    {-# LANGUAGE TypeApplications #-}

    -- | Copyright  : Will Thompson and Iñaki García Etxebarria
    -- License    : LGPL-2.1
    -- Maintainer : Iñaki García Etxebarria
    --
    -- Provides a way to describe references to values.
    --
    -- An important aspect of expressions is that the value can be obtained
    -- from a source that is several steps away. For example, an expression
    -- may describe ‘the value of property A of @object1@, which is itself the
    -- value of a property of @object2@’. And @object1@ may not even exist yet
    -- at the time that the expression is created. This is contrast to @GObject@
    -- property bindings, which can only create direct connections between
    -- the properties of two objects that must both exist for the duration
    -- of the binding.
    --
    -- An expression needs to be \"evaluated\" to obtain the value that it currently
    -- refers to. An evaluation always happens in the context of a current object
    -- called @this@ (it mirrors the behavior of object-oriented languages),
    -- which may or may not influence the result of the evaluation. Use
    -- 'GI.Gtk.Objects.Expression.expressionEvaluate' for evaluating an expression.
    --
    -- Various methods for defining expressions exist, from simple constants via
    -- t'GI.Gtk.Objects.ConstantExpression.ConstantExpression'.@/new/@() to looking up properties in a @GObject@
    -- (even recursively) via 'GI.Gtk.Objects.PropertyExpression.propertyExpressionNew' or providing
    -- custom functions to transform and combine expressions via
    -- 'GI.Gtk.Objects.ClosureExpression.closureExpressionNew'.
    --
    -- Here is an example of a complex expression:
    --
    --
    -- === /c code/
    -- >  color_expr = gtk_property_expression_new (GTK_TYPE_LIST_ITEM,
    -- >                                            NULL, "item");
    -- >  expression = gtk_property_expression_new (GTK_TYPE_COLOR,
    -- >                                            color_expr, "name");
    --
    --
    -- when evaluated with @this@ being a @GtkListItem@, it will obtain the
    -- \"item\" property from the @GtkListItem@, and then obtain the \"name\" property
    -- from the resulting object (which is assumed to be of type @GTK_TYPE_COLOR@).
    --
    -- A more concise way to describe this would be
    --
    --
    --
    -- >  this->item->name
    --
    --
    -- The most likely place where you will encounter expressions is in the context
    -- of list models and list widgets using them. For example, @GtkDropDown@ is
    -- evaluating a @GtkExpression@ to obtain strings from the items in its model
    -- that it can then use to match against the contents of its search entry.
    -- @GtkStringFilter@ is using a @GtkExpression@ for similar reasons.
    --
    -- By default, expressions are not paying attention to changes and evaluation is
    -- just a snapshot of the current state at a given time. To get informed about
    -- changes, an expression needs to be \"watched\" via a t'GI.Gtk.Structs.ExpressionWatch.ExpressionWatch',
    -- which will cause a callback to be called whenever the value of the expression may
    -- have changed; 'GI.Gtk.Objects.Expression.expressionWatch' starts watching an expression, and
    -- 'GI.Gtk.Structs.ExpressionWatch.expressionWatchUnwatch' stops.
    --
    -- Watches can be created for automatically updating the property of an object,
    -- similar to GObject\'s @GBinding@ mechanism, by using 'GI.Gtk.Objects.Expression.expressionBind'.
    --
    -- == GtkExpression in GObject properties
    --
    -- In order to use a @GtkExpression@ as a @GObject@ property, you must use the
    -- 'GI.Gtk.Functions.paramSpecExpression' when creating a @GParamSpec@ to install in the
    -- @GObject@ class being defined; for instance:
    --
    --
    -- === /c code/
    -- >obj_props[PROP_EXPRESSION] =
    -- >  gtk_param_spec_expression ("expression",
    -- >                             "Expression",
    -- >                             "The expression used by the widget",
    -- >                             G_PARAM_READWRITE |
    -- >                             G_PARAM_STATIC_STRINGS |
    -- >                             G_PARAM_EXPLICIT_NOTIFY);
    --
    --
    -- When implementing the @GObjectClass.set_property@ and @GObjectClass.get_property@
    -- virtual functions, you must use 'GI.Gtk.Functions.valueGetExpression', to retrieve the
    -- stored @GtkExpression@ from the @GValue@ container, and 'GI.Gtk.Functions.valueSetExpression',
    -- to store the @GtkExpression@ into the @GValue@; for instance:
    --
    --
    -- === /c code/
    -- >  // in set_property()...
    -- >  case PROP_EXPRESSION:
    -- >    foo_widget_set_expression (foo, gtk_value_get_expression (value));
    -- >    break;
    -- >
    -- >  // in get_property()...
    -- >  case PROP_EXPRESSION:
    -- >    gtk_value_set_expression (value, foo->expression);
    -- >    break;
    --
    --
    -- == GtkExpression in .ui files
    --
    -- @GtkBuilder@ has support for creating expressions. The syntax here can be used where
    -- a @GtkExpression@ object is needed like in a @\<property>@ tag for an expression
    -- property, or in a @\<binding name=\"property\">@ tag to bind a property to an expression.
    --
    -- To create a property expression, use the @\<lookup>@ element. It can have a @type@
    -- attribute to specify the object type, and a @name@ attribute to specify the property
    -- to look up. The content of @\<lookup>@ can either be a string that specifies the name
    -- of the object to use, an element specifying an expression to provide an object, or
    -- empty to use the @this@ object.
    --
    -- Example:
    --
    --
    -- === /xml code/
    -- >  <lookup name='search'>string_filter</lookup>
    --
    --
    -- Since the @\<lookup>@ element creates an expression and its element content can
    -- itself be an expression, this means that @\<lookup>@ tags can also be nested.
    -- This is a common idiom when dealing with @GtkListItem@s. See
    -- t'GI.Gtk.Objects.BuilderListItemFactory.BuilderListItemFactory' for an example of this technique.
    --
    -- To create a constant expression, use the @\<constant>@ element. If the type attribute
    -- is specified, the element content is interpreted as a value of that type, and the
    -- initial attribute can be specified to get the initial value for that type. Otherwise,
    -- it is assumed to be an object. For instance:
    --
    --
    -- === /xml code/
    -- >  <constant>string_filter</constant>
    -- >  <constant type='gchararray'>Hello, world</constant>
    -- >  <constant type='gchararray' initial='true' /> <!-- NULL -->
    --
    --
    -- String (@type=\'gchararray\'@) constants can be marked for translation with the
    -- @translatable=@ attribute, and will then be looked up in the
    -- [Builder:translationDomain]("GI.Gtk.Objects.Builder#g:attr:translationDomain") when the expression is constructed.
    --
    --
    -- === /xml code/
    -- >  <constant type='gchararray' translatable='yes'>I'm translatable!</constant>
    --
    --
    -- As with other translatable strings in [type/@gtk@/.Builder], constants can
    -- also have a context and\/or translation comment:
    --
    --
    -- === /xml code/
    -- >  <constant type='gchararray'
    -- >            translatable='yes'
    -- >            context='example'
    -- >            comments='A sample string'>I'm translatable!</constant>
    --
    --
    -- To create a closure expression, use the @\<closure>@ element. The @function@
    -- attribute specifies what function to use for the closure, and the @type@
    -- attribute specifies its return type. The content of the element contains the
    -- expressions for the parameters. For instance:
    --
    --
    -- === /xml code/
    -- >  <closure type='gchararray' function='combine_args_somehow'>
    -- >    <constant type='gchararray'>File size:</constant>
    -- >    <lookup type='GFile' name='size'>myfile</lookup>
    -- >  </closure>
    --
    --
    -- If an expression can fail, a @\<try>@ element can be used to provide fallbacks.
    -- The expressions are tried from top to bottom until one of them succeeds.
    -- If none of the expressions succeed, the expression fails as normal:
    --
    --
    -- === /xml code/
    -- >  <try>
    -- >    <lookup type='GtkWindow' name='title'>
    -- >      <lookup type='GtkLabel' name='root'></lookup>
    -- >    </lookup>
    -- >    <constant type='gchararray'>Hello World</constant>
    -- >  </try>
    --
    --
    -- To create a property binding, use the @\<binding>@ element in place of where a
    -- @\<property>@ tag would ordinarily be used. The @name@ and @object@ attributes are
    -- supported. The @name@ attribute is required, and pertains to the applicable property
    -- name. The @object@ attribute is optional. If provided, it will use the specified object
    -- as the @this@ object when the expression is evaluated. Here is an example in which the
    -- @label@ property of a @GtkLabel@ is bound to the @string@ property of another arbitrary
    -- object:
    --
    --
    -- === /xml code/
    -- >  <object class='GtkLabel'>
    -- >    <binding name='label'>
    -- >      <lookup name='string'>some_other_object</lookup>
    -- >    </binding>
    -- >  </object>
    --

    #if !defined(__HADDOCK_VERSION__)
    #define ENABLE_OVERLOADING
    #endif

    module GI.Gtk.Objects.Expression
        (

    -- * Exported types
        Expression(..)                          ,
        IsExpression                            ,
        toExpression                            ,

     -- * Methods
    -- |
    --
    --  === __Click to display all available methods, including inherited ones__
    -- ==== Methods
    -- [bind]("GI.Gtk.Objects.Expression#g:method:bind"), [evaluate]("GI.Gtk.Objects.Expression#g:method:evaluate"), [isStatic]("GI.Gtk.Objects.Expression#g:method:isStatic"), [ref]("GI.Gtk.Objects.Expression#g:method:ref"), [unref]("GI.Gtk.Objects.Expression#g:method:unref"), [watch]("GI.Gtk.Objects.Expression#g:method:watch").
    --
    -- ==== Getters
    -- [getValueType]("GI.Gtk.Objects.Expression#g:method:getValueType").
    --
    -- ==== Setters
    -- /None/.

    #if defined(ENABLE_OVERLOADING)
        ResolveExpressionMethod                 ,
    #endif

    -- ** bind #method:bind#

    #if defined(ENABLE_OVERLOADING)
        ExpressionBindMethodInfo                ,
    #endif
        expressionBind                          ,

    -- ** evaluate #method:evaluate#

    #if defined(ENABLE_OVERLOADING)
        ExpressionEvaluateMethodInfo            ,
    #endif
        expressionEvaluate                      ,

    -- ** getValueType #method:getValueType#

    #if defined(ENABLE_OVERLOADING)
        ExpressionGetValueTypeMethodInfo        ,
    #endif
        expressionGetValueType                  ,

    -- ** isStatic #method:isStatic#

    #if defined(ENABLE_OVERLOADING)
        ExpressionIsStaticMethodInfo            ,
    #endif
        expressionIsStatic                      ,

    -- ** ref #method:ref#

    #if defined(ENABLE_OVERLOADING)
        ExpressionRefMethodInfo                 ,
    #endif
        expressionRef                           ,

    -- ** unref #method:unref#

    #if defined(ENABLE_OVERLOADING)
        ExpressionUnrefMethodInfo               ,
    #endif
        expressionUnref                         ,

    -- ** watch #method:watch#

    #if defined(ENABLE_OVERLOADING)
        ExpressionWatchMethodInfo               ,
    #endif
        expressionWatch                         ,

        ) 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.BasicTypes as B.Types
    import qualified Data.GI.Base.ManagedPtr as B.ManagedPtr
    import qualified Data.GI.Base.GArray as B.GArray
    import qualified Data.GI.Base.GClosure as B.GClosure
    import qualified Data.GI.Base.GError as B.GError
    import qualified Data.GI.Base.GHashTable as B.GHT
    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.GI.Base.Signals as B.Signals
    import qualified Control.Monad.IO.Class as MIO
    import qualified Data.Coerce as Coerce
    import qualified Data.Text as T
    import qualified Data.Kind as DK
    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
    import qualified GHC.Records as R
    import qualified Data.Word as DW
    import qualified Data.Int as DI
    import qualified System.Posix.Types as SPT
    import qualified Foreign.C.Types as FCT

    -- Workaround for https://gitlab.haskell.org/ghc/ghc/-/issues/23392
    #if MIN_VERSION_base(4,18,0)
    import qualified GI.GLib.Callbacks as GLib.Callbacks
    import qualified GI.GObject.Objects.Object as GObject.Object
    import qualified GI.Gtk.Callbacks as Gtk.Callbacks
    import {-# SOURCE #-} qualified GI.Gtk.Structs.ExpressionWatch as Gtk.ExpressionWatch

    #else
    import qualified GI.GLib.Callbacks as GLib.Callbacks
    import qualified GI.GObject.Objects.Object as GObject.Object
    import qualified GI.Gtk.Callbacks as Gtk.Callbacks
    import {-# SOURCE #-} qualified GI.Gtk.Structs.ExpressionWatch as Gtk.ExpressionWatch

    #endif

    -- | Memory-managed wrapper type.
    newtype Expression = Expression (SP.ManagedPtr Expression)
        deriving (Expression -> Expression -> Bool
    (Expression -> Expression -> Bool)
    -> (Expression -> Expression -> Bool) -> Eq Expression
    forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
    $c== :: Expression -> Expression -> Bool
    == :: Expression -> Expression -> Bool
    $c/= :: Expression -> Expression -> Bool
    /= :: Expression -> Expression -> Bool
    Eq)

    instance SP.ManagedPtrNewtype Expression where
        toManagedPtr :: Expression -> ManagedPtr Expression
    toManagedPtr (Expression ManagedPtr Expression
    p) = ManagedPtr Expression
    p

    foreign import ccall "gtk_expression_get_type"
        c_gtk_expression_get_type :: IO B.Types.GType

    instance B.Types.TypedObject Expression where
        glibType :: IO GType
    glibType = IO GType
    c_gtk_expression_get_type

    -- | Type class for types which can be safely cast to t'Expression', for instance with `toExpression`.
    class (SP.BoxedPtr o, SP.TypedObject o, O.IsDescendantOf Expression o) => IsExpression o
    instance (SP.BoxedPtr o, SP.TypedObject o, O.IsDescendantOf Expression o) => IsExpression o

    instance O.HasParentTypes Expression
    type instance O.ParentTypes Expression = '[]

    -- | Cast to t'Expression', for types for which this is known to be safe. For general casts, use 'Data.GI.Base.ManagedPtr.castTo'.
    toExpression :: (MIO.MonadIO m, IsExpression o) => o -> m Expression
    toExpression :: forall (m :: * -> *) o.
    (MonadIO m, IsExpression o) =>
    o -> m Expression
    toExpression = IO Expression -> m Expression
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    MIO.liftIO (IO Expression -> m Expression)
    -> (o -> IO Expression) -> o -> m Expression
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . (ManagedPtr Expression -> Expression) -> o -> IO Expression
    forall o o'.
    (HasCallStack, ManagedPtrNewtype o, TypedObject o,
     ManagedPtrNewtype o', TypedObject o') =>
    (ManagedPtr o' -> o') -> o -> IO o'
    B.ManagedPtr.unsafeCastTo ManagedPtr Expression -> Expression
    Expression

    foreign import ccall "gtk_value_get_expression" gv_get_gtk_value_get_expression ::
        FP.Ptr B.GValue.GValue -> IO (FP.Ptr Expression)

    foreign import ccall "gtk_value_set_expression" gv_set_gtk_value_set_expression ::
        FP.Ptr B.GValue.GValue -> FP.Ptr Expression -> IO ()

    -- | Convert t'Expression' to and from t'Data.GI.Base.GValue.GValue'. See 'Data.GI.Base.GValue.toGValue' and 'Data.GI.Base.GValue.fromGValue'.
    instance B.GValue.IsGValue (Maybe Expression) where
        gvalueGType_ :: IO GType
    gvalueGType_ = IO GType
    c_gtk_expression_get_type
        gvalueSet_ :: Ptr GValue -> Maybe Expression -> IO ()
    gvalueSet_ Ptr GValue
    gv Maybe Expression
    P.Nothing = Ptr GValue -> Ptr Expression -> IO ()
    gv_set_gtk_value_set_expression Ptr GValue
    gv (Ptr Expression
    forall a. Ptr a
    FP.nullPtr :: FP.Ptr Expression)
        gvalueSet_ Ptr GValue
    gv (P.Just Expression
    obj) = Expression -> (Ptr Expression -> IO ()) -> IO ()
    forall a c.
    (HasCallStack, ManagedPtrNewtype a) =>
    a -> (Ptr a -> IO c) -> IO c
    B.ManagedPtr.withManagedPtr Expression
    obj (Ptr GValue -> Ptr Expression -> IO ()
    gv_set_gtk_value_set_expression Ptr GValue
    gv)
        gvalueGet_ :: Ptr GValue -> IO (Maybe Expression)
    gvalueGet_ Ptr GValue
    gv = do
            ptr <- Ptr GValue -> IO (Ptr Expression)
    gv_get_gtk_value_get_expression Ptr GValue
    gv :: IO (FP.Ptr Expression)
            if ptr /= FP.nullPtr
            then P.Just <$> B.ManagedPtr.newPtr Expression ptr
            else return P.Nothing

    #if defined(ENABLE_OVERLOADING)
    type family ResolveExpressionMethod (t :: Symbol) (o :: DK.Type) :: DK.Type where
        ResolveExpressionMethod "bind" o = ExpressionBindMethodInfo
        ResolveExpressionMethod "evaluate" o = ExpressionEvaluateMethodInfo
        ResolveExpressionMethod "isStatic" o = ExpressionIsStaticMethodInfo
        ResolveExpressionMethod "ref" o = ExpressionRefMethodInfo
        ResolveExpressionMethod "unref" o = ExpressionUnrefMethodInfo
        ResolveExpressionMethod "watch" o = ExpressionWatchMethodInfo
        ResolveExpressionMethod "getValueType" o = ExpressionGetValueTypeMethodInfo
        ResolveExpressionMethod l o = O.MethodResolutionFailed l o

    instance (info ~ ResolveExpressionMethod t Expression, O.OverloadedMethod info Expression p) => OL.IsLabel t (Expression -> p) where
    #if MIN_VERSION_base(4,10,0)
        fromLabel = O.overloadedMethod @info
    #else
        fromLabel _ = O.overloadedMethod @info
    #endif

    #if MIN_VERSION_base(4,13,0)
    instance (info ~ ResolveExpressionMethod t Expression, O.OverloadedMethod info Expression p, R.HasField t Expression p) => R.HasField t Expression p where
        getField = O.overloadedMethod @info

    #endif

    instance (info ~ ResolveExpressionMethod t Expression, O.OverloadedMethodInfo info Expression) => OL.IsLabel t (O.MethodProxy info Expression) where
    #if MIN_VERSION_base(4,10,0)
        fromLabel = O.MethodProxy
    #else
        fromLabel _ = O.MethodProxy
    #endif

    #endif

    foreign import ccall "gtk_expression_ref" _Expression_copy_gtk_expression_ref :: Ptr a -> IO (Ptr a)

    foreign import ccall "gtk_expression_unref" _Expression_free_gtk_expression_unref :: Ptr a -> IO ()

    instance BoxedPtr Expression where
        boxedPtrCopy :: Expression -> IO Expression
    boxedPtrCopy = \Expression
    p -> Expression -> (Ptr Expression -> IO Expression) -> IO Expression
    forall a c.
    (HasCallStack, ManagedPtrNewtype a) =>
    a -> (Ptr a -> IO c) -> IO c
    B.ManagedPtr.withManagedPtr Expression
    p (Ptr Expression -> IO (Ptr Expression)
    forall a. Ptr a -> IO (Ptr a)
    _Expression_copy_gtk_expression_ref (Ptr Expression -> IO (Ptr Expression))
    -> (Ptr Expression -> IO Expression)
    -> Ptr Expression
    -> IO Expression
    forall (m :: * -> *) a b c.
    Monad m =>
    (a -> m b) -> (b -> m c) -> a -> m c
    >=> (ManagedPtr Expression -> Expression)
    -> Ptr Expression -> IO Expression
    forall a.
    (HasCallStack, BoxedPtr a) =>
    (ManagedPtr a -> a) -> Ptr a -> IO a
    B.ManagedPtr.wrapPtr ManagedPtr Expression -> Expression
    Expression)
        boxedPtrFree :: Expression -> IO ()
    boxedPtrFree = \Expression
    p -> Expression -> (Ptr Expression -> IO ()) -> IO ()
    forall a c.
    (HasCallStack, ManagedPtrNewtype a) =>
    a -> (Ptr a -> IO c) -> IO c
    B.ManagedPtr.withManagedPtr Expression
    p Ptr Expression -> IO ()
    forall a. Ptr a -> IO ()
    _Expression_free_gtk_expression_unref

    -- method Expression::bind
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferEverything
    --           }
    --       , Arg
    --           { argCName = "target"
    --           , argType =
    --               TInterface Name { namespace = "GObject" , name = "Object" }
    --           , argCType = Just "gpointer"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "the target object to bind to"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "property"
    --           , argType = TBasicType TUTF8
    --           , argCType = Just "const char*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "name of the property on `target` to bind to"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "this_"
    --           , argType =
    --               TInterface Name { namespace = "GObject" , name = "Object" }
    --           , argCType = Just "gpointer"
    --           , direction = DirectionIn
    --           , mayBeNull = True
    --           , argDoc =
    --               Documentation
    --                 { rawDocText =
    --                     Just "the this argument for\n  the evaluation of `self`"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just
    --               (TInterface Name { namespace = "Gtk" , name = "ExpressionWatch" })
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_bind" gtk_expression_bind ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        Ptr GObject.Object.Object ->            -- target : TInterface (Name {namespace = "GObject", name = "Object"})
        CString ->                              -- property : TBasicType TUTF8
        Ptr GObject.Object.Object ->            -- this_ : TInterface (Name {namespace = "GObject", name = "Object"})
        IO (Ptr Gtk.ExpressionWatch.ExpressionWatch)

    -- | Bind @target@\'s property named @property@ to @self@.
    --
    -- The value that @self@ evaluates to is set via @g_object_set()@ on
    -- @target@. This is repeated whenever @self@ changes to ensure that
    -- the object\'s property stays synchronized with @self@.
    --
    -- If @self@\'s evaluation fails, @target@\'s @property@ is not updated.
    -- Use a t'GI.Gtk.Objects.TryExpression.TryExpression' to provide a fallback for this case.
    --
    -- Note that this function takes ownership of @self@. If you want
    -- to keep it around, you should 'GI.Gtk.Objects.Expression.expressionRef' it beforehand.
    expressionBind ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a, GObject.Object.IsObject b, GObject.Object.IsObject c) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> b
        -- ^ /@target@/: the target object to bind to
        -> T.Text
        -- ^ /@property@/: name of the property on @target@ to bind to
        -> Maybe (c)
        -- ^ /@this_@/: the this argument for
        --   the evaluation of @self@
        -> m Gtk.ExpressionWatch.ExpressionWatch
        -- ^ __Returns:__ a @GtkExpressionWatch@
    expressionBind :: forall (m :: * -> *) a b c.
    (HasCallStack, MonadIO m, IsExpression a, IsObject b,
     IsObject c) =>
    a -> b -> Text -> Maybe c -> m ExpressionWatch
    expressionBind a
    self b
    target Text
    property Maybe c
    this_ = IO ExpressionWatch -> m ExpressionWatch
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO ExpressionWatch -> m ExpressionWatch)
    -> IO ExpressionWatch -> m ExpressionWatch
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    B.ManagedPtr.disownManagedPtr a
    self
        target' <- unsafeManagedPtrCastPtr target
        property' <- textToCString property
        maybeThis_ <- case this_ of
            Maybe c
    Nothing -> Ptr Object -> IO (Ptr Object)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Ptr Object
    forall a. Ptr a
    FP.nullPtr
            Just c
    jThis_ -> do
                jThis_' <- c -> IO (Ptr Object)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr c
    jThis_
                return jThis_'
        result <- gtk_expression_bind self' target' property' maybeThis_
        checkUnexpectedReturnNULL "expressionBind" result
        result' <- (newBoxed Gtk.ExpressionWatch.ExpressionWatch) result
        touchManagedPtr self
        touchManagedPtr target
        whenJust this_ touchManagedPtr
        freeMem property'
        return result'

    #if defined(ENABLE_OVERLOADING)
    data ExpressionBindMethodInfo
    instance (signature ~ (b -> T.Text -> Maybe (c) -> m Gtk.ExpressionWatch.ExpressionWatch), MonadIO m, IsExpression a, GObject.Object.IsObject b, GObject.Object.IsObject c) => O.OverloadedMethod ExpressionBindMethodInfo a signature where
        overloadedMethod = expressionBind

    instance O.OverloadedMethodInfo ExpressionBindMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionBind",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionBind"
            })

    #endif

    -- method Expression::evaluate
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "this_"
    --           , argType =
    --               TInterface Name { namespace = "GObject" , name = "Object" }
    --           , argCType = Just "gpointer"
    --           , direction = DirectionIn
    --           , mayBeNull = True
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "the this argument for the evaluation"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "value"
    --           , argType = TGValue
    --           , argCType = Just "GValue*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "an empty `GValue`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just (TBasicType TBoolean)
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_evaluate" gtk_expression_evaluate ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        Ptr GObject.Object.Object ->            -- this_ : TInterface (Name {namespace = "GObject", name = "Object"})
        Ptr GValue ->                           -- value : TGValue
        IO CInt

    -- | Evaluates the given expression and on success stores the result
    -- in /@value@/.
    --
    -- The @GType@ of @value@ will be the type given by
    -- 'GI.Gtk.Objects.Expression.expressionGetValueType'.
    --
    -- It is possible that expressions cannot be evaluated - for example
    -- when the expression references objects that have been destroyed or
    -- set to @NULL@. In that case @value@ will remain empty and @FALSE@
    -- will be returned.
    expressionEvaluate ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a, GObject.Object.IsObject b) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> Maybe (b)
        -- ^ /@this_@/: the this argument for the evaluation
        -> GValue
        -- ^ /@value@/: an empty @GValue@
        -> m Bool
        -- ^ __Returns:__ @TRUE@ if the expression could be evaluated
    expressionEvaluate :: forall (m :: * -> *) a b.
    (HasCallStack, MonadIO m, IsExpression a, IsObject b) =>
    a -> Maybe b -> GValue -> m Bool
    expressionEvaluate a
    self Maybe b
    this_ GValue
    value = IO Bool -> m Bool
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO Bool -> m Bool) -> IO Bool -> m Bool
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr a
    self
        maybeThis_ <- case this_ of
            Maybe b
    Nothing -> Ptr Object -> IO (Ptr Object)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Ptr Object
    forall a. Ptr a
    FP.nullPtr
            Just b
    jThis_ -> do
                jThis_' <- b -> IO (Ptr Object)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr b
    jThis_
                return jThis_'
        value' <- unsafeManagedPtrGetPtr value
        result <- gtk_expression_evaluate self' maybeThis_ value'
        let result' = (CInt -> CInt -> Bool
    forall a. Eq a => a -> a -> Bool
    /= CInt
    0) CInt
    result
        touchManagedPtr self
        whenJust this_ touchManagedPtr
        touchManagedPtr value
        return result'

    #if defined(ENABLE_OVERLOADING)
    data ExpressionEvaluateMethodInfo
    instance (signature ~ (Maybe (b) -> GValue -> m Bool), MonadIO m, IsExpression a, GObject.Object.IsObject b) => O.OverloadedMethod ExpressionEvaluateMethodInfo a signature where
        overloadedMethod = expressionEvaluate

    instance O.OverloadedMethodInfo ExpressionEvaluateMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionEvaluate",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionEvaluate"
            })

    #endif

    -- method Expression::get_value_type
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just (TBasicType TGType)
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_get_value_type" gtk_expression_get_value_type ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        IO CGType

    -- | Gets the @GType@ that this expression evaluates to.
    --
    -- This type is constant and will not change over the lifetime
    -- of this expression.
    expressionGetValueType ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> m GType
        -- ^ __Returns:__ The type returned from 'GI.Gtk.Objects.Expression.expressionEvaluate'
    expressionGetValueType :: forall (m :: * -> *) a.
    (HasCallStack, MonadIO m, IsExpression a) =>
    a -> m GType
    expressionGetValueType a
    self = IO GType -> m GType
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO GType -> m GType) -> IO GType -> m GType
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr a
    self
        result <- gtk_expression_get_value_type self'
        let result' = CGType -> GType
    GType CGType
    result
        touchManagedPtr self
        return result'

    #if defined(ENABLE_OVERLOADING)
    data ExpressionGetValueTypeMethodInfo
    instance (signature ~ (m GType), MonadIO m, IsExpression a) => O.OverloadedMethod ExpressionGetValueTypeMethodInfo a signature where
        overloadedMethod = expressionGetValueType

    instance O.OverloadedMethodInfo ExpressionGetValueTypeMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionGetValueType",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionGetValueType"
            })

    #endif

    -- method Expression::is_static
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just (TBasicType TBoolean)
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_is_static" gtk_expression_is_static ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        IO CInt

    -- | Checks if the expression is static.
    --
    -- A static expression will never change its result when
    -- 'GI.Gtk.Objects.Expression.expressionEvaluate' is called on it with the same arguments.
    --
    -- That means a call to 'GI.Gtk.Objects.Expression.expressionWatch' is not necessary because
    -- it will never trigger a notify.
    expressionIsStatic ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> m Bool
        -- ^ __Returns:__ @TRUE@ if the expression is static
    expressionIsStatic :: forall (m :: * -> *) a.
    (HasCallStack, MonadIO m, IsExpression a) =>
    a -> m Bool
    expressionIsStatic a
    self = IO Bool -> m Bool
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO Bool -> m Bool) -> IO Bool -> m Bool
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr a
    self
        result <- gtk_expression_is_static self'
        let result' = (CInt -> CInt -> Bool
    forall a. Eq a => a -> a -> Bool
    /= CInt
    0) CInt
    result
        touchManagedPtr self
        return result'

    #if defined(ENABLE_OVERLOADING)
    data ExpressionIsStaticMethodInfo
    instance (signature ~ (m Bool), MonadIO m, IsExpression a) => O.OverloadedMethod ExpressionIsStaticMethodInfo a signature where
        overloadedMethod = expressionIsStatic

    instance O.OverloadedMethodInfo ExpressionIsStaticMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionIsStatic",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionIsStatic"
            })

    #endif

    -- method Expression::ref
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just (TInterface Name { namespace = "Gtk" , name = "Expression" })
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_ref" gtk_expression_ref ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        IO (Ptr Expression)

    -- | Acquires a reference on the given @GtkExpression@.
    expressionRef ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> m Expression
        -- ^ __Returns:__ the @GtkExpression@ with an additional reference
    expressionRef :: forall (m :: * -> *) a.
    (HasCallStack, MonadIO m, IsExpression a) =>
    a -> m Expression
    expressionRef a
    self = IO Expression -> m Expression
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO Expression -> m Expression) -> IO Expression -> m Expression
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr a
    self
        result <- gtk_expression_ref self'
        checkUnexpectedReturnNULL "expressionRef" result
        result' <- (wrapPtr Expression) result
        touchManagedPtr self
        return result'

    #if defined(ENABLE_OVERLOADING)
    data ExpressionRefMethodInfo
    instance (signature ~ (m Expression), MonadIO m, IsExpression a) => O.OverloadedMethod ExpressionRefMethodInfo a signature where
        overloadedMethod = expressionRef

    instance O.OverloadedMethodInfo ExpressionRefMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionRef",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionRef"
            })

    #endif

    -- method Expression::unref
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferEverything
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Nothing
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_unref" gtk_expression_unref ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        IO ()

    -- | Releases a reference on the given @GtkExpression@.
    --
    -- If the reference was the last, the resources associated to the @self@ are
    -- freed.
    expressionUnref ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> m ()
    expressionUnref :: forall (m :: * -> *) a.
    (HasCallStack, MonadIO m, IsExpression a) =>
    a -> m ()
    expressionUnref a
    self = IO () -> m ()
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO () -> m ()) -> IO () -> m ()
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    B.ManagedPtr.disownManagedPtr a
    self
        gtk_expression_unref self'
        touchManagedPtr self
        return ()

    #if defined(ENABLE_OVERLOADING)
    data ExpressionUnrefMethodInfo
    instance (signature ~ (m ()), MonadIO m, IsExpression a) => O.OverloadedMethod ExpressionUnrefMethodInfo a signature where
        overloadedMethod = expressionUnref

    instance O.OverloadedMethodInfo ExpressionUnrefMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionUnref",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionUnref"
            })

    #endif

    -- method Expression::watch
    -- method type : OrdinaryMethod
    -- Args: [ Arg
    --           { argCName = "self"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "Expression" }
    --           , argCType = Just "GtkExpression*"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "a `GtkExpression`" , sinceVersion = Nothing }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "this_"
    --           , argType =
    --               TInterface Name { namespace = "GObject" , name = "Object" }
    --           , argCType = Just "gpointer"
    --           , direction = DirectionIn
    --           , mayBeNull = True
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "the `this` argument to\n  watch"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "notify"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "ExpressionNotify" }
    --           , argCType = Just "GtkExpressionNotify"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText =
    --                     Just "callback to invoke when the expression changes"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeNotified
    --           , argClosure = 3
    --           , argDestroy = 4
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "user_data"
    --           , argType = TBasicType TPtr
    --           , argCType = Just "gpointer"
    --           , direction = DirectionIn
    --           , mayBeNull = True
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "user data to pass to the `notify` callback"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeInvalid
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "user_destroy"
    --           , argType =
    --               TInterface Name { namespace = "GLib" , name = "DestroyNotify" }
    --           , argCType = Just "GDestroyNotify"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText = Just "destroy notify for `user_data`"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeAsync
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just
    --               (TInterface Name { namespace = "Gtk" , name = "ExpressionWatch" })
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_expression_watch" gtk_expression_watch ::
        Ptr Expression ->                       -- self : TInterface (Name {namespace = "Gtk", name = "Expression"})
        Ptr GObject.Object.Object ->            -- this_ : TInterface (Name {namespace = "GObject", name = "Object"})
        FunPtr Gtk.Callbacks.C_ExpressionNotify -> -- notify : TInterface (Name {namespace = "Gtk", name = "ExpressionNotify"})
        Ptr () ->                               -- user_data : TBasicType TPtr
        FunPtr GLib.Callbacks.C_DestroyNotify -> -- user_destroy : TInterface (Name {namespace = "GLib", name = "DestroyNotify"})
        IO (Ptr Gtk.ExpressionWatch.ExpressionWatch)

    -- | Watch the given @expression@ for changes.
    --
    -- The /@notify@/ function will be called whenever the evaluation of @self@
    -- may have changed.
    --
    -- GTK cannot guarantee that the evaluation did indeed change when the /@notify@/
    -- gets invoked, but it guarantees the opposite: When it did in fact change,
    -- the /@notify@/ will be invoked.
    expressionWatch ::
        (B.CallStack.HasCallStack, MonadIO m, IsExpression a, GObject.Object.IsObject b) =>
        a
        -- ^ /@self@/: a @GtkExpression@
        -> Maybe (b)
        -- ^ /@this_@/: the @this@ argument to
        --   watch
        -> Gtk.Callbacks.ExpressionNotify
        -- ^ /@notify@/: callback to invoke when the expression changes
        -> m Gtk.ExpressionWatch.ExpressionWatch
        -- ^ __Returns:__ The newly installed watch. Note that the only
        --   reference held to the watch will be released when the watch is unwatched
        --   which can happen automatically, and not just via
        --   'GI.Gtk.Structs.ExpressionWatch.expressionWatchUnwatch'. You should call 'GI.Gtk.Structs.ExpressionWatch.expressionWatchRef'
        --   if you want to keep the watch around.
    expressionWatch :: forall (m :: * -> *) a b.
    (HasCallStack, MonadIO m, IsExpression a, IsObject b) =>
    a -> Maybe b -> IO () -> m ExpressionWatch
    expressionWatch a
    self Maybe b
    this_ IO ()
    notify = IO ExpressionWatch -> m ExpressionWatch
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO ExpressionWatch -> m ExpressionWatch)
    -> IO ExpressionWatch -> m ExpressionWatch
    forall a b. (a -> b) -> a -> b
    $ do
        self' <- a -> IO (Ptr Expression)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr a
    self
        maybeThis_ <- case this_ of
            Maybe b
    Nothing -> Ptr Object -> IO (Ptr Object)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return Ptr Object
    forall a. Ptr a
    FP.nullPtr
            Just b
    jThis_ -> do
                jThis_' <- b -> IO (Ptr Object)
    forall a b. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr b)
    unsafeManagedPtrCastPtr b
    jThis_
                return jThis_'
        notify' <- Gtk.Callbacks.mk_ExpressionNotify (Gtk.Callbacks.wrap_ExpressionNotify Nothing (Gtk.Callbacks.drop_closures_ExpressionNotify notify))
        let userData = FunPtr C_ExpressionNotify -> Ptr ()
    forall a b. FunPtr a -> Ptr b
    castFunPtrToPtr FunPtr C_ExpressionNotify
    notify'
        let userDestroy = FunPtr (Ptr a -> IO ())
    forall a. FunPtr (Ptr a -> IO ())
    SP.safeFreeFunPtrPtr
        result <- gtk_expression_watch self' maybeThis_ notify' userData userDestroy
        checkUnexpectedReturnNULL "expressionWatch" result
        result' <- (newBoxed Gtk.ExpressionWatch.ExpressionWatch) result
        touchManagedPtr self
        whenJust this_ touchManagedPtr
        return result'

    #if defined(ENABLE_OVERLOADING)
    data ExpressionWatchMethodInfo
    instance (signature ~ (Maybe (b) -> Gtk.Callbacks.ExpressionNotify -> m Gtk.ExpressionWatch.ExpressionWatch), MonadIO m, IsExpression a, GObject.Object.IsObject b) => O.OverloadedMethod ExpressionWatchMethodInfo a signature where
        overloadedMethod = expressionWatch

    instance O.OverloadedMethodInfo ExpressionWatchMethodInfo a where
        overloadedMethodInfo = P.Just (O.ResolvedSymbolInfo {
            O.resolvedSymbolName = "GI.Gtk.Objects.Expression.expressionWatch",
            O.resolvedSymbolURL = "https://hackage.haskell.org/package/gi-gtk4-4.0.12/docs/GI-Gtk-Objects-Expression.html#v:expressionWatch"
            })

    #endif