/**
* Handles the key down of a keyboard modifier
*
* @param string $modifier The modifier to handle (see self::MODIFIER_*)
*/
protected function keyDownModifier($modifier)
{
switch ($modifier) {
case self::MODIFIER_CTRL:
throw new UnsupportedDriverActionException('Ctrl key is not supported by %s', $this);
case self::MODIFIER_ALT:
$this->browser->altKeyDown();
break;
case self::MODIFIER_SHIFT:
$this->browser->shiftKeyDown();
break;
case self::MODIFIER_META:
$this->browser->metaKeyDown();
break;
}
}