[GRASS-dev] Re: [GRASS5] Improvements to gis.m map canvas

[Glynn Clements]

Hamish wrote:

> > > Because it is likely that drawing a box by hand with a mouse will
> > > not exactly come up with the exact same x:y ratio of the current
> > > canvas.
> 
> Hi, slightly off-topic but,
> 
> Is it possible to use an XOR coloring to draw the zoom box as a inverse
> of the background instead of always yellow? The box disappears on yellow
> parts of the map..

No; the Tk canvas doesn't support XOR plotting.

One option is to use two identical boxes in different colours, with
the top box having a dash pattern while the bottom box is solid.

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