module PDF.Content.Operator.Text (
      Operator(..)
    , signature
  ) where

import PDF.Content.Operator.Common (Signature)
import PDF.Object (DirectObject(..))

data Operator =
    Td | TD | Tm | Tstar -- text positioning
  | TJ | Tj | Quote | DQuote -- text showing
  | Tc | Tw | Tz | TL | Tf | Tr | Ts -- text state
  deriving (Bounded, Enum, Show)

signature :: [Signature Operator]
signature = [
      (Td, \l -> case l of [_, _] -> True ; _ -> False)
    , (TD, \l -> case l of [_, _] -> True ; _ -> False)
    , (Tm, \l -> case l of [_, _, _, _, _, _] -> True ; _ -> False)
    , (Tstar, \l -> case l of [] -> True ; _ -> False)
    , (TJ, \l -> case l of [Array _] -> True ; _ -> False)
    , (Tj, \l -> case l of [StringObject _] -> True ; _ -> False)
    , (Quote, \l -> case l of [StringObject _] -> True ; _ -> False)
    , (DQuote, \l -> case l of [StringObject _] -> True ; _ -> False)
    , (Tc, \l -> case l of [_] -> True ; _ -> False)
    , (Tw, \l -> case l of [_] -> True ; _ -> False)
    , (Tz, \l -> case l of [_] -> True ; _ -> False)
    , (TL, \l -> case l of [_] -> True ; _ -> False)
    , (Tf, \l -> case l of [NameObject _, _] -> True ; _ -> False)
    , (Tr, \l -> case l of [_] -> True ; _ -> False)
    , (Ts, \l -> case l of [_] -> True ; _ -> False)
  ]