/**
* Cornerz 0.6 - Bullet Proof Corners
* Jonah Fox (jonah@parkerfox.co.uk) 2008
* 
* Usage: $('.myclass').curve(options)
* options is a hash with the following parameters. Bracketed is the default
*   radius (10)
*   borderWidth (read from BorderTopWidth or 0)
*   background ("white"). Note that this is not calculated from the HTML as it is expensive
*   borderColor (read from BorderTopColor)
*   corners ("tl br tr bl"). Specify which borders
*   fixIE ("padding") - attmepts to fix IE by incrementing the property by 1 if the outer width/height is odd.

CHANGELIST from  v0.4

0.5 - Now attempts to fix the odd dimension problem in IE 
0.6 - Added semicolons for packing and fixed a problem with odd border width's in IE

*/

; (function($) {

	if ($.browser.msie && document.namespaces["v"] == null) {
		document.namespaces.add("v", "urn:schemas-microsoft-com:vml");
		var ss = document.createStyleSheet().owningElement;
		ss.styleSheet.cssText = "v\\:*{behavior:url(#default#VML);}"
	}

	$.fn.cornerz = function(options) {

		function canvasCorner(t, l, r, bw, bc, bg) {
			var sa, ea, cw, sx, sy, x, y, p = 1.57, css = "position:absolute;";
			if (t)
			{ sa = -p; sy = r; y = 0; css += "top:-" + bw + "px;"; }
			else
			{ sa = p; sy = 0; y = r; css += "bottom:-" + bw + "px;"; }
			if (l)
			{ ea = p * 2; sx = r; x = 0; css += "left:-" + bw + "px;" }
			else
			{ ea = 0; sx = 0; x = r; css += "right:-" + bw + "px;"; }

			var canvas = $("<canvas width=" + r + "px height=" + r + "px style='" + css + "' ></canvas>");
			var ctx = canvas[0].getContext('2d');
			ctx.beginPath();
			ctx.lineWidth = bw * 2;
			ctx.arc(sx, sy, r, sa, ea, !(t ^ l));
			ctx.strokeStyle = bc;
			ctx.stroke();
			ctx.lineWidth = 0;
			ctx.lineTo(x, y);
			ctx.fillStyle = bg;
			ctx.fill();
			return canvas;
		};

		function canvasCorners(corners, r, bw, bc, bg) {
			var hh = $("<div style='display: inherit' />"); // trying out style='float:left' 
			$.each(corners.split(" "), function() {
				hh.append(canvasCorner(this[0] == "t", this[1] == "l", r, bw, bc, bg));
			});
			return hh;
		};

		function vmlCurve(r, b, c, m, ml, mt, right_fix) {
			var l = m - ml - right_fix;
			var t = m - mt;
			return "<v:arc filled='False' strokeweight='" + b + "px' strokecolor='" + c + "' startangle='0' endangle='361' style=' top:" + t + "px;left: " + l + ";width:" + r + "px; height:" + r + "px' />";
		}


		function vmlCorners(corners, r, bw, bc, bg, w) {
			var h = "<div style='text-align:left; '>";
			$.each($.trim(corners).split(" "), function() {
				var css, ml = 1, mt = 1, right_fix = 0;
				if (this.charAt(0) == "t") {
					css = "top:-" + bw + "px;";
				}
				else {
					css = "bottom:-" + bw + "px;";
					mt = r + 1;
				}
				if (this.charAt(1) == "l")
					css += "left:-" + bw + "px;";
				else {
					css += "right:-" + (bw) + "px; "; // odd width gives wrong margin?
					ml = r;
					right_fix = 1;
				}

				h += "<div style='" + css + "; position: absolute; overflow:hidden; width:" + r + "px; height: " + r + "px;'>";
				h += "<v:group  style='width:1000px;height:1000px;position:absolute;' coordsize='1000,1000' >";
				h += vmlCurve(r * 3, r + bw, bg, -r / 2, ml, mt, right_fix);
				if (bw > 0)
					h += vmlCurve(r * 2 - bw, bw, bc, Math.floor(bw / 2 + 0.5), ml, mt, right_fix);
				h += "</v:group>";
				h += "</div>";
			});
			h += "</div>";

			return h;
		};

		var settings = {
			corners: "tl tr bl br",
			radius: 10,
			background: "white",
			borderWidth: 0,
			fixIE: true
		};
		$.extend(settings, options || {});

		var incrementProperty = function(elem, prop, x) {
			var y = parseInt(elem.css(prop)) || 0;
			elem.css(prop, x + y);
		}


		return this.each(function() {

			var $$ = $(this);
			var r = settings.radius * 1.0;
			var bw = (settings.borderWidth || parseInt($$.css("borderTopWidth")) || 0) * 1.0;
			var bg = settings.background;
			var bc = settings.borderColor;
			bc = bc || (bw > 0 ? $$.css("borderTopColor") : bg);

			var cs = settings.corners;

			if ($.browser.msie) {//need to use innerHTML rather than jQuery
				h = vmlCorners(cs, r, bw, bc, bg, $(this).width());
				this.innerHTML += h;

			}
			else  //canvasCorners returns a DOM element
				$$.append(canvasCorners(cs, r, bw, bc, bg));


			if (this.style.position != "absolute")
				this.style.position = "relative";

			this.style.zoom = 1; // give it a layout in IE

			if ($.browser.msie && settings.fixIE) {
				var ow = $$.outerWidth();
				var oh = $$.outerHeight();

				if (ow % 2 == 1) {
					incrementProperty($$, "padding-right", 1);
					incrementProperty($$, "margin-right", 1);
				}

				if (oh % 2 == 1) {
					incrementProperty($$, "padding-bottom", 1);
					incrementProperty($$, "margin-bottom", 1);
				}
			}

		}

    );

	}
})(jQuery);