Seeing the forest (was Re: Fileselection Widget)

[Kenneth Albanowski <kjahds kjahds com>]

On Thu, 24 Dec 1998, Joel Becker wrote:

> On Thu, Dec 24, 1998 at 09:14:31AM +0100, Michael Baumer wrote:
> > Has anybody been working on the fileselection widget lately? 
> > I would like to improve the usability of this dialog.
> > 
> > I think especially of the following:
> > - replace the Directory List and the "History" Bar by a TreeList
> 
> Michael,
> 	If you do this, I would ask that you call it a FileselectTree
> widget.  I do not like the Treelist style of M$ file selection, and
> I actually like the current format of the file selection dialog.  I
> would prefer maybe to have a choice of whiche fileselct to use or some
> other such comprimise.

Is anyone familiar with GUI widgets (in some other GUI package) that
provide the same general concepts as the Tree (directory selection), but
aren't trees, or at least don't have some of the same flaws? The more
trees I see, the more I'm beginning to loathe them, unfortunately I've not
seen any good replacements. When they have a small set of contents, with a
limited amount of nesting, they work fine, but when they get large and are
used for the retrieval of large amounts of data, they get obnoxious.

Some problems with the Common Tree:

	If the parents of the current nodes are off the top of the widget,
you can't tell where you are, or how deep you are.

	Losing your place is very simple. There aren't any bookmarks, or
even a "find" command built in to the widget. 

	Get too deep, and you need to scroll horizontally, for no
justifiable reason. (It's not justifiable because there is completely
empty white space to the left of the item, and both you and the widget
know this. The width of the white space is the only useful information,
and that isn't worth having to scroll.)

	Comparing areas is very difficult. You may need to open/close
branches, and possibly scroll horizontally. 

	Viewing the linear sequence (in-order depth-then-breadth or vice
versa) isn't easy. 

	Opening or closing a branch can alter the appearence of the widget
significantly, perhaps changing the scroll position as well. This abrupt a
jump seems to be very good at making the user lose his position.

Some places I've seen trees: Lots of places under Windows, including file
selection boxes, and help menus, of various types. Even the primary
documentation of many Microsoft development thingies is now based on a
tree widget. 

Some fixes I've seen: 

	Apple makes the "disclosure triangles" (the things you click to
open or close a branch) on their trees animate briefly, calling your
visual attention to the position where a branch is going to change. 

	Microsoft animates the contents of the tree itself in the same
situation, "sliding" the contents vertically to open or close room for a
branch to appear. This again focuses visual attention, though is far less
subtle then the Apple approach (and thus is far more likely to be
annoying). 

	The NeXtStEp style directory brower, which isn't a tree at all. 
Easier to see than describe, and it only solves a few of the issues I
mention, while creating new ones.

	Non-rectangular data visualization techniques allow the display of
a "tree" (acyclic connected graph with a specified root, nominally with
order and distance) with different space requirements, and different
availabilty of the displayed information. Some, like the ones based on a
Euclidian transform of a hyperbolic geometry, permit the display of an
infinite amount of data in a finite area (some of the data is infinitely
small, of course). These techniques aren't suitable for all types of data,
may not be familiar to users, and seem to be subject to much patent
congestion.

	Hyperbolic displays:
	<http://www.acm.org/sigchi/chi95/proceedings/papers/jl_bdy.htm>
	<http://www.inxight.com/Content/7.html>

	And I believe this one, though it is down at the moment:
	<http://www.physics.orst.edu/~bulatov/HyperProf/applet.html>

	Pseduo-orthogonal displays:
	<http://www.elastictech.com/>

	All sorts of stuff:
	<http://www.parc.xerox.com/istl/projects/uir/projects/InformationVisualization.html>

Is anyone aware of any other variations on this theme, or any discussions
in HMI circles? Remember that a wide variety of UI objects may reduce to
the same tree display problem (directory displays, project browsers,
code-folding editors, network browsers, etc.)

Happy Holidays,
Ken
-- 
Kenneth Albanowski (kjahds@kjahds.com, CIS: 70705,126)