[GRASS-user] GRASS "custom" applications

[Michael Barton]

Hi Tom,

See below

On 7/27/07 5:01 AM, "Thomas Adams" <Thomas.Adams at noaa.gov> wrote:

> Michael,
> 
> Thanks for your feedback. I understand how the GRASS GUI is set-up — as
> you explain it. I suppose my problem is one of not wanting to break the
> current GUI, to avoid problems when new upgrades are released, yet
> simplify the user's interaction with the GRASS GUI for the purpose of
> using the tools I have in mind. Some of this, I understand, comes down
> to a design decision on my part.

Yes. What we have now is a general GUI that attempts to make all GRASS
functions available to the user. However, it is simpler than most people
imagine to craft a custom one for a specific target audience.

> I do have a broader question at fits in
> with what I am asking about, but also affects others who may have
> similar needs, namely:
> 
> Should there be some facility within the GRASS GUI that allows people
> such as myself to generate some GUI tool that can simply be "dropped"
> into GRASS and appear in some consistent way in the main GRASS GUI? The
> main GRASS menu bar *may*, for instance, have a new 'Other' or 'Add-on'
> or 'Custom' or 'Tools' or whatever menu item to go with the existing
> ones ('Raster', 'Vector', 'Imagery', 'Volumes', etc.). Or rather than a
> main menu bar item, there could be an icon selection button, for
> instance. So that, if someone like myself were to add some new GUI
> component in the way I previously describe, then the item would appear
> under the new menu item. The 'dropping' into GRASS may consist of some
> standard subdirectory in the GRASS build where a subdirectory would be
> created by me or others (for each of their 'projects'), where the coding
> and some naming convention, etc. would be expected to meet certain
> guidelines in order for it to appear in the GRASS GUI.
> 
> In this way, there would be both straight-forward programming standards
> and easy user access to the new tool without breaking the interface when
> new GRASS GUI builds came along. Just a thought…

This is actually 2 questions. For the main one, there are a couple attempts
in progress to do exactly what you describe. These are Benjamin Ducke's GEM
(GRASS Extension Manager) and William Kyngesbury's GRASS modbuild. There
have been some discussions about merging these 2 efforts. From an observer's
perspective watching discussions on the dev list, there seem to be 2 issues
that need to be resolved: 1) where to put any custom modules given that the
'best' place varies by OS; and 2) how to automatically embed custom module
commands into the GUI menu. There is progress being made on both fronts. If
you have interest in this, help is needed to move this forward.

The second, implied question, may be more helpful to your immediate needs.
Both for TclTk and wxPython, the actual interface files are simply ASCII
text scripts. So you can modify them to your heart's content without
compiling. This means that you can (as I've done) engage in a lot of trial
and error experimentation quickly: change a script, quit and restart the
interface (i.e., with gis.m for TclTk or wxgrass for wxPython), watch it
crash, do it again. ;-)

If you have a custom interface for GRASS, you can simply drop it into the
current GUI folder, make a new folder and change the target of the calling
script (gis.m or wxgrass), or make a new calling script (e.g., mygui) that
starts your custom app.

I hope this encourages you to try out some of these suggestions.

Michael

> 
> 
> Michael Barton wrote:
>> It is relatively straightforward to create a custom application with GRASS
>> because all (or very nearly all) GRASS functions can be run as a series of
>> ASCII commands with arguments and switches.
>> 
>> In essence, this is what the current TclTk GUI and development wxPython GUI
>> do--execute a series of GRASS commands.
>> 
>> One easy thing that you could do to start is simply begin with the current
>> TclTk scripts and get rid of anything you don't want to show from the menus
>> (gmmenu.tcl) or toolbars (gism.tcl and mapdisp.tcl).
>> 
>> Michael
>> 
>> 
>> On 7/25/07 3:48 PM, "Thomas Adams" <Thomas.Adams at noaa.gov> wrote:
>> 
>>   
>>> Folks:
>>> 
>>> Please take a look at this: http://www.erh.noaa.gov/er/ohrfc/fop.html
>>> 
>>> which was created using ArcGIS 9.x through some customization of the GUI
>>> to make the creation of the graphic a one-step process. Now, this
>>> graphic could easily be created using a script in GRASS (or, presumably,
>>> in ArcGIS), so it's an uninteresting example. But we use the graphic to
>>> depict areas of potential flooding (as indicated by the legend) by
>>> drawing color-filled polygons with text annotations to indicate the
>>> period over which the flooding is likely, as shown here:
>>> 
>>> http://www.srh.noaa.gov/wgrfc/fop/wgrfcfop.html
>>> 
>>> for a different region of the U.S. My question is this: how should I
>>> proceed to do this through some customization of the GRASS interface to
>>> "hide" GRASS details using a somewhat simplified GUI tool. I should add,
>>> that the flood risk polygons are exported to a text format file, which
>>> is then transmitted to a national center to generate a National product
>>> like this:
>>> 
>>> http://www.srh.noaa.gov/wgrfc/fop/wgrfcfop.html
>>> 
>>> I am also interested in an unrelated 'custom applcation' that would
>>> essentially combine a series of GRASS analyses into single step
>>> processes utilizing the GRASS GUI to initiate the analyses and set some
>>> parameters ‹ for various hydrologic analyses, including:
>>> 
>>> (1) identification of snow elevation zones (disconnected regions within
>>> a watershed, above a certain elevation)
>>> (2) basin boundary delineation for a set of watershed outlets (utilizing
>>> r.water.outlet, etc.)
>>> (3) model parameter estimation
>>> 
>>> I think most of this could be done as GRASS add-ons; would this be the
>>> way to go, or would embellishing the GRASS Tcl/Tk interface be necessary
>>> (something I would rather NOT do for several reasons).
>>> 
>>> Thanks for any and all feedback!
>>> 
>>> Tom
>>>     
>> 
>> __________________________________________
>> Michael Barton, Professor of Anthropology
>> Director of Graduate Studies
>> School of Human Evolution & Social Change
>> Center for Social Dynamics and Complexity
>> Arizona State University
>> 
>> phone: 480-965-6213
>> fax: 480-965-7671
>> www: http://www.public.asu.edu/~cmbarton
>> 
>>   
> 

__________________________________________
Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton