gmc: open folder in new view

[Ben Liblit <liblit cs berkeley edu>]

Over at Gnotices, a brief discussion recently took place regarding gmc
and opening folders in new windows.  I would like to follow up on that
with this broader audience.


I began the discussion by asking:

> Is it possible, yet, to open up a folder view in a new window? Up
> until now, it has only been possible to double-click a folder and
> get a view that replaces the current one.  It is fiendishly difficult
> to open up a view of a folder in a *new* window instead.  Perhaps
> some modifier key, or double-clicking with a different button?


Federico Mena-Quintero quickly replied:

> Select File->Create New Window.  Then open your directory.


However, I was not quite satisfied, and wrote something along the
following general lines:

OK, that does work.  But I would argue that it is inconvenient,
because it redirects the user's attention away from the folder in
question.

Perhaps this is subjective, but in my mind I think of opening a folder
in a new window as an operation performed on a folder.  Thus, it
should be possible to do it by manipulating the folder icon directly
in some way.  The current scheme models opening a folder in a new view
as an operation performed on the GMC application: you open a new view.
Then, changing that new view to a different folder is done by
manipulating the folder directly.

Is my view valid? Can opening a folder in a new view be thought of as
an operation performed on a folder? If so, then there should be some
way to do it using direct manipulation.  Consider, for example:

  - Single middle-mouse click in KDE's KFM opens a new view of a
    folder.

  - Single middle-mouse click in Netscape Navigator follows a link in
    a new browser window.

  - Netscape Navigator also offers "Open Link in New View" as a
    context menu item for any link.

  - Double left-mouse click in Windows Explorer opens a new view of a
    folder.

  - Double left-mouse click in MacOS Finder opens a new view of a
    folder.

So there is certainly precedent for this idea, that opening something
in a new view should be a direct action on that thing, rather than an
indirect two-step action as in gmc today.  In the Unix environment,
there is also precedent for associating this functionality with the
middle mouse button.

Can I propose that double middle-mouse click be assigned this role in
GMC? I believe that this would not conflict with any existing binding.
We can already distinguish single click, double click, and drag using
the left button, so presumably we can do the same for the middle
button.  (Please correct me if I am wrong.)  Furthermore, the existing
"File->Create New Window" technique would remain available for people
without three-button mice.  It might also be appropriate to add an
"Open in New Window" menu item to the right-mouse context pop-up menu
for folders.