#!/usr/bin/perl -w

# scale: Front-end to changing the AppleDisplayScaleFactor, for Hackintosh
# on netbooks where the screen resolution isn't tall enough for some windows.
#
# Set the scale factor for the session:
#  scale 0.8
#  !!! Remember to set it back to 1.0 when you're done !!!
#
# Set the scale just to launch a specific app, then set it back:
#  scale 0.8 "Photo Booth"
#  scale 0.8 /Applications/Photo\ Booth.app
#
# --Kirsle
# http://sh.kirsle.net/

unless (@ARGV) {
	print "usage: scale <aspect-ratio> [app]\n"
		. "ex: scale 0.8\n"
		. "    scale 0.8 /Applications/Photo\\ Booth.app\n"
		. "    scale 0.8 'Photo Booth'\n";
	exit(1);
}
my $scale = shift(@ARGV);
if ($scale =~ /[^0-9\.]/) {
	die "Scale factor must be a number!";
}
my $app = undef;
if (scalar(@ARGV)) {
	$app = shift(@ARGV);
	if (!-e $app) {
		# Try a full path (e.g. Photo Booth -> /Applications/Photo Booth.app)
		$app = "/Applications/$app.app";
		if (!-e $app) {
			die "Can't find $app: no such file.";
		}
	}
}

# set the scale
system("defaults write -g AppleDisplayScaleFactor $scale");

# launching an app too?
if (defined $app) {
	system("open \"$app\"");
	system("defaults write -g AppleDisplayScaleFactor 1.0");
	print "$app launched with scale ratio of $scale\n";
	exit(0);
}
else {
	if (int($scale) != 1) {
		print "Scale set to $scale for the session. Be sure to "
			. "reset it to 1.0 when you're done!\n";
		exit(0);
	}
}