Features vs. Preferences

As most people know, there has been some flamewars accusing Gnome developers of removing options for the benefit of “idiot users”. I’ve definitely been responsible for removing preferences from some parts of the desktop in the past. Probably the most dramatic is the drive mount applet, which started off with a preferences dialog with the following options:

  • Mount point: which mount point should the icon watch the state of?
  • Update interval: at what frequency should the mount point be polled to check its status?
  • Icon: what icon should be used to represent this mount point. A selection of various drive type icons were provided for things like CDs, Floppys, Zip disks, etc.
  • Mounted Icon and Unmounted Icon: if “custom” was selected for the above, let the user pick custom image files to display the two states.
  • Eject disk when unmounted: whether to attempt to eject the disk when the unmount command is issued.
  • Use automount-friendly status test: whether to use a status check that wouldn’t cause an automounter to mount the volume in question.

These options (and the applet in general) survived pretty much intact from the Gnome 1.x days. However the rest of Gnome (and the way people use computers in general) had moved forward since then, so it seemed sensible to rethink the preferences provided by the applet:

  1. Nautilus’s volume handling has matured a lot since then, and been pushed down to the platform as the GnomeVFSVolumeMonitor API. This API makes it possible to enumerate mounted volumes and mount points on the system, so we can do a lot better than providing an entry box and file chooser to select a mount point.
  2. The GnomeVFSVolumeMonitor provides asynchronous notification of mount/unmount events, removing the need for the applet to poll the status. If the applet isn’t polling, then there is no reason for it to provide the update interval preference.
  3. The GnomeVFSVolumeMonitor API provides icon names for volumes depending on the drive type. If we can detect that a disk is a floppy or a cdrom or whatever, why ask them what sort of icon to use? This change also means that the icon can be picked from the user’s selected icon theme, providing better integration with the rest of the desktop (not to mention the accessibility benefits when the HighContrast icon theme is used).
  4. Certain types of volumes always make sense to eject on unmount. Other volumes don’t. Since we know the volume type, we should be able to just do the right thing.
  5. Since the applet is no longer directly checking the mount point status, the “Use automout-friendly status test” preference doesn’t make sense. But even if it was applicable, it is the sort of preference that only has one sane value: assuming both types of status check work, why wouldn’t you want to use the one that works with automounters?

The other major change I made was due to a change in the types of volumes people mount: USB devices. If you have a fixed number of mount points/devices you care about, then the old model works pretty well. If you have a large number of devices, and rarely plug them all in at once, you probably don’t want to create drive mount applets for all of them. My solution was to alter the drive mount applet to display a button for each user mountable volume on the system rather than one applet per mount point.

The result was an applet with no preferences. However, I’d contend that it has more features than before. It has been improved further since then, to provide media-type specific options (e.g. start the movie player if you insert a DVD Video disc).

9 thoughts on “Features vs. Preferences”

  1. The problem I have with the current drive mount applet (and the reason it no longer graces my panel) is that it’s all or nothing – you can’t have a subset of mountable volumes and you can’t alter the layout. I have a 4-in-1 flash card reader, 2 cdroms and an ide floppy drive. So, I get dumped with 7 items inefficiently layed out (I use a single 48 pix panel; old school). I only use 1 of the 4 flash slots, so I’d rather ignore the other 3, and vertical items make a lot more sense for my panel dimensions.

  2. James, you have provided us with a most wonderful example of our wonderfulness.

    Philip/Luca, this is a common feature request, and is probably relevant to people with lots of little devices, so is a patch forthwith? If you were going to implement this, I would recommend storing a mask of drives to hide, rather than a list of drives to show. That way new devices that have never been seen before always appear, and could then be hidden by the user.

  3. Exactly, there is a huge difference between features and options. In the ideal case, the only choice a user _ever_ has to make should be “what do I want to do”. And that is what GNOME is all about.

    Some people insist on having unlimited customizability available and I understand that GNOME isn’t the right desktop for them. But that is not the same as functionality. Functionality means to me “the ability to do something”, not “a specific method to do something”.

  4. I agree with the problem of having too many devices. The first thing to do would be insure that their order is somewhat predictable.

    I think that the problem woud better be managed at a higher level. What I have in mind would be something like having a user preference file for libhal where keys could be specified for known devices.

    For example, a removable device could have the key “.user_pref.show” with the values “always”, “when-mountable”
    , “when-mounted” or “never”

  5. > I only use 1 of the 4 flash slots, so I’d rather ignore the other 3

    Wouldn’t it make sense to just automatically ignore drives that couldn’t be mounted, such as card slots with no cards in them? You don’t want to see them because there’s nothing you could do with them.

  6. it would be enough if people can select which drives he wants to display on the panel. Some people only want their cd/dvd drives, but the rest they don’t care about. I really hope such a highly requested feature will be implemented!

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