=for comment based on iup-3.5 - http://www.tecgraf.puc-rio.br/iup/en/elem/iupsubmenu.html
=head1 NAME
IUP::Submenu - [GUI element] menu item that, when selected, opens another menu
=head1 DESCRIPTION
Creates a menu item that, when selected, opens another menu.
=begin HTML
<p><img src="http://kmx.github.io/perl-iup/img-3.9/elem/iupsubmenu.png"></p>
=end HTML
=head1 USAGE
=head2 CREATION - new() method
$submenu = IUP::Submenu->new( TITLE=>"Name", child=>$menu_element );
B<child:> (named parameter) optional child menu reference. Can be C<undef> or ommited.
B<Returns:> the identifier of the created element, or C<undef> if an error occurs.
NOTE: You can pass to C<new()> other C<ATTRIBUTE=E<gt>'value'> or C<CALLBACKNAME=E<gt>\&func> pairs relevant
to this element - see L<IUP::Manual::02_Elements|IUP::Manual::02_Elements/"new()">.
=head2 ATTRIBUTES
For more info about concept of attributes (setting/getting values etc.)
see L<IUP::Manual::03_Attributes|IUP::Manual::03_Attributes>. Attributes specific to this element:
=over
=item B<IMAGE>
I<[Windows and GTK Only] (non inheritable)>
Image name of the
submenu image. In Windows, an item in a menu bar cannot have a check
mark. Ignored if submenu in a menu bar. A recommended size would be
16x16 to fit the image in the menu item. In Windows, if larger than the
check mark area it will be cropped.
=item L<TITLE|IUP::Manual::03_Attributes/TITLE>
I<(non inheritable)>
Submenu Text. The
"&" character can be used to define a mnemonic, the next character will
be used as key. Use "&&" to show the "&" character instead on defining
a mnemonic.
=item L<WID|IUP::Manual::03_Attributes/WID>
I<(non inheritable)>
In Windows, returns
the HMENU of the parent menu and it is actually created only when its
child menu is mapped.
=back
The following L<common attributes|IUP::Manual::03_Attributes/Common Attributes> are also accepted:
=over
=item * L<ACTIVE|IUP::Manual::03_Attributes/ACTIVE>
=back
=head2 CALLBACKS
For more info about concept of callbacks (setting callback handlers etc.)
see L<IUP::Manual::04_Callbacks|IUP::Manual::04_Callbacks>. Callbacks specific to this element:
=over
=item L<HIGHLIGHT_CB|IUP::Manual::04_Callbacks/HIGHLIGHT_CB>
Action generated when the submenu is highlighted.
=back
The following L<common callbacks|IUP::Manual::04_Callbacks/Common Callbacks> are also accepted:
=over
=item * L<MAP_CB|IUP::Manual::04_Callbacks/MAP_CB>, L<UNMAP_CB|IUP::Manual::04_Callbacks/UNMAP_CB>
=back
=head1 NOTES
In Motif and GTK, the text font will be affected by the dialog font
when the menu is mapped.
=head1 EXAMPLES
The element B<IUP::Submenu> is used in the following sample scripts:
=over
=item * L<0-basic/dialog2.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/0-basic/dialog2.pl> - IUP::Dialog example
=item * L<0-basic/item.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/0-basic/item.pl> - IUP::Item Example
=item * L<0-basic/layoutdialog.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/0-basic/layoutdialog.pl> - IUP::LayoutDialog example
=item * L<0-basic/menu.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/0-basic/menu.pl> - IUP::Menu example
=item * L<0-basic/separator.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/0-basic/separator.pl> - IUP::Separator example
=item * L<0-basic/submenu.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/0-basic/submenu.pl> - IUP::Submenu example
=item * L<1-apps/app-mdi.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/1-apps/app-mdi.pl> - IUP app example
=item * L<1-apps/app-sample1.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/1-apps/app-sample1.pl> - example used for screenshot - IUP.pod
=item * L<1-apps/app-sample2.pl|https://metacpan.org/source/KMX/IUP-0.303/examples/1-apps/app-sample2.pl> - example based on the original sample.c
=back
=head1 SEE ALSO
L<IUP::Item|IUP::Item>, L<IUP::Separator|IUP::Separator>, L<IUP::Menu|IUP::Menu>
The original doc: L<iupsubmenu.html|http://www.tecgraf.puc-rio.br/iup/en/elem/iupsubmenu.html>
=cut