如何将jquery-jscrollpane中的滚动条移动到textarea光标位置

Question

我尝试在jsfiddle中实施。当textarea展开滚动条时，不要移动到textarea光标。

JavaScript的：

function addJScrollPaneTo($container) {
    // use jScrollPane jquery plugin
    $container.jScrollPane({
        verticalGutter: 1,
        stickToBottom: true,
        enableKeyboardNavigation : false,
        autoReinitialise: true
    });
}

function appendTextareaTo($container) {

    var $textarea = $("<textarea />");

    // set textarea attribute
    $textarea.css({'border': 'medium none'});
    $textarea.width($container.width());

    // use TextAreaExpander jquery plugin
    $textarea.TextAreaExpander($container.height()-1);

    $container.append($textarea);
}

// for padding with elem
function appendContainer(elem) {

    var $container = $("<div />");

    // set container attribute
    $container.width($(elem).width());
    $container.height($(elem).height());

    $(elem).append($container);
    appendTextareaTo($container);
    addJScrollPaneTo($container);
}

function setCSS(elem) {
    $(elem).css({
        'border': 'thin solid #CCCCCC',
        'padding': '1px'
    });
}

setCSS("#test");
appendContainer("#test");

HTML：

<div id="test" style="width: 235px; height: 50px;"></div>

CSS：

.jspContainer
{
    overflow: hidden;
    position: relative;
}

.jspPane
{
    position: absolute;
}

.jspVerticalBar
{
    position: absolute;
    top: 0;
    right: 0;
    width: 16px;
    height: 100%;
    background: red;
}

.jspHorizontalBar
{
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 16px;
    background: red;
}

.jspVerticalBar *,
.jspHorizontalBar *
{
    margin: 0;
    padding: 0;
}

.jspCap
{
    display: none;
}

.jspHorizontalBar .jspCap
{
    float: left;
}

.jspTrack
{
    background: #dde;
    position: relative;
}

.jspDrag
{
    background: #bbd;
    position: relative;
    top: 0;
    left: 0;
    cursor: pointer;
}

.jspHorizontalBar .jspTrack,
.jspHorizontalBar .jspDrag
{
    float: left;
    height: 100%;
}

.jspArrow
{
    background: #50506d;
    text-indent: -20000px;
    display: block;
    cursor: pointer;
}

.jspArrow.jspDisabled
{
    cursor: default;
    background: #80808d;
}

.jspVerticalBar .jspArrow
{
    height: 16px;
}

.jspHorizontalBar .jspArrow
{
    width: 16px;
    float: left;
    height: 100%;
}

.jspVerticalBar .jspArrow:focus
{
    outline: none;
}

.jspCorner
{
    background: #eeeef4;
    float: left;
    height: 100%;
}

/* Yuk! CSS Hack for IE6 3 pixel bug :( */
* html .jspCorner
{
    margin: 0 -3px 0 0;
}
.jspVerticalBar {
    background: none;
    border-radius: 5px 5px 5px 5px;
    right: 0px;
    width: 5px;
}
 .jspScrollable .jspHorizontalBar {
    background: none;
    bottom: 0px;
    height: 10px;
    border-radius: 5px 5px 5px 5px;
}

.jspScrollable .jspTrack {
    background: none repeat scroll 0 0 #D1D3D5;
    border-radius: 5px 5px 5px 5px;
}
.jspScrollable .jspDrag {
    background: none repeat scroll 0 0 #5E6063;
    border-radius: 5px 5px 5px 5px;
}