    {-# LANGUAGE TypeApplications #-}

    -- | Copyright  : Will Thompson and Iñaki García Etxebarria
    -- License    : LGPL-2.1
    -- Maintainer : Iñaki García Etxebarria
    --
    -- Uses closures for size negotiation.
    --
    -- A @GtkCustomLayout@ uses closures matching to the old @GtkWidget@
    -- virtual functions for size negotiation, as a convenience API to
    -- ease the porting towards the corresponding @GtkLayoutManager@
    -- virtual functions.

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

    module GI.Gtk.Objects.CustomLayout
        (

    -- * Exported types
        CustomLayout(..)                        ,
        IsCustomLayout                          ,
        toCustomLayout                          ,

     -- * Methods
    -- |
    --
    --  === __Click to display all available methods, including inherited ones__
    -- ==== Methods
    -- [allocate]("GI.Gtk.Objects.LayoutManager#g:method:allocate"), [bindProperty]("GI.GObject.Objects.Object#g:method:bindProperty"), [bindPropertyFull]("GI.GObject.Objects.Object#g:method:bindPropertyFull"), [forceFloating]("GI.GObject.Objects.Object#g:method:forceFloating"), [freezeNotify]("GI.GObject.Objects.Object#g:method:freezeNotify"), [getv]("GI.GObject.Objects.Object#g:method:getv"), [isFloating]("GI.GObject.Objects.Object#g:method:isFloating"), [layoutChanged]("GI.Gtk.Objects.LayoutManager#g:method:layoutChanged"), [measure]("GI.Gtk.Objects.LayoutManager#g:method:measure"), [notify]("GI.GObject.Objects.Object#g:method:notify"), [notifyByPspec]("GI.GObject.Objects.Object#g:method:notifyByPspec"), [ref]("GI.GObject.Objects.Object#g:method:ref"), [refSink]("GI.GObject.Objects.Object#g:method:refSink"), [runDispose]("GI.GObject.Objects.Object#g:method:runDispose"), [stealData]("GI.GObject.Objects.Object#g:method:stealData"), [stealQdata]("GI.GObject.Objects.Object#g:method:stealQdata"), [thawNotify]("GI.GObject.Objects.Object#g:method:thawNotify"), [unref]("GI.GObject.Objects.Object#g:method:unref"), [watchClosure]("GI.GObject.Objects.Object#g:method:watchClosure").
    --
    -- ==== Getters
    -- [getData]("GI.GObject.Objects.Object#g:method:getData"), [getLayoutChild]("GI.Gtk.Objects.LayoutManager#g:method:getLayoutChild"), [getProperty]("GI.GObject.Objects.Object#g:method:getProperty"), [getQdata]("GI.GObject.Objects.Object#g:method:getQdata"), [getRequestMode]("GI.Gtk.Objects.LayoutManager#g:method:getRequestMode"), [getWidget]("GI.Gtk.Objects.LayoutManager#g:method:getWidget").
    --
    -- ==== Setters
    -- [setData]("GI.GObject.Objects.Object#g:method:setData"), [setDataFull]("GI.GObject.Objects.Object#g:method:setDataFull"), [setProperty]("GI.GObject.Objects.Object#g:method:setProperty").

    #if defined(ENABLE_OVERLOADING)
        ResolveCustomLayoutMethod               ,
    #endif

    -- ** new #method:new#

        customLayoutNew                         ,

        ) 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.Cairo.Structs.Context as Cairo.Context
    import qualified GI.Cairo.Structs.FontOptions as Cairo.FontOptions
    import qualified GI.GLib.Callbacks as GLib.Callbacks
    import qualified GI.GLib.Structs.Bytes as GLib.Bytes
    import qualified GI.GObject.Objects.Object as GObject.Object
    import qualified GI.Gdk.Flags as Gdk.Flags
    import qualified GI.Gdk.Interfaces.Paintable as Gdk.Paintable
    import qualified GI.Gdk.Objects.Clipboard as Gdk.Clipboard
    import qualified GI.Gdk.Objects.Cursor as Gdk.Cursor
    import qualified GI.Gdk.Objects.Device as Gdk.Device
    import qualified GI.Gdk.Objects.Display as Gdk.Display
    import qualified GI.Gdk.Objects.Event as Gdk.Event
    import qualified GI.Gdk.Objects.FrameClock as Gdk.FrameClock
    import qualified GI.Gdk.Objects.Snapshot as Gdk.Snapshot
    import qualified GI.Gdk.Objects.Surface as Gdk.Surface
    import qualified GI.Gdk.Objects.Texture as Gdk.Texture
    import qualified GI.Gdk.Structs.RGBA as Gdk.RGBA
    import qualified GI.Gdk.Structs.Rectangle as Gdk.Rectangle
    import qualified GI.Gio.Interfaces.ActionGroup as Gio.ActionGroup
    import qualified GI.Gio.Interfaces.Icon as Gio.Icon
    import qualified GI.Gio.Interfaces.ListModel as Gio.ListModel
    import qualified GI.Graphene.Structs.Matrix as Graphene.Matrix
    import qualified GI.Graphene.Structs.Point as Graphene.Point
    import qualified GI.Graphene.Structs.Point3D as Graphene.Point3D
    import qualified GI.Graphene.Structs.Rect as Graphene.Rect
    import qualified GI.Graphene.Structs.Size as Graphene.Size
    import qualified GI.Graphene.Structs.Vec3 as Graphene.Vec3
    import qualified GI.Graphene.Structs.Vec4 as Graphene.Vec4
    import qualified GI.Gsk.Enums as Gsk.Enums
    import qualified GI.Gsk.Flags as Gsk.Flags
    import qualified GI.Gsk.Objects.GLShader as Gsk.GLShader
    import qualified GI.Gsk.Objects.RenderNode as Gsk.RenderNode
    import qualified GI.Gsk.Objects.Renderer as Gsk.Renderer
    import qualified GI.Gsk.Structs.ColorStop as Gsk.ColorStop
    import qualified GI.Gsk.Structs.ComponentTransfer as Gsk.ComponentTransfer
    import qualified GI.Gsk.Structs.Path as Gsk.Path
    import qualified GI.Gsk.Structs.RoundedRect as Gsk.RoundedRect
    import qualified GI.Gsk.Structs.Shadow as Gsk.Shadow
    import qualified GI.Gsk.Structs.Stroke as Gsk.Stroke
    import qualified GI.Gsk.Structs.Transform as Gsk.Transform
    import qualified GI.Gtk.Callbacks as Gtk.Callbacks
    import {-# SOURCE #-} qualified GI.Gtk.Enums as Gtk.Enums
    import {-# SOURCE #-} qualified GI.Gtk.Flags as Gtk.Flags
    import {-# SOURCE #-} qualified GI.Gtk.Interfaces.Accessible as Gtk.Accessible
    import {-# SOURCE #-} qualified GI.Gtk.Interfaces.Buildable as Gtk.Buildable
    import {-# SOURCE #-} qualified GI.Gtk.Interfaces.ConstraintTarget as Gtk.ConstraintTarget
    import {-# SOURCE #-} qualified GI.Gtk.Interfaces.Native as Gtk.Native
    import {-# SOURCE #-} qualified GI.Gtk.Interfaces.Root as Gtk.Root
    import {-# SOURCE #-} qualified GI.Gtk.Interfaces.StyleProvider as Gtk.StyleProvider
    import {-# SOURCE #-} qualified GI.Gtk.Objects.ATContext as Gtk.ATContext
    import {-# SOURCE #-} qualified GI.Gtk.Objects.EventController as Gtk.EventController
    import {-# SOURCE #-} qualified GI.Gtk.Objects.LayoutChild as Gtk.LayoutChild
    import {-# SOURCE #-} qualified GI.Gtk.Objects.LayoutManager as Gtk.LayoutManager
    import {-# SOURCE #-} qualified GI.Gtk.Objects.Settings as Gtk.Settings
    import {-# SOURCE #-} qualified GI.Gtk.Objects.Snapshot as Gtk.Snapshot
    import {-# SOURCE #-} qualified GI.Gtk.Objects.StyleContext as Gtk.StyleContext
    import {-# SOURCE #-} qualified GI.Gtk.Objects.Tooltip as Gtk.Tooltip
    import {-# SOURCE #-} qualified GI.Gtk.Objects.Widget as Gtk.Widget
    import {-# SOURCE #-} qualified GI.Gtk.Structs.Border as Gtk.Border
    import {-# SOURCE #-} qualified GI.Gtk.Structs.Requisition as Gtk.Requisition
    import qualified GI.Pango.Enums as Pango.Enums
    import qualified GI.Pango.Objects.Context as Pango.Context
    import qualified GI.Pango.Objects.FontMap as Pango.FontMap
    import qualified GI.Pango.Objects.Layout as Pango.Layout

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

    #endif

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

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

    foreign import ccall "gtk_custom_layout_get_type"
        c_gtk_custom_layout_get_type :: IO B.Types.GType

    instance B.Types.TypedObject CustomLayout where
        glibType :: IO GType
    glibType = IO GType
    c_gtk_custom_layout_get_type

    instance B.Types.GObject CustomLayout

    -- | Type class for types which can be safely cast to t'CustomLayout', for instance with `toCustomLayout`.
    class (SP.GObject o, O.IsDescendantOf CustomLayout o) => IsCustomLayout o
    instance (SP.GObject o, O.IsDescendantOf CustomLayout o) => IsCustomLayout o

    instance O.HasParentTypes CustomLayout
    type instance O.ParentTypes CustomLayout = '[Gtk.LayoutManager.LayoutManager, GObject.Object.Object]

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

    -- | Convert t'CustomLayout' 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 CustomLayout) where
        gvalueGType_ :: IO GType
    gvalueGType_ = IO GType
    c_gtk_custom_layout_get_type
        gvalueSet_ :: Ptr GValue -> Maybe CustomLayout -> IO ()
    gvalueSet_ Ptr GValue
    gv Maybe CustomLayout
    P.Nothing = Ptr GValue -> Ptr CustomLayout -> IO ()
    forall a. GObject a => Ptr GValue -> Ptr a -> IO ()
    B.GValue.set_object Ptr GValue
    gv (Ptr CustomLayout
    forall a. Ptr a
    FP.nullPtr :: FP.Ptr CustomLayout)
        gvalueSet_ Ptr GValue
    gv (P.Just CustomLayout
    obj) = CustomLayout -> (Ptr CustomLayout -> IO ()) -> IO ()
    forall a c.
    (HasCallStack, ManagedPtrNewtype a) =>
    a -> (Ptr a -> IO c) -> IO c
    B.ManagedPtr.withManagedPtr CustomLayout
    obj (Ptr GValue -> Ptr CustomLayout -> IO ()
    forall a. GObject a => Ptr GValue -> Ptr a -> IO ()
    B.GValue.set_object Ptr GValue
    gv)
        gvalueGet_ :: Ptr GValue -> IO (Maybe CustomLayout)
    gvalueGet_ Ptr GValue
    gv = do
            ptr <- Ptr GValue -> IO (Ptr CustomLayout)
    forall a. GObject a => Ptr GValue -> IO (Ptr a)
    B.GValue.get_object Ptr GValue
    gv :: IO (FP.Ptr CustomLayout)
            if ptr /= FP.nullPtr
            then P.Just <$> B.ManagedPtr.newObject CustomLayout ptr
            else return P.Nothing

    #if defined(ENABLE_OVERLOADING)
    type family ResolveCustomLayoutMethod (t :: Symbol) (o :: DK.Type) :: DK.Type where
        ResolveCustomLayoutMethod "allocate" o = Gtk.LayoutManager.LayoutManagerAllocateMethodInfo
        ResolveCustomLayoutMethod "bindProperty" o = GObject.Object.ObjectBindPropertyMethodInfo
        ResolveCustomLayoutMethod "bindPropertyFull" o = GObject.Object.ObjectBindPropertyFullMethodInfo
        ResolveCustomLayoutMethod "forceFloating" o = GObject.Object.ObjectForceFloatingMethodInfo
        ResolveCustomLayoutMethod "freezeNotify" o = GObject.Object.ObjectFreezeNotifyMethodInfo
        ResolveCustomLayoutMethod "getv" o = GObject.Object.ObjectGetvMethodInfo
        ResolveCustomLayoutMethod "isFloating" o = GObject.Object.ObjectIsFloatingMethodInfo
        ResolveCustomLayoutMethod "layoutChanged" o = Gtk.LayoutManager.LayoutManagerLayoutChangedMethodInfo
        ResolveCustomLayoutMethod "measure" o = Gtk.LayoutManager.LayoutManagerMeasureMethodInfo
        ResolveCustomLayoutMethod "notify" o = GObject.Object.ObjectNotifyMethodInfo
        ResolveCustomLayoutMethod "notifyByPspec" o = GObject.Object.ObjectNotifyByPspecMethodInfo
        ResolveCustomLayoutMethod "ref" o = GObject.Object.ObjectRefMethodInfo
        ResolveCustomLayoutMethod "refSink" o = GObject.Object.ObjectRefSinkMethodInfo
        ResolveCustomLayoutMethod "runDispose" o = GObject.Object.ObjectRunDisposeMethodInfo
        ResolveCustomLayoutMethod "stealData" o = GObject.Object.ObjectStealDataMethodInfo
        ResolveCustomLayoutMethod "stealQdata" o = GObject.Object.ObjectStealQdataMethodInfo
        ResolveCustomLayoutMethod "thawNotify" o = GObject.Object.ObjectThawNotifyMethodInfo
        ResolveCustomLayoutMethod "unref" o = GObject.Object.ObjectUnrefMethodInfo
        ResolveCustomLayoutMethod "watchClosure" o = GObject.Object.ObjectWatchClosureMethodInfo
        ResolveCustomLayoutMethod "getData" o = GObject.Object.ObjectGetDataMethodInfo
        ResolveCustomLayoutMethod "getLayoutChild" o = Gtk.LayoutManager.LayoutManagerGetLayoutChildMethodInfo
        ResolveCustomLayoutMethod "getProperty" o = GObject.Object.ObjectGetPropertyMethodInfo
        ResolveCustomLayoutMethod "getQdata" o = GObject.Object.ObjectGetQdataMethodInfo
        ResolveCustomLayoutMethod "getRequestMode" o = Gtk.LayoutManager.LayoutManagerGetRequestModeMethodInfo
        ResolveCustomLayoutMethod "getWidget" o = Gtk.LayoutManager.LayoutManagerGetWidgetMethodInfo
        ResolveCustomLayoutMethod "setData" o = GObject.Object.ObjectSetDataMethodInfo
        ResolveCustomLayoutMethod "setDataFull" o = GObject.Object.ObjectSetDataFullMethodInfo
        ResolveCustomLayoutMethod "setProperty" o = GObject.Object.ObjectSetPropertyMethodInfo
        ResolveCustomLayoutMethod l o = O.MethodResolutionFailed l o

    instance (info ~ ResolveCustomLayoutMethod t CustomLayout, O.OverloadedMethod info CustomLayout p) => OL.IsLabel t (CustomLayout -> 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 ~ ResolveCustomLayoutMethod t CustomLayout, O.OverloadedMethod info CustomLayout p, R.HasField t CustomLayout p) => R.HasField t CustomLayout p where
        getField = O.overloadedMethod @info

    #endif

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

    #endif

    #if defined(ENABLE_OVERLOADING)
    instance O.HasAttributeList CustomLayout
    type instance O.AttributeList CustomLayout = CustomLayoutAttributeList
    type CustomLayoutAttributeList = ('[ ] :: [(Symbol, DK.Type)])
    #endif

    #if defined(ENABLE_OVERLOADING)
    #endif

    #if defined(ENABLE_OVERLOADING)
    type instance O.SignalList CustomLayout = CustomLayoutSignalList
    type CustomLayoutSignalList = ('[ '("notify", GObject.Object.ObjectNotifySignalInfo)] :: [(Symbol, DK.Type)])

    #endif

    -- method CustomLayout::new
    -- method type : Constructor
    -- Args: [ Arg
    --           { argCName = "request_mode"
    --           , argType =
    --               TInterface
    --                 Name { namespace = "Gtk" , name = "CustomRequestModeFunc" }
    --           , argCType = Just "GtkCustomRequestModeFunc"
    --           , direction = DirectionIn
    --           , mayBeNull = True
    --           , argDoc =
    --               Documentation
    --                 { rawDocText =
    --                     Just
    --                       "a function to retrieve\n  the `GtkSizeRequestMode` of the widget using the layout; the\n  default request mode is %GTK_SIZE_REQUEST_CONSTANT_SIZE"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeCall
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "measure"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "CustomMeasureFunc" }
    --           , argCType = Just "GtkCustomMeasureFunc"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText =
    --                     Just "a function to measure the widget using the layout manager"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeCall
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       , Arg
    --           { argCName = "allocate"
    --           , argType =
    --               TInterface Name { namespace = "Gtk" , name = "CustomAllocateFunc" }
    --           , argCType = Just "GtkCustomAllocateFunc"
    --           , direction = DirectionIn
    --           , mayBeNull = False
    --           , argDoc =
    --               Documentation
    --                 { rawDocText =
    --                     Just
    --                       "a function to allocate the children of the widget using\n  the layout manager"
    --                 , sinceVersion = Nothing
    --                 }
    --           , argScope = ScopeTypeCall
    --           , argClosure = -1
    --           , argDestroy = -1
    --           , argCallerAllocates = False
    --           , argCallbackUserData = False
    --           , transfer = TransferNothing
    --           }
    --       ]
    -- Lengths: []
    -- returnType: Just
    --               (TInterface Name { namespace = "Gtk" , name = "CustomLayout" })
    -- throws : False
    -- Skip return : False

    foreign import ccall "gtk_custom_layout_new" gtk_custom_layout_new ::
        FunPtr Gtk.Callbacks.C_CustomRequestModeFunc -> -- request_mode : TInterface (Name {namespace = "Gtk", name = "CustomRequestModeFunc"})
        FunPtr Gtk.Callbacks.C_CustomMeasureFunc -> -- measure : TInterface (Name {namespace = "Gtk", name = "CustomMeasureFunc"})
        FunPtr Gtk.Callbacks.C_CustomAllocateFunc -> -- allocate : TInterface (Name {namespace = "Gtk", name = "CustomAllocateFunc"})
        IO (Ptr CustomLayout)

    -- | Creates a new legacy layout manager.
    --
    -- Legacy layout managers map to the old @GtkWidget@ size negotiation
    -- virtual functions, and are meant to be used during the transition
    -- from layout containers to layout manager delegates.
    customLayoutNew ::
        (B.CallStack.HasCallStack, MonadIO m) =>
        Maybe (Gtk.Callbacks.CustomRequestModeFunc)
        -- ^ /@requestMode@/: a function to retrieve
        --   the @GtkSizeRequestMode@ of the widget using the layout; the
        --   default request mode is 'GI.Gtk.Enums.SizeRequestModeConstantSize'
        -> Gtk.Callbacks.CustomMeasureFunc
        -- ^ /@measure@/: a function to measure the widget using the layout manager
        -> Gtk.Callbacks.CustomAllocateFunc
        -- ^ /@allocate@/: a function to allocate the children of the widget using
        --   the layout manager
        -> m CustomLayout
        -- ^ __Returns:__ the newly created @GtkCustomLayout@
    customLayoutNew :: forall (m :: * -> *).
    (HasCallStack, MonadIO m) =>
    Maybe CustomRequestModeFunc
    -> CustomMeasureFunc -> CustomAllocateFunc -> m CustomLayout
    customLayoutNew Maybe CustomRequestModeFunc
    requestMode CustomMeasureFunc
    measure CustomAllocateFunc
    allocate = IO CustomLayout -> m CustomLayout
    forall a. IO a -> m a
    forall (m :: * -> *) a. MonadIO m => IO a -> m a
    liftIO (IO CustomLayout -> m CustomLayout)
    -> IO CustomLayout -> m CustomLayout
    forall a b. (a -> b) -> a -> b
    $ do
        maybeRequestMode <- case Maybe CustomRequestModeFunc
    requestMode of
            Maybe CustomRequestModeFunc
    Nothing -> FunPtr C_CustomRequestModeFunc
    -> IO (FunPtr C_CustomRequestModeFunc)
    forall a. a -> IO a
    forall (m :: * -> *) a. Monad m => a -> m a
    return FunPtr C_CustomRequestModeFunc
    forall a. FunPtr a
    FP.nullFunPtr
            Just CustomRequestModeFunc
    jRequestMode -> do
                jRequestMode' <- C_CustomRequestModeFunc -> IO (FunPtr C_CustomRequestModeFunc)
    Gtk.Callbacks.mk_CustomRequestModeFunc (Maybe (Ptr (FunPtr C_CustomRequestModeFunc))
    -> CustomRequestModeFunc -> C_CustomRequestModeFunc
    Gtk.Callbacks.wrap_CustomRequestModeFunc Maybe (Ptr (FunPtr C_CustomRequestModeFunc))
    forall a. Maybe a
    Nothing CustomRequestModeFunc
    jRequestMode)
                return jRequestMode'
        measure' <- Gtk.Callbacks.mk_CustomMeasureFunc (Gtk.Callbacks.wrap_CustomMeasureFunc Nothing measure)
        allocate' <- Gtk.Callbacks.mk_CustomAllocateFunc (Gtk.Callbacks.wrap_CustomAllocateFunc Nothing allocate)
        result <- gtk_custom_layout_new maybeRequestMode measure' allocate'
        checkUnexpectedReturnNULL "customLayoutNew" result
        result' <- (wrapObject CustomLayout) result
        safeFreeFunPtr $ castFunPtrToPtr maybeRequestMode
        safeFreeFunPtr $ castFunPtrToPtr measure'
        safeFreeFunPtr $ castFunPtrToPtr allocate'
        return result'

    #if defined(ENABLE_OVERLOADING)
    #endif