<?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin/" type="text/css"?> <window id="test-canvas" title="Canvas in XUL test" xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" xmlns:html="http://www.w3.org/1999/xhtml" onload="workWithCanvas();"> <script type="text/javascript"> function workWithCanvas() { var c = document.getElementById("canvas"); var ctx = c.getContext("2d"); ctx.fillStyle = "#ff0000"; ctx.fillRect(0, 0, 100, 100); } </script> <html:canvas id="canvas" width="100" height="100" style="width: 100px; height: 100px; max-height: 100px; max-width: 100px;"/> </window>