isCommandKeyPressed.js

// Exciting globals!!!
var getIsACommandKeyDown = function () {
  return IS_RIGHT_COMMAND_KEY_PRESSED || IS_LEFT_COMMAND_KEY_PRESSED;
};

var IS_LEFT_COMMAND_KEY_PRESSED;
var IS_RIGHT_COMMAND_KEY_PRESSED;

$(window).keydown(function (e) {
  var theKeyThatIsDown = e.keyCode;
  if (theKeyThatIsDown === 93) IS_RIGHT_COMMAND_KEY_PRESSED = true;
  if (theKeyThatIsDown === 91) IS_LEFT_COMMAND_KEY_PRESSED = true;
});

$(window).keyup(function (e) {
  var theKeyThatIsDown = e.keyCode;
  if (theKeyThatIsDown === 93) IS_RIGHT_COMMAND_KEY_PRESSED = false;
  if (theKeyThatIsDown === 91) IS_LEFT_COMMAND_KEY_PRESSED = false;
})