#! /usr/bin/perl

# sleep for 2 minutes to allow chumby control panel boot-up
# this tries to guarantee that the current dim level has been written to "dimlevel"
sleep(2*60);

# get the current dimlevel
$dim_level = `cat /proc/sys/sense1/dimlevel`;
chop($dim_level);

# initialize toggle
$toggle = 2;

$x = 0;  # default coord
$y = 0;  # default coord

# wait for a good click event (one with x and y coordinates NOT 0)
while( ($x <= 0) ||
       ($y <= 0)     ) {

   $click = 0;    # no click yet
   $event = ""; # no event yet

   # look for a click  event
   $event = `head -1 /proc/chumby/touchscreen/coordinates | grep pen-down`;
   if( $event =~ /x=(\d+)\s+y=(\d+).*(pen-down)/) {
      $click = 1;
      $x = $1;
      $y = $2;
   } else {
      $x = 0;
      $y = 0;
   }

   # wait for no click event
   if( $click == 1 ) {
      $event = "";
      while( $event == "") {
         $event = `head -1 /proc/chumby/touchscreen/coordinates | grep pen-up`;
      }
      $click = 0; # click even is done
   }

   # upper-left ?
   if( ($x >  3600) &&
       ($y >  3600)    ) {  # toggle

      if($toggle == 2) {   # off
         system("echo 2 > /proc/sys/sense1/dimlevel");
         $toggle = 0;
      } else { # turn on at dimlevel

            # full on then dim; must do it this way
         system("echo 0          > /proc/sys/sense1/dimlevel");
         system("echo $dim_level > /proc/sys/sense1/dimlevel");

            # set up for next toggle
         $toggle = 2;
      }
   }
   $x = 0;
   $y = 0;

}