Thanks for your report.

In the move tool, shift is currently used to move the active layer, and without
shift, the layer underneath the mouse pointer is selected.

We also use the contrl and alt keys to move paths and selections respectively.

It is pretty easy to constrain yourself to horizontal or vertical motion using
the cursor keys (shift + cursor to go faster).

Can you suggest an alternative reworking of this interface which would be better?

Dave.

Well, using the cursor keys for placing an object is useful when you want to be
precise, but when it comes to moving a layer a long way in the image, it's
really less easy.

I would add that it feels quite "unnatural" to use shift, control and alt for
selecting different types of elements (layers, paths, selections) -- why not
simply put tool options accessible by a shortcuts ?

I also think that it's much more common to want to make a constrained movement
rather than selecting a particular set of objects (paths, for instance).

So what I suggest :
1) Shift is used to constrain the movement (many apps use this convention)
2) Alt is used to switch between active layer / object under the cursor mode
3) People who want to only move a particular type could enable/disable these in
the options

Finally, I would add that I personnaly find that selecting the active layer is
what I use most, compared to the layer under the cursor. Mainly because in
images with many layers you usuall pick the wrong one.

I agree with the reporter here, even if this would imply a redesign of the
usage of keyboard modifiers.  There are several conflicts already (see bug
#120973 and maybe also bug #51198).  Such a redisign has been discussed
several times but no good proposal has been made yet.  A proposal must take
all tools into account in order to improve the consistency of the user
interface (and if possible be similar to other applications).

So although I think that using Shift for constraining the movement is a good
idea (especially if other apps are using it) this can only be changed if the
current usage of Shift vs. Ctrl in other tools is also changed (e.g., all
painting tools, zoom tool, etc.).

Maybe we should mark this as a duplicate of bug #120973 and hope that someone
will post a detailled proposal there?

Is there any document on the usage of modifiers for each tool ? I would be happy
to study it and help you redesign a "more consistent" set of rules for a proposal.

I don't think that we have any up-to-date one-page "cheat sheet" listing all
modifiers for all tools.  However, you can look at the help pages (or at
http://docs.gimp.org/) and have a look at chapter 3 "Toolbox".  In this chapter,
the individual pages for the tools list the modifiers that can be used.  As far
as I know, these pages are rather accurate except for some minor details that
can be considered as bugs (pressing Shift+Ctrl is not the same as Ctrl+Shift
while working with the paint tools).  The most accurate source of information
for all tools is of course the source code.

I think that it is better to mark this bug as a duplicate of bug #120973.  If
you come up with a good proposal for the usage of modifiers, please add it to
that bug report or post it to the gimp-developer mailing list.  It may be a
good idea to explain the reason for any major change: for example, consistency
with other applications (which ones?), frequency of use of some combinations,
interaction with some window managers and how they already use some modifiers,
etc.

*** This bug has been marked as a duplicate of 120973 ***

GIMP comes with a "cheat sheet" in form of docs/quick_reference.ps. This
document is probably somewhat outdated. The LaTeX sources of it are however
contained in CVS and in the tarball, so someone could update this reference.
Perhaps it could be added to the GIMP user manual then. That would be a nice
start for a tool shortcut / modifier redesign also.