用htc实现CHECKBOX控件

/*
描述:        checkbox控件
版本:        1.1
备注:        checkbox控件背后跟随的文字
            是获取checkbox对象的htc_mylabel来显示的
            更新添加indeter属性,用来增加不确定的选择
*/
<public:component>
<public:attach event="oncontentready" onevent="fninit()" />
<public:attach event="onpropertychange" onevent="fnpropertychange()" />
<script language="javascript">
var checkboximg=window.document.createelement("img");
imagearray=[];
imagearray["checkbox_false"]="checkbox_false.gif";
imagearray["checkbox_false_down"]="checkbox_false_down.gif";
imagearray["checkbox_false_over"]="checkbox_false_over.gif";
imagearray["checkbox_true"]="checkbox_true.gif";
imagearray["checkbox_true_down"]="checkbox_true_down.gif";
imagearray["checkbox_true_over"]="checkbox_true_over.gif";
imagearray["checkbox_indeter"]="checkbox_indeter.gif";
imagearray["checkbox_indeter_down"]="checkbox_indeter_down.gif";
imagearray["checkbox_indeter_over"]="checkbox_indeter_over.gif";
function preload(path,obj){
    for(i in obj){
        this[i]=new image();
        this[i].src=path+obj[i];
        }
    return this;
    }
preb=new preload("images/",imagearray);
function fninit(){
    var o=element;
    if(o.type=="checkbox"){
        var _table=window.document.createelement("table");
        _table.cellspacing="0px";
        _table.cellpadding="0px";
        _table.border="0px";
        if(o.disabled){
            _table.style.filter="alpha(opacity=50)";
            }
        else{
            _table.style.filter="";
            }
        _table.style.display="inline";
        var _tr=_table.insertrow();
        var _td=_tr.insertcell();
        if (o.checked){
            checkboximg.src=preb["checkbox_true"].src;
            }
        else{
            checkboximg.src=preb["checkbox_false"].src;
            }
        if(o.indeter=="true"){
            o.indeterminate="true";
            checkboximg.src=preb["checkbox_indeter"].src;
            }
        _td.appendchild(checkboximg);
        _td=_tr.insertcell();
        _td.style.verticalalign="bottom";
        if(o.htc_mylabel){
            _td.innerhtml="&nbsp<label style='cursor: hand'>"+o.htc_mylabel+"</label>";
            }
        o.insertadjacentelement("afterend",_table);
        o.style.display="none";
        _table.attachevent("onmouseover",function(){baction("over")});
        _table.attachevent("onmouseout",function(){baction("out")});
        _table.attachevent("onmousedown",function(){baction("down")});
        _table.attachevent("onmouseup",function(){baction("up")});
        _table.attachevent("onclick",function(){fnclick()});
        }
    }
function fnpropertychange(){
    var o=element;
    switch(event.propertyname.tostring().tolowercase()){
        case "checked":
            baction("up");
            break;
        }
    }
function fnclick(){
    var o=element;
    if(o.type=="checkbox"){
        if(o.disabled)return;
        if(o.checked){
            checkboximg.src=preb["checkbox_false"].src;
            }
        else{
            checkboximg.src=preb["checkbox_true"].src;
            }

        o.checked=!o.checked;
        }
    }
function baction(action){
    var o=element;
    if(o.type=="checkbox"){
        if(o.disabled)return;
        if(action=="up"||action=="over"){
            if(o.indeterminate){
                checkboximg.src=preb["checkbox_indeter_over"].src;
                }
            else if(o.checked){
                checkboximg.src=preb["checkbox_true_over"].src;
                }
            else{
                checkboximg.src=preb["checkbox_false_over"].src;
                }
            }
        if(action=="out"){
            if(o.indeterminate){
                checkboximg.src=preb["checkbox_indeter"].src;
                }
            else if(o.checked){
                checkboximg.src=preb["checkbox_true"].src;
                }
            else{
                checkboximg.src=preb["checkbox_false"].src;
                }

            }
        if(action=="down"){
            if(o.indeterminate){
                checkboximg.src=preb["checkbox_indeter_down"].src;
                }
            else if(o.checked){
                checkboximg.src=preb["checkbox_true_down"].src;
                }
            else{
                checkboximg.src=preb["checkbox_false_down"].src;
                }
            o.indeterminate=false;
            }
        }
    }
</script>
</public:component>

测试例子:

<html>
<head>
<title> 新文档 </title>
<meta name="generator" content="editplus">
<meta name="author" content="flashsoft">
<meta name="keywords" content="">
<meta name="description" content="flashsoft">
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<style type="text/css">

input.checkbox{
    behavior:url("behaviors/checkbox.htc");cursor: hand;
    }

</style>
</head>
<body>
<input name="chk1" type="checkbox" class="checkbox" htc_mylabel="音乐" checked>
<input name="chk1" type="checkbox" class="checkbox" htc_mylabel="体育" disabled>
<input name="chk1" type="checkbox" class="checkbox" htc_mylabel="新闻">
<input name="chk1" type="checkbox" class="checkbox" htc_mylabel="不确定属性1" indeter="true" checked>
<input name="chk1" type="checkbox" class="checkbox" htc_mylabel="不确定属性2" indeter="true" disabled>
<input name="chk1" type="checkbox" class="checkbox" htc_mylabel="不确定属性3" indeter="true">
</body>
</html>