wxPerl
Agile Cross-Platform GUI Development
(What I had to Learn the Hard Way)
Eric Wilhelm
Scratch Computing
http://scratchcomputing.com

wxPerl
bindings for wxWidgets GUI toolkit
●
multi-platform
●
native widgets
●
object-oriented
●
event driven
●

wxWidgets platforms
Win32
–
Mac OS X
–
GTK+
–
X11
–
Motif
–
WinCE
–
and more
–

Windows

Linux

Mac

Why Desktop Apps?
local machine resources
●
large files
–
soundcard
–
cpu
–
private data
●
encryption
●
airplanes
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Why Perl?
freedom from
●
static code
–
compilers
–
\"cross-platform reinvention of string
–
libraries\"
easier reuse
●
common (e.g. company-wide) modular
–
code
web apps
–
command-line apps
–

The “Wx” distribution (aka
wxPerl)
wraps wxWidgets in XS and some Perl
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332K tarball
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breakdown:
●
xs: ~21680 (57.42%)
perl: 8685 (23.00%)
cpp: 7395 (19.58%)
xsp: ~1662
note: SLOCCOUNT doesn't really speak XS
but very little documentation
●

Compare to WxGTK
(i.e. core+gtk port)
6.9M of C++ !
●
20x21k
cpp: 416710 (77.09%)
ansic: 112754 (20.86%)
sh: 10026 (1.85%)
python: 645 (0.12%)
lex: 194 (0.04%)
yacc: 128 (0.02%)
pascal: 74 (0.01%)
lisp: 6 (0.00%)
generated using David A. Wheeler's 'SLOCCount'

dotReader
open-source e-book reader in Perl
read, annotate, and search books
●
browse the web, send mail, etc
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shared annotations
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online/offline network fun
–
DRM (makes publishers happy)
●
flexible, environment-agnostic architecture
●
open source
●
plugins, plugins, plugins
●

dotReader details
today's raw numbers (Jun. 25th, 2007)
●
13K SLOC
98 modules + ~1200 line Build subclass
drop-in distributions
●
linux/qdos - PAR
–
mac - PerlWrapper + ExtUtils::MacMaker
–
embedded html widgets
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IE (activeX)
–
Webkit
–
Mozilla
–

Getting Started with wxPerl
Finding Documentation
wxPerl specific
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a slow wiki (somebody please make a US
–
mirror)
not much pod
–
some perlmonks stuff
–
demo directory
–
C++ documentation
●
C++ examples
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wxGlade
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Cross-platform Development
(aka fun with vnc)
svk and working copy on linux workstation
●
more and better tools
–
80% or more development is command-line
–
tests
●
● small utilities
● good discipline
● good for architecture
rsync+fam
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rdesktop/vnc to windows+cygwin
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vnc to mac
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Cross-platform Builds
automate
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automate
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automate
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Module::Build
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CPDK + remote ssh automation
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nightly builds
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cross-platform repackaging from linux
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Installation
(aka fun with make/nmake/bake/shake/quake)
Linux
●
debian (sarge, etch)
–
Windows
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camelpack + sourceforge PPMs
–
ExtUtils::FakeConfig
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Strawberry
–
Mac
●
xcode
–
cpan
–

wxGlade

BAD
code generation and why it is (maybe) a good idea
XRC (speed?)
●
segregate generated code
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have a consistent environment
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windows vs linux, glade versions
–
use version control!
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use subversion
–
have to make it be valid (strict) Perl
●
stupid regular expressions do the trick
–

Getting Past Getting Started
copy and paste is evil
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strive for deep clarity, not superficial
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don't ape glade
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don't ape C++
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don't even ape the examples
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Leaving “Getting Started”
Way Behind
modularity
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subclassing
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traits
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CMT / POE for responsiveness
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subprocesses
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discipline
●
as always, but particularly because we don't
–
have “best practices” in this realm yet

Eliminating Tabular Code
EVT_MENU( $self, 5007, sub {$_[0]­>activate_sidebar($_[1])});
EVT_MENU( $self, 5011, sub {$_[0]­>activate_reader($_[1])});
...
my $acc_table = Wx::AcceleratorTable­>new(
[0, WXK_F2, 5007, ], # activate sidebar
[0, WXK_F3, 5011, ], # activate widget
...
);
$self­>SetAcceleratorTable($acc_table);
my $acc_table = Wx::AcceleratorTable­>new(
map({$self­>_accel(@$_)}
['F2', sub {$_[0]­>activate_sidebar($_[1]);}],
['F3', sub {$_[0]­>activate_reader($_[1]); }],
...
),
);
$self­>SetAcceleratorTable($acc_table);

needs Perlin'
...
if($stroke =~ s/^(.*)\\+//) {
my $mk = 'wxACCEL_' . $1;
Wx­>can($mk) or croak(\"cannot find modifier key $mk\");
$mod = Wx­>$mk;
}
...
if($kl > 1) {
my $key_const = 'WXK_' . $key;
Wx­>can($key_const) or croak(\"cannot find key\");
$key = Wx­>$key_const;
}
else {
# it's a letter
$key = ord(uc($key));
}
my $id = Wx::NewId;
Wx::Event::EVT_MENU($self, $id, $subref);
return([$mod, $key, $id]);

More Perlification
can() doesn't work right
●
wxPerl::Constructors
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wxPerl::Styles
●
wxPerl::Lay_er_outer ???
●

What we really want is a
better wxGlade?
stealing ideas from smalltalk
●
(without losing unixness)
–
named objects and accessors
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DSL / YAML
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read + write and in-process dynamicism
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procedural / config-integration
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and/or code-snippet insertion?
●

Other Thoughts
menu introspection
● (WxPerl::MenuMaker)
event driven OOP
●
break into small pieces (e.g.
–
backend_file_open)
callbacks
●
closures
–
method calls
–
NOT \\&subname, please
–
accessors
●
Needs more Perlin' -- WxPerl/foo.pm
●

Wx::Perl/wxPerl Modules on
CPAN
wxPerl::Constructors
●
wxPerl::Styles
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Wx::Perl::Throbber
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Wx::Perl::ProcessStream
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Wx::Perl::Imagick
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Wx::TreeListCtrl
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Browser Widgets
wxMozilla / Wx::Mozilla
●
my eyes are bleeding!
–
Wx::WebKit
●
Wx::ActiveX
●
move along, nothing to see here
–
wxWebCore / Wx::WebCore
●
Apple's Objective-C experiment (take 2)
–
cross-platform
–
“The Future”
–

Logger
Log::Log4perl
●
dynamically configurable
–
init_and_watch
–
SIGHUP
–
insanely configurable
●
5 levels
–
any depth of 'class' hierarchy
–
levels are even implicit classes
–
don't get carried away here
–

wrap it
not
●
$logger = Log::Log4perl­>get_logger('blahblahblah');
$logger­>debug('foo');
just returns a singleton, so:
●
use dtRdr::Logger;
L - logging in caller() package
–
L­>debug('foo');
RL - arbitrary logging
–
trapping
●
$SIG{__WARN__}, logging to file
–
trapping $SIG{__DIE__} (popup)
–

Testing
./Build test
●
standard tests
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300 lines of custom test-support code
–
3200 5400 lines of regular tests
–
only 400 600 of that is gui
–
t/location 1
t 5
t/logger 2
t/_gui 9
t/multitask 3
t/annotation 8
t/plugins 3
t/book 34
t/range 1
t/config 4
t/search 3
t/_sync 5
t/toc 5
t/history 3
t/user 1
t/library 3

Building
make a custom Module::Build class
●
(not with a HEREdoc)
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Custom targets
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./Build par
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./Build starter_data
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./Build books
–
./Build binpush
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./Build bindistribute
–

Testing
./Build testall
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'test', 'testsync', and 'testgui'
–
./Build testgui
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is t/_gui/*.gt + Module::Build hack
–

Packaging and Deployment
Windows and Linux
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PAR
–
(Wx::ActiveX hack)
●
bundle the dlls, etc -- no dependencies for
●
user
a bit slow to rebuild
●
startup speed needs work here
●
Mac
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needs an AppBundle
–

PerlWrapper (Mac)
wxPerl (appbundle)
●
required to even get a working GUI
–
compiled with xcode, resource file, etc
–
automated tests work fine, but no focus
–
before click
PerlWrapper
●
a perl interpreter embedded in a compiled C
–
app
allows \"open myApp\" from command-line
–
ExtUtils::MacMaker
●
uh, no I don't run xcode on dos and linux
–

No really! Testing
./Build testgui
●
outside-in
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X11::GUITest
–
Win32::GuiTest
–
inside-out
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EVT_IDLE
–
Wx::Timer
–
DISPLAY=localhost:3 ./Build testall
–

Manual Testing
just hacks:
●
Ctrl+Shift+F5 does Module::Refresh
–
F7 quick window resize (to see console)
–
production stuff
●
Ctrl+L activate library pane
–
F2/F3 focus switch
–
command-line options or parameters
●
./run test_packages/foo/book.xml
–
dual-purpose tests
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perl -Ilib t/_gui/note_editor.gt foo
–

Acceptance Tests
ala data-driven testing
●
scripted manual verifications
●
automate actions as much as possible
●
still need better GUI test frameworks
●

Questions?

Thanks
scratchcomputing.com
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wxperl.sourceforge.net
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dotreader.com
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