/10);

ypos = ypos + dist;

}

if(ypos>final_y){

var dist = Math.ceil((ypos - final_y)/10);

ypos = ypos - dist;

}

elem.style.left = xpos + "px";

elem.style.top = ypos + "px";

var repeat = "moveElement('"+elementID+"',"+final_x+","+final_y+","+interval+")";

elem.movement = setTimeout(repeat,interval);

}

function prepareSlideshow(){  if(!document.getElementsByTagName) return false;    if(!document.getElementById) return false;    if(!document.getElementById("intro")) return false;    var intro = document.getElementById("intro");    var slideshow = document.createrElement("div");    slideshow.setAttribute("id","slideshow");    var frame = document.createElement("img");    frame.setAttribute("src","images/frame.gif");    frame.setAttribute("alt","");    frame.setAttribute("id","frame");    slideshow.appendChild(frame);    var preview = document.createElement("img");    preview.setAttribute("src","images/slideshow.gif");    preview.setAttribute("alt","a glimpse of what awaits you");    preview.setAttribute("id","preview");    slideshow.appendChild(preview);    insertAfter(slideshow,intro);    var links = document.getElementsByTagName("a");    var destination;    for(var i=0; i

//表格隔行变色function stripetables(){  if(!document.getElementsByTagName) return false;    var tables = document.getElementsByTagName("table");    for(var i=0; i

//为不支持placeholder的浏览器添加这个功能function resetfields(whichform){  if(Modernizr.input.placeholder) return ;    for(var i=0; i

//ajaxfunction getHTTPObject(){  if(typeof XMLHttpRequest == "undefined"){      XMLHttpRequest = function(){          try{
   return new ActiveXObject("Msxml2.XMLHTTP.6.0");}              catch(e){}            try{
   return new ActiveXObject("Msxml2.XMLHTTP.3.0");}              catch(e){}            try{
   return new ActiveXObject("Msxml2.XMLHTTP");}              catch(e){}            return false;        }    }    return new XMLHttpRequest();}function displayAjaxLoading(element){  while(element.hasChildNodes()){      element.removeChild(element.lastChild);    }    var content = document.createElement("img");    content.setAttribute("src","images/loading.gif");    content.setAttribute("alt","Loading...");    element.appendChild(content);}function submitFormWidthAjax(whichform,thetarget){  var request = getHTTPObject();    if(!request){
   return false;}    displayAjaxLoading(thetarget);    var dataParts = [];    var element;    for(var i=0; i
     
      ([\s\S]+)<\/article>/);                if(matches.length>0){                  thetarget.innerHTML = matches[1];                }else{                  thetarget.innerHTML = '
      Oops,there was an error. Sorry.
';                }            }else{              thetarget.innerHTML = '
      ' + request.statusText + '
';            }        }    };    request.send(data);    return true;}function prepareForms(){  for(var i=0; i