Re: [Usability] Faded File Extensions

[Matthew Paul Thomas <mpt myrealbox com>]

On 26 Dec, 2005, at 5:15 PM, Jason Hoover wrote:
> ...
> Somewhere between hiding the extensions and making them visible to
> rename them, is just hiding them until the user decides to rename the
> file, putting the cursor before the extension. (Which, I think may be
> what Apple does, but I didn't remember that until after I wrote it.)
> ...

AppleWorks and Microsoft Office for Mac both preselect "untitled" but 
not the file extension for overwriting in their default filenames 
("untitled.cwk", "untitled.doc", and so on). That's the most similar 
behavior I know of to what you describe. But clicking on a filename in 
the Finder selects the entire filename for overwriting, including the 
extension if it's visible.

The Finder has a "Show all file extensions" preference that is off by 
default, the converse of Windows Explorer's "Hide extensions for known 
file types" option that is on by default. Regardless of this setting, 
however, "deleting" the extension from the filename hides the extension 
but does not actually delete it. (I don't know where the "hide this 
file's extension" flag is stored.)

If you add an extension to a file that already has one, you get an 
alert of the form "Are you sure you want to change the extension from 
“.PDF” to “.gif”?" with the default button being "Keep .PDF". This 
happens even if the previous extension was hidden, which can be very 
confusing. And if you add an extension to a file that doesn't already 
have one, you get an alert of the form "Are you sure you want to add 
the extension “.gif” to the end of the name?" with the default button 
being "Don't Add". If you go ahead with either of these actions, of 
course, you make the file practically unopenable.

In short, it's hack upon confirmation alert upon hack, and a shining 
example of why you shouldn't use file extensions to indicate filetype.

--
Matthew Paul Thomas
http://mpt.net.nz/