/* Copyright (c) 2007 David Wees ( davidwees@gmail.com - http://unitorganizer.com/myblog )
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 *
 * $LastChangedDate$
 * $Rev$
 *
 * Version: 1.0
 *
 * Requires: jQuery 1.1.3+
 */

/**
 * Creates a (linear)     gradient fill in the element(s) matched.
 *
 * (String) rightcolor - The color in hexadecimal format (ie '#354546') of the rightside of the element - '#000000' by default
 * (String) leftcolor - The color in hexadecimal format (ie '#354546') of the rightside of the element - '#ffffff' by default 
 * (String) topcolor - The color in hexadecimal format (ie '#354546') of the rightside of the element - '#000000' by default 
 * (String) bottomcolor - The color in hexadecimal format (ie '#354546') of the rightside of the element - '#ffffff' by default
 * (Boolean) horizontal - Should the gradient be horizontal or vertical?  horizontal by default
 * (Number) opacity - The opacity of the gradient, given as an integer from 1 to 100
 * 
 * @example $("#testdiv").gradient({ leftcolor: '#ffffff', rightcolor: '#336699' });
 * @result Creates a gradient from left to right of #ffffff to #336699 with 100% opacity
 *
 * @example $("#testdiv").gradient({ topcolor: '#ffffff', bottomcolor: '#336699', horizontal: false, opacity: 80 });
 * @result Creates a gradient from top to bottom of #ffffff to #336699 and opacity of 80
 *
 * @name gradient
 * @param Map options Optional settings to configure the way the gradient occurs, horizontal or vertical and its colors.
 * should return the jQuery object match of elements
 * @type Object
 * @cat Plugins/Gradient
 */
jQuery.fn.gradient = function(settings) {
	this.each(function () {  // keep track of which element is being transformed
			  var el = jQuery(this);
			  var slice;
			  // Find out if the Dimensions plugin has been installed
			  
			  // use the Dimensions plugin information if it exists
			  var height = settings.height;
			  var width = settings.width;
			  var position = el.offset();
			  var top = position.top;
			  var left = position.left;
			  var selector = settings.selector;
			  
			  //opacity
			  var opacity = 'opacity:' 
			  + settings.opacity/100 + ';' 
			  + 'filter:alpha(opacity=' + settings.opacity + ');'
			  + '-moz-opacity: ' + Math.round(settings.opacity/10)/10 + ';';
			  
			  
			 // alert(selector + " " + height + " " + width);
			  // what's the point? the gradient won't be seen anyway, also it avoids division by 0
			  if (width == 0 || height == 0) return;
			  
			  // define default settings
			  settings = jQuery.extend({ 
									   rightcolor: '#000000', 
									   leftcolor: '#ffffff', 
									   topcolor: '#000000', 
									   bottomcolor: '#ffffff', 
									   horizontal: true, 
									   opacity: false
									   }, settings || {});
			  
			  //horizontal

			  if (settings.horizontal) {
			  var r = [ parseInt(settings.rightcolor.substr(1,2), 16), parseInt(settings.rightcolor.substr(3,2), 16), parseInt(settings.rightcolor.substr(5,2), 16) ];
			  var l = [ parseInt(settings.leftcolor.substr(1,2), 16), parseInt(settings.leftcolor.substr(3,2), 16), parseInt(settings.leftcolor.substr(5,2), 16) ];
			  var d = [ (r[0] - l[0])/width, (r[1] - l[1])/width, (r[2] - l[2])/width ];
			  var w = width;
			 
			  for (var i = 0; i < w; i++) {
			  var c = [ Math.floor(l[0] + i*d[0]), Math.floor(l[1] + i*d[1]), Math.floor(l[2] + i*d[2]) ];
			  var theSlice = '<div style="font-size:1px;height:'+height+'px;position:absolute;' 
			  + 'left: ' + i + 'px;' 
			  + 'top: ' + 0 + 'px;'
			  + 'width: ' + (settings.horizontal ? '1' : width) + 'px;'
			  + opacity 
			  + 'background-color: rgb(' + c[0] + ',' + c[1] + ',' + c[2] + ');" ></div>';
			  
			  jQuery(selector).prepend(theSlice);   
			  }
			  
			  } 
			  //vertical
			  else {
			  var r = [ parseInt(settings.bottomcolor.substr(1,2), 16), parseInt(settings.bottomcolor.substr(3,2), 16), parseInt(settings.bottomcolor.substr(5,2), 16) ];
			  var l = [ parseInt(settings.topcolor.substr(1,2), 16), parseInt(settings.topcolor.substr(3,2), 16), parseInt(settings.topcolor.substr(5,2), 16) ];
			  var d = [ (r[0] - l[0])/height, (r[1] - l[1])/height, (r[2] - l[2])/height ];
			  
			  for (var i = 0; i < height; i++) {
			  var c = [ Math.floor(l[0] + i*d[0]), Math.floor(l[1] + i*d[1]), Math.floor(l[2] + i*d[2]) ];
			  var theSlice = '<div style="font-size:1px;height:1px;position:absolute;' 
			  + 'top: ' + i + 'px;'
			  + 'left: ' + 0 + 'px;' 
			  + 'width: ' + width + 'px;'
			  + opacity 
			  + 'background-color: rgb(' + c[0] + ',' + c[1] + ',' + c[2] + ');" ></div>';
			  jQuery(selector).prepend(theSlice);   
			  }
			  }
			  });
	return this;
};