Re: XYcolor plots

[John Denker <jsd av8n com>]

Since this is considered a "work in progress" perhaps it
is timely to ask a question about the design philosophy:

Why do colormaps need UUIDs?

Spreadsheets don't have UUIDs. Spreadsheets are vastly more
important than colormaps. Assigning UUIDs seems to increase
the complexity for users and for the implementation team.

The alternative seems much simpler:
 a) Store the active colormap in the spreadsheet file. This
  colormap does not need a name or a UUID.

 b) If the user wants to save the colormap separately, let
  them save it in a file, with a filename of their choosing
  in a directory of their choosing ... not some non-mnemonic
  filename in a filing cabinet stuck in a disused lavatory
  with a sign on the door saying 'Beware of the Leopard'.

 c) If the user wants to load a colormap, let them choose
  one using the open-a-file dialog in the usual way.

 d) The internal content of the colormap file doesn't need
  to include a name or a UUID. The external filename is a
  much nicer identifier.

 e) Getting rid of UUIDs removes the obstacle to /editing/
  the colormaps. This makes life simpler for everybody.

Additional design considerations:

 *) Rather than a "color=" attribute it would be better to
  have separate "stroke=" and "fill=" attributes. Maybe
  also "shape=" and "size=".

 *) At some point it becomes easier to handle the general
  case, which requires at least a six dimensional plot:
        x, y, stroke, fill, shape, size

  Bubble plots are a special case of this.
  Color XY plots are a different special case.
  Plain XY plots are an even simpler special case.

 *) Maybe also do something clever with line thickness,
  line color, and line dash style.