Extending Bubble plots - Color scales (Was Re: #372971)

[Emmanuel Pacaud <emmanuel pacaud univ-poitiers fr>]

Le mardi 26 décembre 2006 à 18:45 +0100, Jean Bréfort a écrit :
> Hi,
>
> I have worked on that bug, (I attached a image to the bug report) but
> have some questions:
>
> - how should they be named? and in which family? (may be they should go
> with the bubble plots)

I think it's just an extended version of bubble plot with an additionnal
serie for colors, a marker shape setting and which request a pseudo 3d
axis. I don't see a good name for it. 

It would probably a good idea to push the marker setting to bubble
plots.

> - as the colors used for the markers are calculated, the color selectors
> are not needed in the style editor. We have several possibilities:
>       * don't display the selector (and possibly hide the associated labels)
>       * display them but set them insentitive
> I tried both, but I don't like the result. Any idea?

If we go the extended bubble plot route, let's see marker color setting
as a default color, overridden by the color serie. No need to hide or
disabled them.

> - We need some sort of legend for the color code. Should it be added to
> the already existing legend (we might have several series with different
> marker shapes) or do we need another legend? 

I don't think color scales should be displayed in the GogLegend object.
Their display should be handled by the pseudo3dAxis instance, probably
with a GogColorScale object, child of Pseudo3Daxis. Being a child of
GogAxis would allow to move them easily, like GogAxis labels.

We also need a gradient store, shared by all GogChart instances,
populated initially by a set of default gradients. These gradients needs
to be either continuous or discrete, and we should provide an editor for
custom ones. 

Here's some interesting examples found on the web.

http://emmanuel.pacaud.free.fr/screenshots/gnumeric/color-scale-01.gif
http://emmanuel.pacaud.free.fr/screenshots/gnumeric/color-scale-02.gif

Samuel, do you have a screenshot of a plot with a legend featuring what
you've asked for ?

        Emmanuel.