2D Canvas: low-level, 2D graphics rendering - HTML5 in Action - page 256

var Paddle = {
move : function () {
if ( Ctrl . left && ( this . x < Game . width - ( this . w / 2 ))) {
this . x += this . speed ;
} else if ( Ctrl . right && this . x > - this . w / 2 ) {
this . x += - this . speed ;
}
}
};
More key codes!
If you'd like to know more about the state of keyboard detection and get a complete list
of key codes, please see Jan Wolter's article “JavaScript Madness: Keyboard Events” ( ht-
tp://unixpapa.com/js/key.html ) .
Step 2: Add mouse control
Monitoring for mouse movement is similar to keyboard monitoring, except you need
to take into account the Canvas's position on the page and cross-reference it with the
mouse. To get the current mouse location, update Ctrl.init() and add a new
movePaddle() method with the following listing.