This enumeration specifies the property types of effects which can be used.
enum {
SCREEN_FLIP_AXIS = 1
SCREEN_FLIP_DIRECTION = 2
SCREEN_ROTATE_DIRECTION = 10
SCREEN_PAGE_CURL_ORIGIN = 20
SCREEN_PAGE_CURL_POSITION = 21
SCREEN_REVEAL_ORIGIN = 30
SCREEN_REVEAL_POSITION = 31
};