source: BMXNET_RPMS_dotNET_UTILITIES-BMX/branch/BMX41000/IHS BMX Framework/IndianHealthService.BMXNet.GeneratedDocumentation/Help/Scripts/Dropdown.js

// Dropdown menu control

function Dropdown(activatorId, dropdownId) {

        // store activator and dropdown elements
        this.activator = document.getElementById(activatorId);
        this.dropdown = document.getElementById(dropdownId);
        this.activatorImage = document.getElementById(activatorId + "Image");

        // wire up show/hide events
        registerEventHandler(this.activator,'mouseover', getInstanceDelegate(this, "show"));
        registerEventHandler(this.activator,'mouseout', getInstanceDelegate(this, "requestHide"));
        registerEventHandler(this.dropdown,'mouseover', getInstanceDelegate(this, "show"));
        registerEventHandler(this.dropdown,'mouseout', getInstanceDelegate(this, "requestHide"));

        // fix visibility and position
        this.dropdown.style.visibility = 'hidden';
        this.dropdown.style.position = 'absolute';
        this.reposition(null);

        // wire up repositioning event
        registerEventHandler(window, 'resize', getInstanceDelegate(this, "reposition"));


}

Dropdown.prototype.show = function(e) {
        clearTimeout(this.timer);
        this.dropdown.style.visibility = 'visible';
        if (this.activatorImage != null)
            this.activatorImage.src = dropDownHoverImage.src;
        if (this.activator != null)
            this.activator.className = "filterOnHover";
}

Dropdown.prototype.hide = function(e) {
        this.dropdown.style.visibility = 'hidden';
        if (this.activatorImage != null)
            this.activatorImage.src = dropDownImage.src;
        if (this.activator != null)
            this.activator.className = "filter";
}

Dropdown.prototype.requestHide = function(e) {
        this.timer = setTimeout( getInstanceDelegate(this, "hide"), 250);
}

Dropdown.prototype.reposition = function(e) {

        // get position of activator
        var offsetLeft = 0;
        var offsetTop = 0;
        var offsetElement = this.activator;
        
        while (offsetElement) {
                offsetLeft += offsetElement.offsetLeft;
                offsetTop += offsetElement.offsetTop;
                offsetElement = offsetElement.offsetParent;
        }

        // set position of dropdown relative to it
        this.dropdown.style.left = offsetLeft;
        this.dropdown.style.top = offsetTop + this.activator.offsetHeight;
}

Dropdown.prototype.SetActivatorLabel = function(labelId)
{
    // get the children of the activator node, which includes the label nodes
    var labelNodes = this.activator.childNodes;


    for(var labelCount=0; labelCount < labelNodes.length; labelCount++)
    {
            if(labelNodes[labelCount].tagName == 'LABEL')
            {
                var labelNodeId = labelNodes[labelCount].getAttribute('id');
                    if (labelNodeId == labelId)
                    {
                    labelNodes[labelCount].style.display = "inline";
                    }
                    else
                    {
                    labelNodes[labelCount].style.display = "none";
                    }
            }
    }
}