[GRASSGUI] graphic overlays

[Glynn Clements]

Michael Barton wrote:

> >> I want to suggest that most or all graphic overlays be done via wxPython
> >> rather than using GRASS d.* commands.
> >> 
> >> These are: north arrow, scale, grid (and geodetic lines maybe), and text.
> >> We¹ll need someone to design some nice (and GRASS distinctive) north arrows
> >> and scales.
> >> 
> >> I suggest that these be accessed through an item or items (popup checkbox
> >> menu?) on the map display tool bar, rather than having them added as layers.
> >> They should be able to be turned on and off of course, as well as being
> >> positioned with a mouse (the latter will be much easier if they are wxPython
> >> graphic objects). Each will need it¹s own dialog with options, but that
> >> shouldn¹t be too difficult to do.
> >> 
> >> Vector labels could go either way<as something done from the map display
> >> tool bar or as an independent layer.
> >> 
> >> Other opinions?
> > 
> > I suggest that this is implemented in such a way that the user can
> > easily choose to use the equivalent d.* commands instead, so that the
> > display contents can be exported as a script which can be used outside
> > of the GUI (i.e. with an X/PNG monitor).
> 
> This kind of negates the idea (I thought you were promoting too) of using
> native GUI functions for all 'decorations'.

FWIW, I don't support requiring the GUI in order to render anything
which might reasonably appear on a printed map (labels, scale bar,
legend etc).

These should all be achievable using d.* commands, and the GUI should
provide a convenient interface to those commands (e.g. using the mouse
to identify coordinates for placement).

> It's not hard to add a layer
> managers for d.grid, d.text, d.scalebar, etc. But it could clutter up the
> main control more. 
> 
> What if we could make it scriptable using wxPython graphic elements?

I'm not entirely sure what you mean by that.

But, essentially, I feel that it should be possible to save the
contents of the display as a script which will work on a system with
only core GRASS modules (no Python, no X server; can you render
wxPython graphics into an image file on a system with no X server?).

-- 
Glynn Clements <glynn at gclements.plus.com>