/*
 * LinScroll-http://uicss.cn/
 * Version 2.1.2008080701
 
 * Copyright (c) 2008 cuikai(uicss.cn)
 *
 * To Run This Code jQuery 1.1.3.1(http://www.jQuery.com) Required.
 *
 *
 */

jQuery.fn.setScroll = function(_scroll, _scroll_up, _scroll_down, _scroll_bar) {
    this.each(function() {
        var _bar_margin = 3;
        //create scroll dom
        //        var _scroll_control = jQuery('<div class="scroll_zone">').width(_scroll.width).css({ 'position': 'absolute', 'float': 'none', margin: 0, padding: 0 }).css('background', 'url(' + _scroll.img + ')');
        //        var _scroll_control_up = jQuery('<img class="scroll_down">').attr('src', _scroll_up.img).width(_scroll.width).css({ 'z-index': '1000', 'position': 'absolute', 'top': '0', 'float': 'none', margin: 0, padding: 0 });
        //        var _scroll_control_down = jQuery('<img class="scroll_down">').attr('src', _scroll_down.img).width(_scroll.width).css({ 'z-index': '1000', 'position': 'absolute', 'bottom': '0', 'float': 'none', margin: 0, padding: 0 });
        //        var _scroll_control_bar = jQuery('<img class="scroll_bar">').attr('src', _scroll_bar.img).width(_scroll.width).css({ 'z-index': '1500', 'position': 'absolute', 'float': 'none', margin: 0, padding: 0, height: _scroll_bar.height + 'px' }).css('top', _scroll_up.height + _bar_margin + 'px');
        var _scroll_control = jQuery('<div class="scroll_zone">').width(_scroll.width).css({ 'z-index': '1000', 'position': 'absolute', 'float': 'none', margin: 0, padding: 0 }).css('background', 'url(' + _scroll.img + ') repeat-y top center');
        var _scroll_control_up = jQuery('<div class="scroll_down">').width(_scroll.width).css({ 'z-index': '-1', 'position': 'absolute', 'top': '0', 'float': 'none', margin: 0, padding: 0, height: '2px' });
        var _scroll_control_down = jQuery('<div class="scroll_down">').width(_scroll.width).css({ 'z-index': '-1', 'position': 'absolute', 'bottom': '0', 'float': 'none', margin: 0, padding: 0, height: '2px' });
        var _scroll_control_bar = jQuery('<div class="scroll_bar">').width(_scroll.width).css({ 'z-index': '1500', 'position': 'absolute', 'float': 'none', margin:0, padding: 0, height: '22px' }).css('background', 'url(' + _scroll_bar.img + ')');

        _scroll_control.append(_scroll_control_up);
        _scroll_control.append(_scroll_control_bar);
        _scroll_control.append(_scroll_control_down);

        var _oheight = jQuery(this).css('height').substring(0, jQuery(this).css('height').indexOf('px'));
        var _owidth = jQuery(this).width();
        var _ocontent = jQuery(this).html();

        if (jQuery(this).attr('scrollHeight') <= _oheight) return;

        var _content_zone = jQuery('<div>').html(_ocontent).css({ width: _owidth - 10 + 'px', height: _oheight + 'px', overflow: 'hidden', 'float': 'none', margin: 0, padding: 0 });

        jQuery(this).css({ 'overflow': 'hidden' });
        jQuery(this).empty().append(_content_zone).css({ position: 'relative' }).append(_scroll_control.css({ left: _owidth - _scroll.width + 'px', top: '0', height: _oheight + 'px', margin: 0, padding: 0 }));

        //register drag event
        jQuery(this).find('.scroll_bar')
        .mousedown(
            function() {
                jQuery(document).mousemove(
                    function(e) {
                        var _content = _content_zone.get(0);
                        var lastProgress = _scroll_control_bar.attr('progress');
                        _scroll_control_bar.attr('progress', e.pageY);
                        var nowProgress = _scroll_control_bar.css('top');
                        nowProgress = nowProgress.substring(0, nowProgress.indexOf('px'));
                        nowProgress = Number(nowProgress) + Number(e.pageY - lastProgress);
                        var preProgress = nowProgress / (_oheight - _scroll_up.height - _scroll_down.height - _scroll_bar.height - (2 * _bar_margin));
                        _content.scrollTop = ((_content.scrollHeight - _content.offsetHeight) * preProgress);
                        if (nowProgress < (_scroll_up.height + _bar_margin) || nowProgress > (_oheight - (_scroll_down.height + _scroll_bar.height + _bar_margin))) return false;
                        try { _scroll_control_bar.css('top', nowProgress + 'px'); } catch (e) { }
                        return false;
                    }
                );
                return false;
            }
        )
        .mouseout(
            function() {
                jQuery(document).mouseup(
                    function() {
                        jQuery(document).unbind('mousemove');
                    }
                )
            }
        )

    });
}