gistfile1.txt

# vim:ft=perl:et:
# # change background color when focus lost/gained
use strict;
use warnings;
use Time::HiRes qw(usleep);


# NOTE: Default xterm/iTerm2 enable/disable: CSI ? 1004 h/l
#   e.g.: <Esc>[?1004l / <Esc>[?1004h

# ENABLE:  echo -ne "\033]777;focus;on\007"
# DISABLE: echo -ne "\033]777;focus;off\007"

# Escape sequences could be custom, like:
# my $csi_in = "\033[UlFocusIn";
# my $csi_out = "\033[UlFocusOut";

my $csi_in =  "\033]11;#ffff00\007";
my $csi_out = "\033]11;#ff0000\007";

sub on_start {
    my($self) = @_;
    $self->{focus_activated} = 0;
    $self->{has_focus} = 0;
}

sub on_osc_seq_perl {
	my ($self, $osc, $resp) = @_;

	# Only act on the "\033]777;focus;XXX\007" sequence
	return unless $osc =~ s/^focus;//;
	# Note the subscription/unsubscription
	$self->{focus_activated} = $osc eq 'on' ? 1 : 0;
	# If subscribed and the terminal has focus, send first focus event to the program
	if (($self->{focus_activated}) && ($self->{has_focus})) {
		usleep(16000);
		$self->tt_write($csi_in);
	}
}

sub on_focus_in {
    my($self) = @_;
    $self->{has_focus} = 1;
    if ($self->{focus_activated}) {
        # Delay this event 16 ms, so it is after the focus_out from the previous window.
        usleep(16000);
        $self->tt_write($csi_in);
    }
}

sub on_focus_out {
    my($self) = @_;
    $self->{has_focus} = 0;
    if ($self->{focus_activated}) {
        $self->tt_write($csi_out);
    }
}