Technology for Geoinformatics

Native GUI is one of the key points for the future development of GRASS GIS. It is crucial for GRASS user and especially connected to newcomers. GRASS offers high capability to analyze and manipulate spatial data, and covers many application areas of GIS projects. However, it shows an incomplete and scarcely intuitive graphical user interface, which causes slow performance of many options such as layout of maps. A large number of GIS professionals use MS-Windows and Macintosh operating systems. Until recently, GRASS run on these platforms not without problems. Additionally, the user interface of GRASS has lagged behind modern GUI design, making it much harder to operate.

The current standard GRASS GUI is written in Tcl programming language using Tk graphical toolkit. In the last years the limitations of Tcl/Tk toolkit appeared to be prohibitive for the future development. The new generation of GRASS GUI is written in the Python programming language using wxPython - a blending of the wxWidgets library for Python.

wxGUI will appear as the default GRASS GUI in main stable release of 2008 - GRASS 6.4.0.

We hope that improvements in the GUI will help to bring more GIS users and professionals into the GRASS community, in turn leading to further advances in GRASS and GIS in general and ultimately a benefit for the public.

wxGUI - a new generation of GUI for GRASS GIS

• Portability, enabling GRASS to be fully functional on the GNU/Linux, Unix, MacOSX and MS-Windows operating systems;
• Ease of Use, providing all the features commonly found in state of the art GIS applications;
• Extensibility, all tools integrated into GUI including digitization, georectification, image classification, etc.

Fig. 1: wxGUI welcome screen (GNU/Linux and MS Windows)

Description

• Layer Manager
• Map Display Window

• Vector digitizer
• Attribute Table Manager
• Nviz extension
• Profile analysis tool
• Georectifier
• Location wizard

See also wiki page which contains up-to-date information including screenshots.

For detailed information see the wxGUI manual page.

Layer Manager

Fig. 2: Layer Manager

Map Display Window

Fig. 3: Map Display

Vector digitizer

Fig. 4: Vector digitizer

Attribute Table Manager

• Browse attribute data of vector map, perform SQL select statements;
• Modify attribute data, insert new records to attribute table, delete existing records;
• Highlight selected items in Map Display Window;
• Extract selected items into new vector map;
• Modify attribute table - add, drop, rename columns;
• Modify vector map DB connection settings - add, remove or modify layers.

Fig. 5: Attribute Table Manager

References

1. Martin Landa: New GUI for GRASS GIS based on wxPython (GIS Ostrava 2008, January 27-30, 2008, Ostrava, Czech Republic)
2. Martin Landa, Cristina Moretto, Michele Zanolli, Luca Manganelli and Markus Neteler: wxPython GUI per GRASS (IX Meeting degli Utenti Italiani di GRASS - GFOSS, February 20-22, Perugia, Italy)

Appendix

SLOC statistics

SLOC    Directory       SLOC-by-Language (Sorted)
24247   gui_modules     python=24247
2486    vdigit          cpp=2486
1535    top_dir         python=1518,sh=17
792     nviz            cpp=792
750     compat          python=750
435     icons           python=435
141     scripts         sh=137,python=4
69      support         python=69
8       images          python=8
0       docs            (none)
0       xml             (none)

Totals grouped by language (dominant language first):
python:       27031 (88.73%)
cpp:           3278 (10.76%)
sh:             154 (0.51%)

Total Physical Source Lines of Code (SLOC)                = 30,463
Development Effort Estimate, Person-Years (Person-Months) = 7.23 (86.73)
 (Basic COCOMO model, Person-Months = 2.4 * (KSLOC**1.05))
Schedule Estimate, Years (Months)                         = 1.14 (13.63)
 (Basic COCOMO model, Months = 2.5 * (person-months**0.38))
Estimated Average Number of Developers (Effort/Schedule)  = 6.36
Total Estimated Cost to Develop                           = $ 976,344
 (average salary = $56,286/year, overhead = 2.40).
SLOCCount, Copyright (C) 2001-2004 David A. Wheeler
SLOCCount is Open Source Software/Free Software, licensed under the GNU GPL.
SLOCCount comes with ABSOLUTELY NO WARRANTY, and you are welcome to
redistribute it under certain conditions as specified by the GNU GPL license;
see the documentation for details.
Please credit this data as "generated using David A. Wheeler's 'SLOCCount'."
    

Developers

Fig. 6: wxGUI developers (August 2008)