Added hdmi_toggle.pl helper script

hdmi_toggle.pl

@@ -0,0 +1,88 @@
+#!/usr/bin/perl
+# hotplug script that toggles laptop' secondary display to be right of embedded one
+
+use strict;
+use warnings "all";
+
+use Fcntl;
+
+my $XRANDR = `xrandr`;
+
+if ( $? != 0 ) {
+	exit 1;
+}
+
+my @connected = grep {/ connected /} split(/\n/, $XRANDR);
+
+if (@connected > 2) {
+	print "Assume that we have no more than 2 displays: one in lid and one external";
+	exit 1;
+}
+
+my @disconnected = grep {/ disconnected \d/} split(/\n/, $XRANDR);
+my $config = (split(/\n/, $XRANDR, 2))[0];
+my $vscreenWidth = (split(/\s/, $config))[7];
+my $sumOfDisplaysWidth = 0;
+
+my $restart = 0;
+
+# this loop required to disable disconnected but not disabled display
+do {
+	# if we detect disconnected display that is not not yet disabled, we disable it and
+	# on one more iteration we need to update displays list
+	if ($restart == 1) {
+		$XRANDR = `xrandr`;
+		@connected = -1;
+		@connected = grep {/ connected /} split(/\n/, $XRANDR);
+		@disconnected = grep {/ disconnected \d/} split(/\n/, $XRANDR);
+	}
+
+	$restart = 0;
+
+	foreach my $d (@connected) {
+		my $param = (split(/ /, $d))[2];
+
+		# display disconnected but not disabled
+		if ((split(/x/, $param, 2))[0] eq '(normal') {
+			my $display = (split(/ /, $d, 2))[0];
+			`xrandr --output $display --auto`;
+			sleep 2;
+			$sumOfDisplaysWidth = 0;
+			$restart = 1;
+			last;
+		}
+
+		$sumOfDisplaysWidth += (split(/x/, $param, 2))[0];
+	}
+} while ($restart == 1);
+
+# no changes, just quit
+if ($vscreenWidth == $sumOfDisplaysWidth) {
+	exit 0;
+}
+
+my $embeddedDisplay = '';
+my $externalDisplay = '';
+
+foreach my $d (@connected) {
+	my $display = (split(/ /, $d, 2))[0];
+
+	if ($display =~ /^e/) {
+		$embeddedDisplay = $display;
+	} else {
+		$externalDisplay = $display;
+	}
+}
+
+if ($externalDisplay eq '') {
+	$externalDisplay = (split(/ /, $disconnected[0], 2))[0];
+}
+
+if ($vscreenWidth > $sumOfDisplaysWidth) {
+	`xrandr --output $externalDisplay --off`;
+} elsif ($vscreenWidth < $sumOfDisplaysWidth) {
+	`xrandr --output $externalDisplay --auto --right-of $embeddedDisplay`;
+}
+
+exit 0;
+