[Qgis-developer] Problems choosing the color scheme with the "topocolour" plugin

[Barry Rowlingson]

On Thu, Sep 23, 2010 at 9:33 PM, Giovanni Manghi
<giovanni.manghi at gmail.com> wrote:
> Hi,
>
> I'm testing the "topocolour" plugin under qgis-trunk/Ubuntu and when it
> comes to choose the colour palette the dropdown doesn't show any.
>
> It is supposed to pick somewhere the palettes and copy them in the
> system, or it is just a bug?

 Ooh I wrote that...

 Once you've computed the graph colouring then the Layer Style tab
should be active, and that should have fields for Colour Scheme, Line
Type, Width, and Line Colour. The Colour Scheme drop-down should give
you a nice list of palettes derived from the ColorBrewer system.

 However the ColorBrewer palettes only supply palettes with a certain
number of colours, and if your map can only be coloured with 23 unique
colours then it may well be that the colour scheme drop-down is empty.
When you hit the 'Compute Colouring' button it should tell you how
many colours are needed.

 I suspect your map needs either only 1 or 2 colours or more than 8. I
need to handle these conditions better. Patches for topocolour
welcome. Source is in google code repo.

Barry