On our whiteboard application, Chrome users are able to highlight the entire canvas if they drag their mouse a certain way:
Any ideas on how to prevent this from happening? You may give it a test yourself at:
http://whiteboard.rayku.com (then click the green 'start session' button).
Applying this CSS to the body seems to do the trick for me in Chrome:
-webkit-touch-callout: none; -webkit-user-select: none; -khtml-user-select: none; -moz-user-select: none; -ms-user-select: none; -o-user-select: none; user-select: none;
Others have said that these properties are not yet respected by Opera and IE, and instead, you need to set the unselectable attribute on the elements, like so:
I don't have either of those browsers, so I can't confirm this, but you can see these posts for more detail: