Perl Cookbook

Creating Menus with Tk

Problem

You want to create a window that has a menu bar at the top.

Solution

Use the Tk Menubutton and Frame widgets:

use Tk;

$main = MainWindow->new();

# Create a horizontal space at the top of the window for the
# menu to live in.
$menubar = $main->Frame(-relief              => "raised",
                        -borderwidth         => 2)
                ->pack (-anchor              => "nw",
                        -fill                => "x");

# Create a button labeled "File" that brings up a menu
$file_menu = $menubar->Menubutton(-text      => "File",
                                  -underline => 1)
                     ->pack      (-side      => "left" );
# Create entries in the "File" menu
$file_menu->command(-label   => "Print",
                    -command => \&Print);

This is considerably easier if you use the -menuitems shortcut:

$file_menu = $menubar->Menubutton(-text     	=> "File",
                                 -underline 	=> 1,
                                 -menuitems 	=> [
              [ Button => "Print",-command  	=> \&Print ],
               [ Button => "Save",-command  	=> \&Save  ] ])
                           ->pack(-side     	=> "left");

Discussion

Menus in applications can be viewed as four separate components working together: Frames, Menubuttons, Menus, and Menu Entries. The Frame is the horizontal bar at the top of the window that the menu resides in (the menubar). Inside the Frame are a set of Menubuttons, corresponding to Menus: File, Edit, Format, Buffers, and so on. When the user clicks on a Menubutton, the Menubutton brings up the corresponding Menu, a vertically arranged list of Menu Entries.

Options on a Menu are labels (Open, for example) or separators (horizontal lines dividing one set of entries from another in a single menu).

The command entry, like Print ...