﻿jQuery.fn.corner = function(o) {
    function hex2(s) {
        var s = parseInt(s).toString(16);
        return (s.length < 2) ? '0' + s : s;
    };
    function gpc(node) {
        for (; node && node.nodeName.toLowerCase() != 'html'; node = node.parentNode) {
            var v = jQuery.css(node, 'backgroundColor');
            if (v.indexOf('rgb') >= 0) {
                rgb = v.match(/\d+/g);
                return '#' + hex2(rgb[0]) + hex2(rgb[1]) + hex2(rgb[2]);
            }
            if (v && v != 'transparent')
                return v;
        }
        return '#ffffff';
    };
    function getW(i) {
        switch (fx) {
            case 'round': return Math.round(width * (1 - Math.cos(Math.asin(i / width))));
            case 'cool': return Math.round(width * (1 + Math.cos(Math.asin(i / width))));
            case 'sharp': return Math.round(width * (1 - Math.cos(Math.acos(i / width))));
            case 'bite': return Math.round(width * (Math.cos(Math.asin((width - i - 1) / width))));
            case 'slide': return Math.round(width * (Math.atan2(i, width / i)));
            case 'jut': return Math.round(width * (Math.atan2(width, (width - i - 1))));
            case 'curl': return Math.round(width * (Math.atan(i)));
            case 'tear': return Math.round(width * (Math.cos(i)));
            case 'wicked': return Math.round(width * (Math.tan(i)));
            case 'long': return Math.round(width * (Math.sqrt(i)));
            case 'sculpt': return Math.round(width * (Math.log((width - i - 1), width)));
            case 'dog': return (i & 1) ? (i + 1) : width;
            case 'dog2': return (i & 2) ? (i + 1) : width;
            case 'dog3': return (i & 3) ? (i + 1) : width;
            case 'fray': return (i % 2) * width;
            case 'notch': return width;
            case 'bevel': return i + 1;
        }
    };
    o = (o || "").toLowerCase();
    var keep = /keep/.test(o);                       // keep borders?
    var cc = ((o.match(/cc:(#[0-9a-f]+)/) || [])[1]);  // corner color
    var sc = ((o.match(/sc:(#[0-9a-f]+)/) || [])[1]);  // strip color
    var width = parseInt((o.match(/(\d+)px/) || [])[1]) || 10; // corner width
    var re = /round|bevel|notch|bite|cool|sharp|slide|jut|curl|tear|fray|wicked|sculpt|long|dog3|dog2|dog/;
    var fx = ((o.match(re) || ['round'])[0]);
    var edges = { T: 0, B: 1 };
    var opts = {
        TL: /top|tl/.test(o), TR: /top|tr/.test(o),
        BL: /bottom|bl/.test(o), BR: /bottom|br/.test(o)
    };
    if (!opts.TL && !opts.TR && !opts.BL && !opts.BR)
        opts = { TL: 1, TR: 1, BL: 1, BR: 1 };
    var strip = document.createElement('div');
    strip.style.overflow = 'hidden';
    strip.style.height = '1px';
    strip.style.backgroundColor = sc || 'transparent';
    strip.style.borderStyle = 'solid';
    return this.each(function(index) {
        var pad = {
            T: parseInt(jQuery.css(this, 'paddingTop')) || 0, R: parseInt(jQuery.css(this, 'paddingRight')) || 0,
            B: parseInt(jQuery.css(this, 'paddingBottom')) || 0, L: parseInt(jQuery.css(this, 'paddingLeft')) || 0
        };

        if (jQuery.browser.msie) this.style.zoom = 1; // force 'hasLayout' in IE
        if (!keep) this.style.border = 'none';
        strip.style.borderColor = cc || gpc(this.parentNode);
        var cssHeight = jQuery.curCSS(this, 'height');

        for (var j in edges) {
            var bot = edges[j];
            strip.style.borderStyle = 'none ' + (opts[j + 'R'] ? 'solid' : 'none') + ' none ' + (opts[j + 'L'] ? 'solid' : 'none');
            var d = document.createElement('div');
            var ds = d.style;

            bot ? this.appendChild(d) : this.insertBefore(d, this.firstChild);

            if (bot && cssHeight != 'auto') {
                if (jQuery.css(this, 'position') == 'static')
                    this.style.position = 'relative';
                ds.position = 'absolute';
                ds.bottom = ds.left = ds.padding = ds.margin = '0';
                if (jQuery.browser.msie)
                    ds.setExpression('width', 'this.parentNode.offsetWidth');
                else
                    ds.width = '100%';
            }
            else {
                ds.margin = !bot ? '-' + pad.T + 'px -' + pad.R + 'px ' + (pad.T - width) + 'px -' + pad.L + 'px' :
                                    (pad.B - width) + 'px -' + pad.R + 'px -' + pad.B + 'px -' + pad.L + 'px';
            }

            for (var i = 0; i < width; i++) {
                var w = Math.max(0, getW(i));
                var e = strip.cloneNode(false);
                e.style.borderWidth = '0 ' + (opts[j + 'R'] ? w : 0) + 'px 0 ' + (opts[j + 'L'] ? w : 0) + 'px';
                bot ? d.appendChild(e) : d.insertBefore(e, d.firstChild);
            }
        }
    });
};
