[GRASS-dev] Region setting correction

[Maciej Sieczka]

Michael Barton napisa?(a):

> 1. If you run g.region from the command line‹either with arguments (e.g.,
> g.region ­p) or without arguments so that it starts one of the autogenerated
> GUI dialogs‹it sets and/or reports on the values in the WIND file. This is
> the way I described it a few minutes ago.

OK.

> 2. BUT, if you run g.region from the menu, there is anomalous behavior that
> may be the cause of considerable and repeated confusion. G.region started
> from the menus will REPORT (i.e., with ­p set) on the region of the
> currently active display window (i.e., whichever display currently has the
> focus). If you try to set something with g.region run from the menu, it
> seems to have NO EFFECT on a display

Ouch!

> OR on the WIND file.

OK.

> 3. However, if you set something from a g.region dialog run from the menu
> AND select Œzoom to current region¹ from the menu button on the toolbar, the
> display will match the g.region settings‹even though this is NOT in the WIND
> file. 

(dizzy)

> 4. If you set something from a g.region dialog started from the command line
> (or issue a g.region command with arguments) and select Œzoom to current
> region¹ from the menu button on the toolbar, it will have NO EFFECT on the
> display zooming. 

Yikes.

> 5. If you zoom interactively in a map display and select Œset current region
> (WIND file) to match display¹, this WILL change the  WIND file to match the
> display (check by running g.region ­p from the command line).

OK.

> At this point,  it can insert some rounding error in resetting the WIND file to match the
> display. I think this is what Maciek is seeing. I tried changing to a
> g.region ­a (align to current region) and it had no effect on this rounding
> error.

And when I inserted -a here and there to g.region calls in mapcanvas.tcl
it DID correct the rounding error. Only I'm not sure where exactly this
-a is really required! Please try once more.

> The map display interactive zooming and zoom menu button are behaving as
> they should. 
> 
> 1. Interactive zooming affects a dynamic region ONLY for that display and
> DOES NOT affect the WIND file

OK.

> 2. Selecting Œzoom to current region¹ DOES change the display to match the
> settings of g.region run from the menu‹but NOT from the command line.

(double dizzy)

> 3. Selecting Œset current region (WIND file)...¹ DOES change the WIND file
> to match the display.

OK.

> BUT (and a very confusing one at that), g.region run from the command line
> and g.region run from the menus do NOT always behave the same way with
> regard to the interactive zooming in a display. I have no idea why this is
> so.

Oh no.

> Maybe someone else can enlighten me.

These unresolved issues are extremely important. If they remain not
fixed for 6.2 it would be insane to force gis.m as a default GUI. People
will hate Grass and us.

Maciek