man pages section 3: Library Interfaces and Headers

Tk::Derived (3)

Name

Tk::Derived - Base class for widgets derived from others

Synopsis

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
}

Description

User Contributed Perl Documentation                                 Derived(3)



NAME
       Tk::Derived - Base class for widgets derived from others

SYNOPSIS
           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
          }

DESCRIPTION
       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.

       The derived class should normally override the "Populate" method
       provided by Tk::Derived and call "ConfigSpecs" to declare configure
       options.

       The public methods provided by Tk::Derived are as follows:

       ->ConfigSpecs(-key => [kind, name, Class, default], ...)


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+----------------------------+
       |ATTRIBUTE TYPE |      ATTRIBUTE VALUE       |
       +---------------+----------------------------+
       |Availability   | library/perl-5/perl-tk-532 |
       +---------------+----------------------------+
       |Stability      | Volatile                   |
       +---------------+----------------------------+

SEE ALSO
       Tk::ConfigSpecs Tk::mega Tk::composite



NOTES
       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       http://search.cpan.org/CPAN/authors/id/S/SR/SREZIC/Tk-804.036.tar.gz.

       Further information about this software can be found on the open source
       community website at http://search.cpan.org/~srezic/Tk.



perl v5.32.0                      2013-11-15                        Derived(3)