Atom.hs


{- |
Copyright  : Will Thompson, Iñaki García Etxebarria and Jonas Platte
License    : LGPL-2.1
Maintainer : Iñaki García Etxebarria (inaki@blueleaf.cc)

An opaque type representing a string as an index into a table
of strings on the X server.
-}

#define ENABLE_OVERLOADING (MIN_VERSION_haskell_gi_overloading(1,0,0) \
       && !defined(__HADDOCK_VERSION__))

module GI.Gdk.Structs.Atom
    ( 

-- * Exported types
    Atom(..)                                ,
    noAtom                                  ,


 -- * Methods
-- ** intern #method:intern#

    atomIntern                              ,


-- ** internStaticString #method:internStaticString#

    atomInternStaticString                  ,


-- ** name #method:name#

#if ENABLE_OVERLOADING
    AtomNameMethodInfo                      ,
#endif
    atomName                                ,




    ) where

import Data.GI.Base.ShortPrelude
import qualified Data.GI.Base.ShortPrelude as SP
import qualified Data.GI.Base.Overloading as O
import qualified Prelude as P

import qualified Data.GI.Base.Attributes as GI.Attributes
import qualified Data.GI.Base.ManagedPtr as B.ManagedPtr
import qualified Data.GI.Base.GClosure as B.GClosure
import qualified Data.GI.Base.GError as B.GError
import qualified Data.GI.Base.GVariant as B.GVariant
import qualified Data.GI.Base.GValue as B.GValue
import qualified Data.GI.Base.GParamSpec as B.GParamSpec
import qualified Data.GI.Base.CallStack as B.CallStack
import qualified Data.GI.Base.Properties as B.Properties
import qualified Data.Text as T
import qualified Data.ByteString.Char8 as B
import qualified Data.Map as Map
import qualified Foreign.Ptr as FP
import qualified GHC.OverloadedLabels as OL


-- | Memory-managed wrapper type.
newtype Atom = Atom (ManagedPtr Atom)
-- XXX Wrapping a foreign struct/union with no known destructor or size, leak?
instance WrappedPtr Atom where
    wrappedPtrCalloc = return nullPtr
    wrappedPtrCopy = return
    wrappedPtrFree = Nothing

-- | A convenience alias for `Nothing` :: `Maybe` `Atom`.
noAtom :: Maybe Atom
noAtom = Nothing


#if ENABLE_OVERLOADING
instance O.HasAttributeList Atom
type instance O.AttributeList Atom = AtomAttributeList
type AtomAttributeList = ('[ ] :: [(Symbol, *)])
#endif

-- method Atom::name
-- method type : OrdinaryMethod
-- Args : [Arg {argCName = "atom", argType = TInterface (Name {namespace = "Gdk", name = "Atom"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a #GdkAtom.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TBasicType TUTF8)
-- throws : False
-- Skip return : False

foreign import ccall "gdk_atom_name" gdk_atom_name :: 
    Ptr Atom ->                             -- atom : TInterface (Name {namespace = "Gdk", name = "Atom"})
    IO CString

{- |
Determines the string corresponding to an atom.
-}
atomName ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    Atom
    {- ^ /@atom@/: a 'GI.Gdk.Structs.Atom.Atom'. -}
    -> m T.Text
    {- ^ __Returns:__ a newly-allocated string containing the string
  corresponding to /@atom@/. When you are done with the
  return value, you should free it using 'GI.GLib.Functions.free'. -}
atomName atom = liftIO $ do
    atom' <- unsafeManagedPtrGetPtr atom
    result <- gdk_atom_name atom'
    checkUnexpectedReturnNULL "atomName" result
    result' <- cstringToText result
    freeMem result
    touchManagedPtr atom
    return result'

#if ENABLE_OVERLOADING
data AtomNameMethodInfo
instance (signature ~ (m T.Text), MonadIO m) => O.MethodInfo AtomNameMethodInfo Atom signature where
    overloadedMethod _ = atomName

#endif

-- method Atom::intern
-- method type : MemberFunction
-- Args : [Arg {argCName = "atom_name", argType = TBasicType TUTF8, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a string.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing},Arg {argCName = "only_if_exists", argType = TBasicType TBoolean, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "if %TRUE, GDK is allowed to not create a new atom, but\n  just return %GDK_NONE if the requested atom doesn\8217t already\n  exists. Currently, the flag is ignored, since checking the\n  existance of an atom is as expensive as creating it.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TInterface (Name {namespace = "Gdk", name = "Atom"}))
-- throws : False
-- Skip return : False

foreign import ccall "gdk_atom_intern" gdk_atom_intern :: 
    CString ->                              -- atom_name : TBasicType TUTF8
    CInt ->                                 -- only_if_exists : TBasicType TBoolean
    IO (Ptr Atom)

{- |
Finds or creates an atom corresponding to a given string.
-}
atomIntern ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    T.Text
    {- ^ /@atomName@/: a string. -}
    -> Bool
    {- ^ /@onlyIfExists@/: if 'True', GDK is allowed to not create a new atom, but
  just return @/GDK_NONE/@ if the requested atom doesn’t already
  exists. Currently, the flag is ignored, since checking the
  existance of an atom is as expensive as creating it. -}
    -> m Atom
    {- ^ __Returns:__ the atom corresponding to /@atomName@/. -}
atomIntern atomName onlyIfExists = liftIO $ do
    atomName' <- textToCString atomName
    let onlyIfExists' = (fromIntegral . fromEnum) onlyIfExists
    result <- gdk_atom_intern atomName' onlyIfExists'
    checkUnexpectedReturnNULL "atomIntern" result
    result' <- (newPtr Atom) result
    freeMem atomName'
    return result'

#if ENABLE_OVERLOADING
#endif

-- method Atom::intern_static_string
-- method type : MemberFunction
-- Args : [Arg {argCName = "atom_name", argType = TBasicType TUTF8, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a static string", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TInterface (Name {namespace = "Gdk", name = "Atom"}))
-- throws : False
-- Skip return : False

foreign import ccall "gdk_atom_intern_static_string" gdk_atom_intern_static_string :: 
    CString ->                              -- atom_name : TBasicType TUTF8
    IO (Ptr Atom)

{- |
Finds or creates an atom corresponding to a given string.

Note that this function is identical to 'GI.Gdk.Functions.atomIntern' except
that if a new 'GI.Gdk.Structs.Atom.Atom' is created the string itself is used rather
than a copy. This saves memory, but can only be used if the string
will always exist. It can be used with statically
allocated strings in the main program, but not with statically
allocated memory in dynamically loaded modules, if you expect to
ever unload the module again (e.g. do not use this function in
GTK+ theme engines).

/Since: 2.10/
-}
atomInternStaticString ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    T.Text
    {- ^ /@atomName@/: a static string -}
    -> m Atom
    {- ^ __Returns:__ the atom corresponding to /@atomName@/ -}
atomInternStaticString atomName = liftIO $ do
    atomName' <- textToCString atomName
    result <- gdk_atom_intern_static_string atomName'
    checkUnexpectedReturnNULL "atomInternStaticString" result
    result' <- (newPtr Atom) result
    freeMem atomName'
    return result'

#if ENABLE_OVERLOADING
#endif

#if ENABLE_OVERLOADING
type family ResolveAtomMethod (t :: Symbol) (o :: *) :: * where
    ResolveAtomMethod "name" o = AtomNameMethodInfo
    ResolveAtomMethod l o = O.MethodResolutionFailed l o

instance (info ~ ResolveAtomMethod t Atom, O.MethodInfo info Atom p) => OL.IsLabel t (Atom -> p) where
#if MIN_VERSION_base(4,10,0)
    fromLabel = O.overloadedMethod (O.MethodProxy :: O.MethodProxy info)
#else
    fromLabel _ = O.overloadedMethod (O.MethodProxy :: O.MethodProxy info)
#endif

#endif