Incorporate 4-module quiet zone by default

.noConflict() compliance: only reference $, not jQuery, inside the closure

README.md

@@ -9,7 +9,7 @@ It is based on a <a href='http://www.d-project.com/qrcode/index.html'>library</a
 which build qrcode in various language. <a href='http://jeromeetienne.github.com/jquery-qrcode'>jquery.qrcode.js</a> wraps
 it to make it easy to include in your own code.
 
-Show, dont tell, here is a <a href='examples/basic.html'>example</a>
+Show, dont tell, here is a <a href='https://github.com/jeromeetienne/jquery-qrcode/blob/master/examples/basic.html'>example</a>
 
 ## How to Use It
 

src/jquery.qrcode.js

@@ -11,6 +11,7 @@
 			render		: "canvas",
 			width		: 256,
 			height		: 256,
+			margin		: 4,
 			typeNumber	: -1,
 			correctLevel	: QRErrorCorrectLevel.H,
                         background      : "#ffffff",
@@ -30,15 +31,24 @@
 			var ctx		= canvas.getContext('2d');
 
 			// compute tileW/tileH based on options.width/options.height
-			var tileW	= options.width  / qrcode.getModuleCount();
+			var margin	= options.margin;
-			var tileH	= options.height / qrcode.getModuleCount();
+			var tileW	= options.width  / (qrcode.getModuleCount() + 2*options.margin);
+			var tileH	= options.height / (qrcode.getModuleCount() + 2*options.margin);
+
+			var isDark = function(x, y) {
+				x -= margin; y -= margin;
+				if(x < 0 || x >= qrcode.getModuleCount() || y < 0 || y >= qrcode.getModuleCount())
+				    return false;
+				else
+				    return qrcode.isDark(x, y);
+			}
 
 			// draw in the canvas
-			for( var row = 0; row < qrcode.getModuleCount(); row++ ){
+			for( var row = 0; row < qrcode.getModuleCount()+2*margin; row++ ){
-				for( var col = 0; col < qrcode.getModuleCount(); col++ ){
+				for( var col = 0; col < qrcode.getModuleCount()+2*margin; col++ ){
-					ctx.fillStyle = qrcode.isDark(row, col) ? options.foreground : options.background;
+					ctx.fillStyle = isDark(row, col) ? options.foreground : options.background;
 					var w = (Math.ceil((col+1)*tileW) - Math.floor(col*tileW));
-					var h = (Math.ceil((row+1)*tileW) - Math.floor(row*tileW));
+					var h = (Math.ceil((row+1)*tileH) - Math.floor(row*tileH));
 					ctx.fillRect(Math.round(col*tileW),Math.round(row*tileH), w, h);  
 				}	
 			}
@@ -62,17 +72,26 @@
 				.css('background-color', options.background);
 		  
 			// compute tileS percentage
-			var tileW	= options.width / qrcode.getModuleCount();
+			var margin	= options.margin;
-			var tileH	= options.height / qrcode.getModuleCount();
+			var tileW	= options.width / (qrcode.getModuleCount() + 2*margin);
+			var tileH	= options.height / (qrcode.getModuleCount() + 2*margin);
+
+			var isDark = function(x, y) {
+				x -= margin; y -= margin;
+				if(x < 0 || x >= qrcode.getModuleCount() || y < 0 || y >= qrcode.getModuleCount())
+				    return false;
+				else
+				    return qrcode.isDark(x, y);
+			}
 
 			// draw in the table
-			for(var row = 0; row < qrcode.getModuleCount(); row++ ){
+			for(var row = 0; row < (qrcode.getModuleCount() + 2*margin); row++ ){
 				var $row = $('<tr></tr>').css('height', tileH+"px").appendTo($table);
 				
-				for(var col = 0; col < qrcode.getModuleCount(); col++ ){
+				for(var col = 0; col < (qrcode.getModuleCount() + 2*margin); col++ ){
 					$('<td></td>')
 						.css('width', tileW+"px")
-						.css('background-color', qrcode.isDark(row, col) ? options.foreground : options.background)
+						.css('background-color', isDark(row, col) ? options.foreground : options.background)
 						.appendTo($row);
 				}	
 			}
@@ -83,7 +102,7 @@
 
 		return this.each(function(){
 			var element	= options.render == "canvas" ? createCanvas() : createTable();
-			jQuery(element).appendTo(this);
+			$(element).appendTo(this);
 		});
 	};
 })( jQuery );