#!/usr/bin/perl

# Perl extension to resize the terminal.
sub on_user_command {
  my ($self, $cmd) = @_;

  # Get existing fontset, something like:
  # xft:DejaVu Sans Mono:pixelsize=12:aspect=0.9,xft:AR PL Uming HK
  my $fontset = $self->{term}->resource("font");
  my @fonts = split /,/, $fontset;
  my @new = ();

  # Split into individual font definitions.
  foreach my $font (@fonts) {
    if ($font =~ /:pixelsize=(\d+)/) {
      my $size = $1;
      my $adjusted = $size;

      # Rewrite the font definition to be resized.
      if ($cmd =~ /:bigger/) { $adjusted++ }
      elsif ($cmd =~ /:smaller/) { $adjusted-- }

      $adjusted = 1 if $adjusted < 1;
      $font =~ s/:pixelsize=$size/:pixelsize=$adjusted/;
    }

    push @new, $font;
  }

  # Set the new fontset.  Just putting the resource doesn't work so
  # use an escape sequence.
  $fontset = join(",", @new);
  $self->{term}->cmd_parse("\033]50;$fontset\007");
}