Code:
// Contributors
// Ilkka Huotari at http://www.editsite.net
// Mathieu 'p01' HENRI at http://www.p01.org/
// http://seky.nahory.net/2005/04/rounded-corners/
// Steven Wittens at http://www.acko.net/anti-aliased-nifty-corners
// Original Nifty Corners by Alessandro Fulciniti at http://pro.html.it/esempio/nifty/
function NiftyCheck() {
if(!document.getElementById || !document.createElement) {
return false;
}
var b = navigator.userAgent.toLowerCase();
if (b.indexOf("msie 5") > 0 && b.indexOf("opera") == -1) {
return false;
}
return true;
}
function Rounded(className, sizex, sizey, sizex_b, sizey_b) {
var bk;
if (!NiftyCheck()) return;
if (typeof(sizex_b) == 'undefined')
sizex_b = sizex;
if (typeof(sizey_b) == 'undefined')
sizey_b = sizey;
var v = getElements(className);
var l = v.length;
for (var i = 0; i < l; i++) {
color = get_current_style(v[i],"background-color","transparent");
bk = get_current_style(v[i].parentNode,"background-color","transparent");
AddRounded(v[i], bk, color, sizex, sizey, true);
AddRounded(v[i], bk, color, sizex_b, sizey_b, false);
}
}
Math.sqr = function (x) {
return x*x;
};
function Blend(a, b, alpha) {
var ca = Array(
parseInt('0x' + a.substring(1, 3)),
parseInt('0x' + a.substring(3, 5)),
parseInt('0x' + a.substring(5, 7))
);
var cb = Array(
parseInt('0x' + b.substring(1, 3)),
parseInt('0x' + b.substring(3, 5)),
parseInt('0x' + b.substring(5, 7))
);
return '#' + ('0'+Math.round(ca[0] + (cb[0] - ca[0])*alpha).toString(16)).slice(-2).toString(16)
+ ('0'+Math.round(ca[1] + (cb[1] - ca[1])*alpha).toString(16)).slice(-2).toString(16)
+ ('0'+Math.round(ca[2] + (cb[2] - ca[2])*alpha).toString(16)).slice(-2).toString(16);
return '#' + ('0'+Math.round(ca[0] + (cb[0] - ca[0])*alpha).toString(16)).slice(-2).toString(16)
+ ('0'+Math.round(ca[1] + (cb[1] - ca[1])*alpha).toString(16)).slice(-2).toString(16)
+ ('0'+Math.round(ca[2] + (cb[2] - ca[2])*alpha).toString(16)).slice(-2).toString(16);
}
function AddRounded(el, bk, color, sizex, sizey, top) {
if (!sizex && !sizey)
return;
var i, j;
var d = document.createElement("div");
d.style.backgroundColor = bk;
var lastarc = 0;
for (i = 1; i <= sizey; i++) {
var coverage, arc2, arc3;
// Find intersection of arc with bottom of pixel row
arc = Math.sqrt(1.0 - Math.sqr(1.0 - i / sizey)) * sizex;
// Calculate how many pixels are bg, fg and blended.
var n_bg = sizex - Math.ceil(arc);
var n_fg = Math.floor(lastarc);
var n_aa = sizex - n_bg - n_fg;
// Create pixel row wrapper
var x = document.createElement("div");
var y = d;
x.style.margin = "0px " + n_bg + "px";
x.style.height='1px';
x.style.overflow='hidden';
// Make a wrapper per anti-aliased pixel (at least one)
for (j = 1; j <= n_aa; j++) {
// Calculate coverage per pixel
// (approximates circle by a line within the pixel)
if (j == 1) {
if (j == n_aa) {
// Single pixel
coverage = ((arc + lastarc) * .5) - n_fg;
}
else {
// First in a run
arc2 = Math.sqrt(1.0 - Math.sqr((sizex - n_bg - j + 1) / sizex)) * sizey;
coverage = (arc2 - (sizey - i)) * (arc - n_fg - n_aa + 1) * .5;
// Coverage is incorrect. Why?
coverage = 0;
}
}
else if (j == n_aa) {
// Last in a run
arc2 = Math.sqrt(1.0 - Math.sqr((sizex - n_bg - j + 1) / sizex)) * sizey;
coverage = 1.0 - (1.0 - (arc2 - (sizey - i))) * (1.0 - (lastarc - n_fg)) * .5;
}
else {
// Middle of a run
arc3 = Math.sqrt(1.0 - Math.sqr((sizex - n_bg - j) / sizex)) * sizey;
arc2 = Math.sqrt(1.0 - Math.sqr((sizex - n_bg - j + 1) / sizex)) * sizey;
coverage = ((arc2 + arc3) * .5) - (sizey - i);
}
x.style.backgroundColor = Blend(bk, color, coverage);
if (top)
y.appendChild(x);
else
y.insertBefore(x, y.firstChild);
y = x;
var x = document.createElement("div");
x.style.height='1px';
x.style.overflow='hidden';
x.style.margin = "0px 1px";
}
x.style.backgroundColor = color;
if (top)
y.appendChild(x);
else
y.insertBefore(x, y.firstChild);
lastarc = arc;
}
if (top)
el.insertBefore(d, el.firstChild);
else
el.appendChild(d);
}
function getElements(className) {
var elements = [];
var el = document.getElementsByTagName('DIV');
var regexp=new RegExp("\\b"+className+"\\b");
for (var i = 0; i < el.length; i++)
{
if (regexp.test(el[i].className))
elements.push(el[i]);
}
return elements;
}
function get_current_style(element,property,not_accepted)
{
var ee,i,val,apr;
try
{
var cs=document.defaultView.getComputedStyle(element,'');
val=cs.getPropertyValue(property);
}
catch(ee)
{
if(element.currentStyle)
{
apr=property.split("-");
for(i=1;i<apr.length;i++) apr[i]=apr[i].toUpperCase();
apr=apr.join("");
val=element.currentStyle.getAttribute(apr);
}
}
if((val.indexOf("rgba") > -1 || val==not_accepted) && element.parentNode)
{
if(element.parentNode != document)
val=get_current_style(element.parentNode,property,not_accepted);
else
val = '#FFFFFF';
}
if (val.indexOf("rgb") > -1 && val.indexOf("rgba") == -1)
val = rgb2hex(val);
if (val.length == 4)
val = '#'+val.substring(1,1)+val.substring(1,1)+val.substring(2,1)+val.substring(2,1)+val.substring(3,1)+val.substring(3,1);
return val;
}
function rgb2hex(value)
{
var x = 255;
var hex = '';
var i;
var regexp=/([0-9]+)[, ]+([0-9]+)[, ]+([0-9]+)/;
var array=regexp.exec(value);
for(i=1;i<4;i++) hex += ('0'+parseInt(array[i]).toString(16)).slice(-2);
return '#'+hex;
}
