Tk::Derived - Base class for widgets derived from others
package Tk::MyNewWidget; use Tk::widgets qw/ BaseWidget, list of Tk widgets /; use base qw/ Tk::Derived Tk::BaseWidget /; Construct Tk::Widget 'MyNewWidget'; sub ClassInit { my( $class, $mw ) = @_; #... e.g., class bindings here ... $class->SUPER::ClassInit( $mw ); } sub Populate { my( $self, $args ) = @_; my $flag = delete $args->{-flag}; if( defined $flag ) { # handle -flag => xxx which can only be done at create # time the delete above ensures that new() does not try # and do $self->configure( -flag => xxx ); } $self->SUPER::Populate( $args ); $self = $self->Component( ... ); $self->Delegates( ... ); $self->ConfigSpecs( '-cursor' => [ SELF, 'cursor', 'Cursor', undef ], '-something' => [ METHOD, dbName, dbClass, default ], '-text' => [ $label, dbName, dbClass, default ], '-heading' => [ {-text => $head}, heading, Heading, 'My Heading' ], ); } sub something { my( $self, $value) = @_; if ( @_ > 1 ) { # set it } return # current value }
Tk::Derived is used with Perl's multiple inheritance to override some methods normally inherited from Tk::Widget.
Tk::Derived should precede any Tk widgets in the class's base class definition.
Tk::Derived's main purpose is to apply wrappers to configure and cget methods of widgets to allow the derived widget to add to or modify behaviour of the configure options supported by the base widget.
configure
cget
The derived class should normally override the Populate method provided by Tk::Derived and call ConfigSpecs to declare configure options.
Populate
ConfigSpecs
The public methods provided by Tk::Derived are as follows:
Tk::ConfigSpecs Tk::mega Tk::composite
To install Tk, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Tk
CPAN shell
perl -MCPAN -e shell install Tk
For more information on module installation, please visit the detailed CPAN module installation guide.