Say I want to hide a span when the user highlights a bit of text containing that span, with the intention of copying that text on to his clipboard.
For example:
<p>The dragon <span class="tooltip">a large, mythical beast</span> belched
fire at St. George.</p>
I have found that in Firefox Mac, span.tooltip will disappear from view (in accordance with my CSS declarations) but will show up in the clipboard when it's copied there. I figured (wrongly?) that if I said "onHighlight, hide tooltip," maybe this wouldn't happen.