Make canvas occupy as much space as possible

Question

I'm trying to make my HTML5 Canvas occupy as much space as possible. I'm making a game fore Firefox OS that uses the canvas and testing with the Firefox OS simulator.

By "as much space as possible", I mean the whole screen, without scrollbars.

Ideally, a cross-platform way (that also works on Android and iOS) is preferred.

Answer 1

You need to do a few things, set the the canvas position to absolute, and make sure there is no padding, or margins set in the containing element.

The following is what I use in all of my canvas demos

CSS

body, html {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}
canvas {
    position:absolute;
}

JavaScript

var canvas = document.getElementById("canvas"),
    width = window.innerWidth,
    height = document.body.offsetHeight;

window.onresize = function () {
    height = canvas.height = document.body.offsetHeight;
    width = canvas.width = document.body.offsetWidth;
};

Full Screen Demo