[whatwg] Hide placeholder on input controls on focus

[Benjamin Stürmer]

>> Just as an added data-point (that I only noticed today) - Windows 7's
>> placeholder implementation in the Start menu and Explorer's search box:
>>   - Focusing the input box with tab/Control-E or autofocus when opening
>> the Start menu does *not* hide the placeholder.
>>   - Control-A or clicking in the textbox hides the placeholder.
>
> I was not aware of the possibility to distinguish between clicking in a
> textbox and other ways to focus it. This behaviour seems to be very
> user-friendly to me.

I think this is a neat feature in the Windows Start Menu, but I think
it's a bad idea to distinguish between the two sources of focus in the
case of a placeholder text. If I have an on-load handler that focuses
a different element depending on some logic (for example, autoselect
the first empty field in a form), that behavior would then result in a
different appearance than if I set the autofocus attribute, even
though the page's behavior would be identical from the user's
perspective.

Other than that, though, the formatting used in the Windows Start Bar
and several other places already mentioned by others -- light grey and
italicized -- seems like the best option to me. I'd also be in favor
of giving placeholder text opacity on focus, though italicizing the
text seems like a sufficiently strong signal that that might not be
necessary.

I have anecdotal evidence of user confusion both from placeholders
vanishing on focus and from placeholder text looking the same as input
text. The first was when some of my users got confused by an app I
built before I realized that IE was hiding placeholders on focus. The
second was me, testing the same app -- I know how placeholders work,
but I kept instinctively trying to highlight the text because it
exactly matched the formatting of actual values.

~ Benjamin