Perl modules to get a GUI up in minutes. The world's easiest GUI Designer....GUIDeFATE

1. Quick and Dirty GUI Applications
(and why you should make them)
Saif Ahmed (SAIFTYNET)

2. Saif Ahmed
Orthopaedic Surgeon
Interests include:-
(Tissue Engineering)
(Electronics)
(Robotics)
(Programming)
Introduction

3. %Contents=(
Context => "Brief insight into TE", # Tissue Engineering n=5
GUIDeFATE => "Quick and dirty GUI" , # One way to do it n=18
SIMPLE => "End-user = Developer",# If there is time n=2
Soapbox => "Putting world right" , # Old fart talk n=2
Conclusion => undef,
);

4. Context

5. Tissue Engineering
Organisms are made of many organs, made of
many tissues, made of many cells supported
by matrices.
Living structures are made of tissues...a
structure made of cells and a scaffold holding
them together.
Cells need oxygen, nutrients and electrolytes to
function delivered by a perfusion system
So mixing cells, matrix and a blood supply
produces living tissue….simple, eh?

6. Brief Overview of How Others Do It
Tissue culture is easy: Organ culture is difficult
In an organ diverse specialised cells are
distributed in geographically distinct locations in
a matrix providing mechanical support, in a
biologically well maintained and perfused
environment.
Bioprinters exist. Expensive, proprietary, do not
work.
Generated tissue needs to be kept in a sterile
climate controlled environment.
Usually the entire printing device integrates with
the build environment

7. The IntraCavity Bio Matrix 3D Printer.
Open Source 3D printer capable of constructing
a living tissue engineered inside a cavity within a
narrow neck. Cheap, novel, reduced
dependencies
Most parts 3D printed
To be driven using a Perl application:-
● Convert raster shape to vector voxels
● Translate polar geometry into cartesian
coordinates for Extruder positioning
● Control flow rate and composition
● Generate the G-code and upload
...via a Real-Time embedded system for
actuator control (like conventional Desktop 3d
printers)
(Help wanted)

8. The software interface
The positioning electronics and the
hardware=easy, doable, being refined.
Control software objectives : -
● Usable interface for non-programmers
○ Everybody want applications to “just
work”
● Abstraction and Algorithmic transformation
● Motion simulation
● Decomposition of printer mechanical
actions
● G-Code generation
● Testing with final device

9. Visualisation is critical for 3D development
Need to be able to simulate motion to make
sure algorithms are right
Need to visualise that motion
Need End-user to be able make fine
adjustments without reprogramming
Need to make the tools accessible
for non programmers
Need to make it programmable for
non-programmers
Need to learn A Lot Of Things...
….but I AM OLD

10. Diversion into Interface Development
by a naive developer

11. Making Perl GUI Applications
Modules exist for multiple desktop interfaces
Wx, Multiplatform,
QT4 (not installable from CPAN)
GTK
Win32 (Platform constrained)
Tk (Dated looks)
Design tools exist to make things less complicated:
e.g. wxGlade, Glade, Qt designer. Each only work
with one interface, each with a significant learning
curve.
BUT it isn’t as easy as it should be
“Wx not easily installable in some systems, and
in versions of Perl after 5.16”
“QT5 depends on Perl to build, but does not
provide Perl API”
“Tk works but looks ugly”
“Use Inline Python for a GUI in Perl”
“Info on Perl GUI development is illusive or old”

12. Too much effort, too much to learn
I tried...
Too many Toolkits (wx, Tk, Qt, etc)
Too many paradigms for interacting with GUI
Too many widget types
Too many options for each widget type
Even if it works on one platform, no assurance it
will work for others...dependencies can not
always be met.
Diversity of platform and interface
makes it easier to avoid the
Desktop altogether
… back to the drawing board

13. How I do it
...it is probably not the best way to
do things
...it is one way to do things
...it may not work for everybody
...it may be coded better
Invitation to constructively criticise
Why I did it this way
Do not have surplus time and energy
Fading memory and learning capacity
Others need to read/adapt my code
Apps to be usable by non-coders
TIMTOWDI

14. Graphical User Interface Design From A Text Editor
+-------------------------------------------+
|T The Plants List App |
+M------------------------------------------+
| {Refresh Data} dd/mm/yy |
| [ ] {Search} |
| {Angiosperms } 000 {Gymnosperms} 000 |
| {Pteridophytes} 000 {Bryophytes } 000 |
| No item on list |
| +T-----------------+ +I--------------+ |
| | | | | |
| | | | | |
| | | | | |
| | | | | |
| | | | | |
| +------------------+ +---------------+ |
| {<} { Explore } {>} { Upload Photo } |
| 0000 of 0000 |
| www.theplantlist.org wikipedia.org |
+-------------------------------------------+
Perl is good at parsing textual data

15. GUIDeFATE-
the world simplest GUI designer
Design Specifications
● No tools = Nothing external to learn
● Backend agnostic = Users choose what
toolkit is installed or can be installed.
Platform unconstrained
● Visual development = easy for a newbie
● Embedded = visible in the program code
● Few widgets = sacrifice capability for
convenience
Downside...programmed by an amateur

16. Designed in a Text Editor
use GUIDeFATE;
# create textual representation
my $window=<<END;
+----------------+
|T Window Title |
+----------------+
| |
| Hello World |
| |
+----------------+
END
# Convert to a GUI and then start it
my $gui=GUIDeFATE->new($window);
$gui->MainLoop;
The window design is obvious from the code in
monospace font
Looks roughly similar in multiple backends
Supports Wx, Qt, GTK, TK, Win32, HTML

17. Only one object….the GUI Frame
GUIDeFATE.pm
● Imports frame object from GFwx, GFtk etc
● Parses textual representation: convert()
○ To create a list discovered widgets
○ Allocate sequential Internal IDs
○ Add these objects to the frame
○ Optionally generate developer assistance
● Return the Frame object
if ((!$target)||($target=~/^wx/i)){
$target="wx";
die "Failed to load Wx backend: $@"
unless eval {require GFwx} ;
GFwx->import;
convert($textGUI,$assist);
return GFwx->new();
}
The Frame Object is defined in GFWx, GFtk etc
Offers only a few methods: -
● Set, get and append values
● Open file selector and dialog box
● MainLoop
Invocation
my $gui=GUIDeFATE->new($window,$backend,$assist);
my $frame=$gui->getFrame|| $gui;
$gui->MainLoop;

18. Options
my $gui=GUIDeFATE->new($window,$backend,$assist);
$window contains the textual representation string
$backend (optional) contains one of “wx”, “gtk”, “qt”, “tk”,
(“html” or “web” experimental options exist as well)
$assist (optional) contains one of :
● “q” for quiet…(default),
● “v” for verbose...prints to console each widget
identified…
● ”a” for autogenerate… generates a perl - file containing
a list of empty subroutines, referring to functions called
for user interaction

19. Another example GUI string
+------------------------+
|T Calculator |
+M-----------------------+
| [ ] |
| {sqr}{pi }{ C }{AC } |
| { 1 }{ 2 }{ 3 }{ + } |
| { 4 }{ 5 }{ 6 }{ - } |
| { 7 }{ 8 }{ 9 }{ * } |
| { . }{ 0 }{ = }{ / } |
| made with GUIdeFATE |
| and happy things |
+------------------------+

20. Other widgets…(very few widgets currently, more may eventually follow)
Buttons {label}
Input box [default text]
Combobox ^combo^
ImageBox +I-----------+
|Image.path |
| |
| |
| |
+------------+
TextArea +T-----------+
|content |
| |
| |
| |
+------------+

21. Example...Logo to SVG convertor
my $window=<<END;
+------------------------------------------------------------------------------+
|T LOGO to SVG convertor |
+M-----------------------------------------------------------------------------+
|{Draw}{Logs} {Zoom in }{Zoom out}{Zoom All}{<}{^}{v}{>}{Center all}{AC}{Reset}|
|+T---------------------++I---------------------------------------------------+|
||# Simple Logo ||simplelogo.svg ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|| || ||
|+----------------------+| ||
|[ ]+----------------------------------------------------+|
+------------------------------------------------------------------------------+
Menu
-File
--New
--Open
--Save Script
--Quit
-Image36
--Draw
--Save SVG
--Save PNG
-Examples
--Star
--Spiral
--Flower
--About
END

22. Example...A Simple Game
my $window=<<END;
+------------------------------------------------+
|T Rock Paper Scissors Lizard Spock |
+------------------------------------------------+
| |
| Play Rock Paper +I------+ |
| Scissors Lizard |rock.bm| |
| Spock. Click |p | |
| any button to +-------+ |
| play { Rock } |
| |
| +I------+ +I------+ |
| |Spock.j| +I------+ |paper.j| |
| |pg | |sister.| |pg | |
| +-------+ |jpg | +-------+ |
| { Spock } +-------+ { Paper } |
| I am ready |
| |
| +I------+ +I------+ |
| |Lizard.| |scissor| |
| |jpg | |s.jpg | |
| +-------+ +-------+ |
| {Lizard } {Scissrs} |
| |
+------------------------------------------------+
END

23. Example...The Executioner
my $window=<<END;
+--------------------------------------+
|T Executioner |
+M-------------------------------------+
| ^bends ^ Options ^optns^ |
| {Calculator } |
| {Rock Paper Scissors Lizard Spock} |
| {GUI Gnuplotter } |
| { Text editor } |
| {Image Magick GUI } |
| { Executioner (this) } |
| [ ]{Execute } |
+--------------------------------------+
bends=$backends
optns=Quiet,Verbose,Assist,Debug
END

24. Convert to a Web Application?
my $gui=GUIDeFATE->new($window, “web”);

25. Convert something useful into easily usable
e.g. GUI interface for Gnuplot or
ImageMagick
Can create an interface with an editor
panel
Include help and example in the menu
Load, Edit, Save, Export etc without
needing console

26. Duck-tape the Internet to the Desktop
Connect to Internet Databases and harvests
data and present to the user as needed.
This searches all known plants from
ThePlantList.org creating a local cache, then
searches wikipedia for the plants and if an
image found, saves a copy

27. The Transformative Effect of Adding a Desktop GUI
● Transforms workflow
● Immediate visual feedback of yields
● Able to identify needs and address wishlist
quickly
● Using a instant GUI frees programming
time to enhance your utility rather than
focus on the interface
● Can make legacy console applications
interact with a modern UI
The web browser has been Perl’s principle GUI.
Not appropriate for all scenarios
Unnecessarily narrows scope
Screenshot application

28. End-user Programmability

29. Simple Integratable Modular Programming Language Experiment
● Customisable sequential task
processing from a script.
● Generate visual output, simulating
programmed motion
● Don’t know graphics programming
○ but can understand SVG
○ → SimpleLOGO
● Able to display code, outputs, and
debugging information on GUI
● Perl makes script parsing easy

30. Soap Box - Vanishing Languages
Goal of Perl "to make the easy things easy, and the hard things possible" (1)
“the power of a programming language
is not what it lets you do, but what it lets you do easily” (2)
Larry Wall

31. “When I were a lad...”
Perl is clearly good language for
● Command line tools
● Sysadmin tools
● CGI, Webapps
● Bioinformatics
● (? Desktop utilities)
Learn a system, and code it, all the tricks and
nuances, etc
Admire skills of fellow coders
Do a few snippets of code
Feel good about yourself
Which later becomes obsolete…
But Perl seemed, no IS, different...

32. Perl Super Powers
● CPAN Modules for every task
● Text processing and RegExp power
● Performance
● One-liners
● Do more with fewer lines of code
Paradox...
Perl utilities often serve large numbers of people
behind other more visible interfaces
Webapps, websites, server management etc
Being robust, reliable and low maintenance, the work
is invisible
Invisible Power Tends to Vanish (and no-one notices)

33. Make Perl Applications Visible- Use a GUI
Accessibility
Usefulness
Simplicity
Intuitiveness
Modern interface paradigms
Sensory stimulus (Multimedia yields)
Unconstrained by OS, Graphical Toolkit or
network
So … Make Desktop Perl applications

34. Conclusion
It is not enough for a programming language to make hard things possible,
Hard things should be made easy too…
It is not enough for a program to be usable by its developer
Usefulness is defined by the effort required of any user
to reach a desired result
Concentrating on niche server-side, headless and console bound operations limits
a language or an application. It should not be difficult to expand scope of any
application to be delivered from the Desktop as well.