A loooong time ago, I wrote a bunch of event normalization code as a plugin to jQuery. In essence, the goal was the get events as close as possible to the DOM specification while retaining a sane file-size and backwards compatibility with existing code.
I wanted to add support for:
relatedTarget, which, on mouse movement, returns the element that the mouse was previously on when moving onto or off of an element
whichfor key events, which would return a normalized keyCode
metaKey, which would return the
Applekey on OSX, and the
ctrlkey in Windows (allowing stuff like
apple-Bto render something bold in OSX, but
ctrl-Bto do the same in Windows... the expected behavior)
- And a biggie:
whichsupport for buttons (1 for left-click, 2 for middle-click, and 3 for right-click).
I originally had some more grandiose plans, like supporting
offsetX across browsers and getting
keyCode to be the same cross-browser on keypresses, but those ended up either requiring unacceptable dependencies or requiring lots of messy code to get working.
Today, jQuery merged
which (for keys and buttons), and
metaKey into the core jQuery distribution, and we did it without adding a single byte to the current 20k cap on jQuery's filesize. We also added a whole slew of new features, without sacrificing our current cap. I say it's incredible, and thanks to the hard, tireless work of the jQuery Core Team. The speed improvements, which are the work of jQuery's maintainer, John Resig, also happened, sort of unexpectedly, without busting the 20k.
Back to the event normalization, I think you'll find that between the old normalization that was present since the early days (
event.pageX/pageY), and this new code, you'll be able to do all sorts of neat tricks without having to put much thought into browser compatibility issues.