Mastering Perl/Tk

Experimenting with Fonts

You don’t generally want to hardcode font specifications in your programs. Simply put, it prevents your users from customizing your applications. There are extenuating circumstances, though; you might have an HP calculator that has a specific look that shouldn’t be changed (see Chapter 15). Creating such a specific look might require one or more particular fonts.

One way to determine what font to use is to write a program using the fontFamilies method that displays various font specifications. So, before we get into the details of creating a font definition, let’s look at a program that lets us play around with the fonts on our system. This program is useful no matter what operating system you’re on.

use Tk; use Tk::BrowseEntry; use strict; my $mw = MainWindow->new(-title => 'Font Viewer'); my $f = $mw->Frame->pack(-side => 'top'); my $family = 'Courier'; my $be = $f->BrowseEntry(-label => 'Family:', -variable => \$family, -browsecmd => \&apply_font)->pack(-fill => 'x', -side => 'left'); $be->insert('end', sort $mw->fontFamilies); my $size = 24; my $bentry = $f->BrowseEntry(-label => 'Size:', -variable => \$size, -browsecmd => \&apply_font)->pack(-side => 'left'); $bentry->insert('end', (3 .. 32)); my $weight = 'normal'; $f->Checkbutton(-onvalue => 'bold', -offvalue => 'normal', -text => 'Weight', -variable => \$weight, -command => \&apply_font)->pack(-side => 'left'); my $slant = 'roman'; $f->Checkbutton(-onvalue => 'italic', -offvalue => 'roman', -text ...