RE: Do Re Mi (was: Q on Text Properties popup menu-shouldn'titusethepointerposition, not the cursor position?)

["Drew Adams" <drew.adams@oracle.com>]

    	Also, in some cases it might be
    	good to map two dimensions of the color space at a time,
      not just one.

        It could be done, I suppose. But, unless you would limit
        that to 45 degree
        diagonals (equal changes in two dimensions), which is not
        that useful,

    I think we are miscommunicating.  I'm thinking that horizontal arrows
    could alter one dimension in color space, while vertical arrows
    could alter another dimension.

    Since it doesn't have to be limited to arrows, another pair of keys
    could move in the third dimension of color space.

You can only press one arrow at a time (you can press two, but only one
takes effect).

Using modifier keys it would be possible to truly alter two dimensions at
once, but only in equal (or predefined, constant) proportions. You could
assign any key sequence to such a predefined change, of course.

To allow altering more than one dimension at the same time, in varying
proportions, you need more graphic input - a la the Word dialog box.

Currently, in the doremi color commands, you use up and down arrows for each
color component (no matter which component), and just type [rgbhsv] at any
time to change to a different component. E.g. r up up g down down b down up
up v down down. Simple.

To respond to your suggestion, it would be possible to change things so that
you could use up/down for, say, red, left/right for, say, green, and two
other keys for blue. The (small) advantage is not having to type a `r', `g',
or `b' to switch between components.

That is what I do, for instance, for the doremi frame movement and resizing
commands. In that case, there is a natural association between left/right
arrows and horizontal movement or resizing, and similarly for up/down &
vertical.

For color components, I don't see the advantage of not having to specify the
current component [rgbhsv] outweighing the confusion of keeping straight
which component corresponds to which keys. And, since there are two color
models (RGB & HSV), you would need six key-pair assignments, or you would
still need some way to switch between the models (RGB vs HSV).

        To change more than one color component at the same
        time, it's better to have an interface that shows a color
        space, such as in the Word dialog box.

    That sounds plausible.  I wonder if that could be programmed in Emacs
    Lisp.  Also, some toolkits may have a widget for doing this job,
    and maybe Emacs could invoke it somehow.

Those are things to explore. Bob Chassell suggested using existing Gimp code
that does this kind of thing. Otherwise, it could be done in Lisp, I'm sure,
using small colored characters as the tiny color swatches (no need for
graphics) - a block character could be used.