Perl and GUI. Work with the menu

Overview of Tk widgets, I will start by reviewing the main menu taking into account the features of various OSs.

First, create a blank for our application:

#! / usr / bin / perl -w
use strict;
use Tkx;
our $ PROGNAME = 'app';
our $ VERSION = '0.1';

my $ windowingsystem = Tkx :: tk_windowingsystem ();
my $ IS_AQUA = ($ windowingsystem eq 'aqua');
# Given that the names of some buttons may vary, 
# in OSX this is Control, in Win / X11 it's Ctrl, add a few more variables
# (useful for hotkeys)
my $ plat_acc_ctrl = ($ ^ O eq 'darwin')? ('Control-'): ('Ctrl +');
my $ plat_evt_ctrl = ($ ^ O eq 'darwin')? ('Control-'): ('Control-');
# Main window.
my $ mw = Tkx :: widget-> new ('.');
Tkx :: tk (appname => $ PROGNAME);
Tkx :: wm_minsize ($ mw => qw (320,200));
# a new menu is attached using the -menu option
$ mw-> configure (
  -menu => make_menu ($ mw),
);
Tkx :: MainLoop;
1;
sub on_quit {
  Tkx :: tk ___ messageBox (-message => 'Goodbye;]');
  exit
}
sub show_about {
  Tkx :: tk ___ messageBox (-message => "$ PROGNAME $ VERSION");
}
sub make_menu {
 my $ mw = shift || return
 # By default, all menus look similar in GIMP, they can be detached
 # Therefore, turn off this option
 Tkx :: option_add ('* Menu.tearOff', 0)
 # ... continued below
  return $ m; 
}

Everything is as usual, File, Edit, Help. (cascading menu). A new object is created using the new_menu () method; (like a container)

my $ m = $ mw-> new_menu (); # Top level
my $ fm = $ m-> new_menu (); # File
my $ em = $ m-> new_menu (); # Edit
# Now, add our items to the top level
$ m-> add_cascade (-label => 'File', -menu => $ fm, -underline => 0);
$ m-> add_cascade (-label => 'Edit', -menu => $ em, -underline => 0);

Adding is done through add_cascade (), where
-label is the menu title.
-menu - widget
-underline - underscore letter index. It is necessary for quick navigation using the Alt button + letter (numbering goes from 0),

we look at what happened.


There is no sense from an empty menu, so we’ll “stuff” it with commands

# File menu
$ fm-> add_command (
  -label => 'Do something',
  -underline => 0,
  -command => sub {},
);
# delimiter
$ fm-> add_separator ();
$ fm-> add_command (
  -label => 'Quit',
  -underline => 0,
  -accelerator => "$ {plat_acc_ctrl} Q",
  -command => [\ & on_quit],
);
Tkx :: bind (all => "<$ {plat_evt_ctrl} q>" => [\ & on_quit]);
# Edit menu
$ em-> add_command (
  -label => 'Cut',
  -underline => 2,
  -accelerator => "$ {plat_acc_ctrl} X",
  -command => sub {Tkx :: event_generate (Tkx :: focus (), '<habracut> ')},
);
$ em-> add_command (
  -label => 'Copy',
  -underline => 0,
  -accelerator => "$ {plat_acc_ctrl} C",
  -command => sub {Tkx :: event_generate (Tkx :: focus (), '<> ')},
);
$ em-> add_command (
-label => 'Paste',
-underline => 0,
-accelerator => "$ {plat_acc_ctrl} V",
-command => sub {Tkx :: event_generate (Tkx :: focus (), '<> ')},
);

On Quit, we made a hotkey (Ctrl + Q) using the bind method.
To indicate an “accelerator”, -accelerator is used , and when the event is pressed, the -command
command accepts a pointer to a subprogram, and if you need to pass parameters to it, then we use the anonymous array
[\ & function, parameter1, parameter2]

File, Edit is. Remained item - Help.

X11 has its own system name ( 'help' ) for the Help item. OSX also has a 'apple' menu .
Given this:

my $ hname = ($ IS_AQUA? 'nothelp': 'help');
my $ hm = $ m-> new_menu (-name => $ hname);
$ m-> add_cascade (
  -label => 'Help',
  -menu => $ hm,
  -underline => 0,
);
# .. add help, homepage, etc.
if (! $ IS_AQUA) {
  $ hm-> add_command (
    -label => 'About',
    -underline => 0,
    -command => [\ & show_about],
  );
} else {
   my $ apple_menu = $ m-> new_menu (-name => 'apple');
   $ m-> add_cascade (
     -label => $ PROGNAME,
     -menu => $ apple_menu,
   );
   $ m-> add_command (
     -label => "About $ PROGNAME",
     -command => [\ & show_about],
   );
}

I will add screenshots with Linux / OSX later.