{- | Copyright : Will Thompson, Iñaki García Etxebarria and Jonas Platte License : LGPL-2.1 Maintainer : Iñaki García Etxebarria (garetxe@gmail.com) 'GI.Gst.Structs.Context.Context' is a container object used to store contexts like a device context, a display server connection and similar concepts that should be shared between multiple elements. Applications can set a context on a complete pipeline by using 'GI.Gst.Objects.Element.elementSetContext', which will then be propagated to all child elements. Elements can handle these in 'GI.Gst.Structs.ElementClass.ElementClass'.@/set_context/@() and merge them with the context information they already have. When an element needs a context it will do the following actions in this order until one step succeeds: 1. Check if the element already has a context 2. Query downstream with GST_QUERY_CONTEXT for the context 3. Query upstream with GST_QUERY_CONTEXT for the context 4. Post a GST_MESSAGE_NEED_CONTEXT message on the bus with the required context types and afterwards check if a usable context was set now 5. Create a context by itself and post a GST_MESSAGE_HAVE_CONTEXT message on the bus. Bins will catch GST_MESSAGE_NEED_CONTEXT messages and will set any previously known context on the element that asks for it if possible. Otherwise the application should provide one if it can. 'GI.Gst.Structs.Context.Context'\<!-- -->s can be persistent. A persistent 'GI.Gst.Structs.Context.Context' is kept in elements when they reach 'GI.Gst.Enums.StateNull', non-persistent ones will be removed. Also, a non-persistent context won\'t override a previous persistent context set to an element. -} module GI.Gst.Structs.Context ( -- * Exported types Context(..) , noContext , -- * Methods -- ** getContextType #method:getContextType# #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) ContextGetContextTypeMethodInfo , #endif contextGetContextType , -- ** getStructure #method:getStructure# #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) ContextGetStructureMethodInfo , #endif contextGetStructure , -- ** hasContextType #method:hasContextType# #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) ContextHasContextTypeMethodInfo , #endif contextHasContextType , -- ** isPersistent #method:isPersistent# #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) ContextIsPersistentMethodInfo , #endif contextIsPersistent , -- ** new #method:new# contextNew , -- ** writableStructure #method:writableStructure# #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) ContextWritableStructureMethodInfo , #endif contextWritableStructure , ) 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.GError as B.GError import qualified Data.GI.Base.GVariant as B.GVariant import qualified Data.GI.Base.GParamSpec as B.GParamSpec import qualified Data.GI.Base.CallStack as B.CallStack 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 {-# SOURCE #-} qualified GI.Gst.Structs.Structure as Gst.Structure newtype Context = Context (ManagedPtr Context) foreign import ccall "gst_context_get_type" c_gst_context_get_type :: IO GType instance BoxedObject Context where boxedType _ = c_gst_context_get_type noContext :: Maybe Context noContext = Nothing #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) instance O.HasAttributeList Context type instance O.AttributeList Context = ContextAttributeList type ContextAttributeList = ('[ ] :: [(Symbol, *)]) #endif -- method Context::new -- method type : Constructor -- Args : [Arg {argCName = "context_type", argType = TBasicType TUTF8, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "Context type", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing},Arg {argCName = "persistent", argType = TBasicType TBoolean, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "Persistent context", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}] -- Lengths : [] -- returnType : Just (TInterface (Name {namespace = "Gst", name = "Context"})) -- throws : False -- Skip return : False foreign import ccall "gst_context_new" gst_context_new :: CString -> -- context_type : TBasicType TUTF8 CInt -> -- persistent : TBasicType TBoolean IO (Ptr Context) {- | Create a new context. @since 1.2 -} contextNew :: (B.CallStack.HasCallStack, MonadIO m) => T.Text {- ^ /@contextType@/: Context type -} -> Bool {- ^ /@persistent@/: Persistent context -} -> m Context {- ^ __Returns:__ The new context. -} contextNew contextType persistent = liftIO $ do contextType' <- textToCString contextType let persistent' = (fromIntegral . fromEnum) persistent result <- gst_context_new contextType' persistent' checkUnexpectedReturnNULL "contextNew" result result' <- (wrapBoxed Context) result freeMem contextType' return result' #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) #endif -- method Context::get_context_type -- method type : OrdinaryMethod -- Args : [Arg {argCName = "context", argType = TInterface (Name {namespace = "Gst", name = "Context"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "The #GstContext.", 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 "gst_context_get_context_type" gst_context_get_context_type :: Ptr Context -> -- context : TInterface (Name {namespace = "Gst", name = "Context"}) IO CString {- | Get the type of /@context@/. @since 1.2 -} contextGetContextType :: (B.CallStack.HasCallStack, MonadIO m) => Context {- ^ /@context@/: The 'GI.Gst.Structs.Context.Context'. -} -> m T.Text {- ^ __Returns:__ The type of the context. -} contextGetContextType context = liftIO $ do context' <- unsafeManagedPtrGetPtr context result <- gst_context_get_context_type context' checkUnexpectedReturnNULL "contextGetContextType" result result' <- cstringToText result touchManagedPtr context return result' #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) data ContextGetContextTypeMethodInfo instance (signature ~ (m T.Text), MonadIO m) => O.MethodInfo ContextGetContextTypeMethodInfo Context signature where overloadedMethod _ = contextGetContextType #endif -- method Context::get_structure -- method type : OrdinaryMethod -- Args : [Arg {argCName = "context", argType = TInterface (Name {namespace = "Gst", name = "Context"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "The #GstContext.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}] -- Lengths : [] -- returnType : Just (TInterface (Name {namespace = "Gst", name = "Structure"})) -- throws : False -- Skip return : False foreign import ccall "gst_context_get_structure" gst_context_get_structure :: Ptr Context -> -- context : TInterface (Name {namespace = "Gst", name = "Context"}) IO (Ptr Gst.Structure.Structure) {- | Access the structure of the context. @since 1.2 -} contextGetStructure :: (B.CallStack.HasCallStack, MonadIO m) => Context {- ^ /@context@/: The 'GI.Gst.Structs.Context.Context'. -} -> m Gst.Structure.Structure {- ^ __Returns:__ The structure of the context. The structure is still owned by the context, which means that you should not modify it, free it and that the pointer becomes invalid when you free the context. -} contextGetStructure context = liftIO $ do context' <- unsafeManagedPtrGetPtr context result <- gst_context_get_structure context' checkUnexpectedReturnNULL "contextGetStructure" result result' <- (newBoxed Gst.Structure.Structure) result touchManagedPtr context return result' #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) data ContextGetStructureMethodInfo instance (signature ~ (m Gst.Structure.Structure), MonadIO m) => O.MethodInfo ContextGetStructureMethodInfo Context signature where overloadedMethod _ = contextGetStructure #endif -- method Context::has_context_type -- method type : OrdinaryMethod -- Args : [Arg {argCName = "context", argType = TInterface (Name {namespace = "Gst", name = "Context"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "The #GstContext.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing},Arg {argCName = "context_type", argType = TBasicType TUTF8, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "Context type to check.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}] -- Lengths : [] -- returnType : Just (TBasicType TBoolean) -- throws : False -- Skip return : False foreign import ccall "gst_context_has_context_type" gst_context_has_context_type :: Ptr Context -> -- context : TInterface (Name {namespace = "Gst", name = "Context"}) CString -> -- context_type : TBasicType TUTF8 IO CInt {- | Checks if /@context@/ has /@contextType@/. @since 1.2 -} contextHasContextType :: (B.CallStack.HasCallStack, MonadIO m) => Context {- ^ /@context@/: The 'GI.Gst.Structs.Context.Context'. -} -> T.Text {- ^ /@contextType@/: Context type to check. -} -> m Bool {- ^ __Returns:__ 'True' if /@context@/ has /@contextType@/. -} contextHasContextType context contextType = liftIO $ do context' <- unsafeManagedPtrGetPtr context contextType' <- textToCString contextType result <- gst_context_has_context_type context' contextType' let result' = (/= 0) result touchManagedPtr context freeMem contextType' return result' #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) data ContextHasContextTypeMethodInfo instance (signature ~ (T.Text -> m Bool), MonadIO m) => O.MethodInfo ContextHasContextTypeMethodInfo Context signature where overloadedMethod _ = contextHasContextType #endif -- method Context::is_persistent -- method type : OrdinaryMethod -- Args : [Arg {argCName = "context", argType = TInterface (Name {namespace = "Gst", name = "Context"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "The #GstContext.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}] -- Lengths : [] -- returnType : Just (TBasicType TBoolean) -- throws : False -- Skip return : False foreign import ccall "gst_context_is_persistent" gst_context_is_persistent :: Ptr Context -> -- context : TInterface (Name {namespace = "Gst", name = "Context"}) IO CInt {- | Check if /@context@/ is persistent. @since 1.2 -} contextIsPersistent :: (B.CallStack.HasCallStack, MonadIO m) => Context {- ^ /@context@/: The 'GI.Gst.Structs.Context.Context'. -} -> m Bool {- ^ __Returns:__ 'True' if the context is persistent. -} contextIsPersistent context = liftIO $ do context' <- unsafeManagedPtrGetPtr context result <- gst_context_is_persistent context' let result' = (/= 0) result touchManagedPtr context return result' #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) data ContextIsPersistentMethodInfo instance (signature ~ (m Bool), MonadIO m) => O.MethodInfo ContextIsPersistentMethodInfo Context signature where overloadedMethod _ = contextIsPersistent #endif -- method Context::writable_structure -- method type : OrdinaryMethod -- Args : [Arg {argCName = "context", argType = TInterface (Name {namespace = "Gst", name = "Context"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "The #GstContext.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}] -- Lengths : [] -- returnType : Just (TInterface (Name {namespace = "Gst", name = "Structure"})) -- throws : False -- Skip return : False foreign import ccall "gst_context_writable_structure" gst_context_writable_structure :: Ptr Context -> -- context : TInterface (Name {namespace = "Gst", name = "Context"}) IO (Ptr Gst.Structure.Structure) {- | Get a writable version of the structure. @since 1.2 -} contextWritableStructure :: (B.CallStack.HasCallStack, MonadIO m) => Context {- ^ /@context@/: The 'GI.Gst.Structs.Context.Context'. -} -> m Gst.Structure.Structure {- ^ __Returns:__ The structure of the context. The structure is still owned by the context, which means that you should not free it and that the pointer becomes invalid when you free the context. This function checks if /@context@/ is writable. -} contextWritableStructure context = liftIO $ do context' <- unsafeManagedPtrGetPtr context result <- gst_context_writable_structure context' checkUnexpectedReturnNULL "contextWritableStructure" result result' <- (wrapBoxed Gst.Structure.Structure) result touchManagedPtr context return result' #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) data ContextWritableStructureMethodInfo instance (signature ~ (m Gst.Structure.Structure), MonadIO m) => O.MethodInfo ContextWritableStructureMethodInfo Context signature where overloadedMethod _ = contextWritableStructure #endif #if defined(ENABLE_OVERLOADING) && !defined(__HADDOCK_VERSION__) type family ResolveContextMethod (t :: Symbol) (o :: *) :: * where ResolveContextMethod "hasContextType" o = ContextHasContextTypeMethodInfo ResolveContextMethod "isPersistent" o = ContextIsPersistentMethodInfo ResolveContextMethod "writableStructure" o = ContextWritableStructureMethodInfo ResolveContextMethod "getContextType" o = ContextGetContextTypeMethodInfo ResolveContextMethod "getStructure" o = ContextGetStructureMethodInfo ResolveContextMethod l o = O.MethodResolutionFailed l o instance (info ~ ResolveContextMethod t Context, O.MethodInfo info Context p) => O.IsLabelProxy t (Context -> p) where fromLabelProxy _ = O.overloadedMethod (O.MethodProxy :: O.MethodProxy info) #if MIN_VERSION_base(4,9,0) instance (info ~ ResolveContextMethod t Context, O.MethodInfo info Context p) => O.IsLabel t (Context -> 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 #endif