NAME
Tie::Wx::Widget - implicit access value of a Wx widget
SYNOPSIS
use Tie::Wx::Widget;
tie $tiedwidget, Tie::Wx::Widget, $widget;
$tiedwidget = 7; # instead of $widgetref->SetValue(7);
say $tiedwidget; # instead of say $widgetref->GetValue;
untie $tiedwidget; # now $tiedwidget is a normal scalar again (not required)
CALLBACKS
Often are the widget values coupled with each other. For instance in App::Spirograph is a slider, which max value is the value of another slider. Once you know this, why keep track of it and change the range by hand any given time?
tie $tslider, Tie::Wx::Widget, $slider,
sub { $[0]->SetValue($[1]); $subslider->SetRange(1, $[1]) };
The first parameter to the callback is always the Wx object reference, the assign-callback gets also a second with the assigned value. Own callbacks replace the the ones, generated by default.
The complete parameter list is is:
tie $tw, Tie::Wx::Widget, $widget, [&$do_when_assign, &$do_when_retrieve];
Yes, its also doable with events, but thats also more syntax than this. Plus, its a different event for many widgets, why remember this? Plus, a tied widget still gives you the freedom to change the value under the radar. See section "INTERNALS" for more.
WARNINGS
Your program will die
, if you don't provide a proper Wx widget, that has a GetValue and SetValue method, or the callbacks are no coderef. Unless you init with:
use Tie::Wx::Widget 'warn_mode';
or do later:
Tie::Wx::Widget::warn_mode();
Then will be called warn
instead of die
. But you can switch anytime back with:
Tie::Wx::Widget::die_mode();
Wich has only effect for all variables tied afterwards. Because if the Wx ref is not good, there will be no tying anyway.
INTERNALS
# how to get a reference to the Tie::Wx::Widget object ?
$tieobject = tie $tiedwidget, Tie::Wx::Widget, $widget;
$tieobject = tied $tiedwidget;
# now you even can:
$tieobject->FETCH()
# aka:
$tieobject->{'widget'}->GetValue;
# or do any other method on the wx object
$tieobject->{'w'}->Show(0);
# works too (hides the widget)
$tieobject->STORE(7);
# doesn't do anything
$tieobject->DESTROY()
ACKNOWLEDGEMENTS
This was solely my idea before Linuxtag 2011. Started as a slide for my talk there.
AUTHOR
Herbert Breunung, <lichtkind at cpan.org>
LICENSE AND COPYRIGHT
Copyright 2011-2022 Herbert Breunung.
This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.
See http://dev.perl.org/licenses/ for more information.