Re: [Usability] A (rather long) list of GNOME usability issues

[Matthew Thomas <mpt myrealbox com>]

On 17 Oct, 2005, at 11:50 AM, Owen Williams wrote:
> On Mon, 2005-10-17 at 13:30 +0300, Tuomas Kuosmanen wrote:
> > Another thing I have been pondering about lately is the "passthru"  
> > click to raise windows - some wm's used to have this as an option  
> > years ago - and I think Mac OS X does this too. What I mean is that  
> > if you click to raise a window, that click does not do anything in  
> > the program itself.

This is an application of Fitts Law. It's much quicker to bring a  
window to the front by clicking *anywhere* in it than by carefully  
finding a spot that doesn't have any controls in it.

In Mac OS, it's up to the app developer: a click can either raise the  
window (the normal behavior), raise the window and do something  
(exceptional, and therefore given the name "clickthrough"), or do  
something and *not* raise the window. In Mac OS Classic, pretty much  
the only example of clickthrough was the Launcher  
<http://www.bethel.edu/its/is/teaching-technology/serveraccess/images/ 
OS9/launcherwindow.gif> (even title bar close/grow/rollup buttons  
didn't allow clickthrough), but in OS X it's much more common.

Ideally, this allows optimization to particular use cases. For example,  
the iTunes mini player controls can be used without bringing the player  
window to the front, which saves time. And the usual case of just  
raising the window makes switching between windows much easier.

Similarly in Windows it's up to the app developer: for example,  
clicking in a background Microsoft Word or Excel window will raise the  
window but not change the selection. Hardly anybody notices this,  
though, because in Windows people usually have productivity app windows  
maximized.

> This is a horrible feature in my opinion.  I'm the IT department at an
> all-mac office, and I watch carefully when people use their computers.
> I've noticed that people will click on a button in a window, and then
> get momentarily confused when nothing happens.  This is because the
> window is being "raised" even if it is on a different monitor than the
> current raised window and has no other windows anywhere near it.  This
> behavior trains users to double-click everything, because sometimes  
> the first click doesn't "catch."
> ...

Clickthrough is a mess in Mac OS X (hence my use of "ideally" above),  
from a combination of poor implementation and arbitrary design  
decisions. Programs are supposed to make non-clickthrough controls in  
background windows look insensitive (which has the added benefits of  
making the active window more obvious and background windows less  
distracting); but sometimes they don't, especially if they don't use  
native controls (e.g. Firefox and Thunderbird). That's the cause of the  
problem described above. Similarly, some Cocoa controls -- such as  
toolbars and scrollbars -- have clickthrough by default while their  
Carbon counterparts don't; and in the case of scrollbars, unlike GTK  
vs. Qt, it's not visually obvious which toolkit a program uses.

GTK could implement clickthrough-off-by-default much more consistently  
than Carbon+Cocoa have, but to be understandable it would need to be  
implemented for XUL and Gecko too, because so many GTK-using OSes  
feature Firefox and/or Thunderbird prominently.

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