    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Graphics.Rendering.Chart.Axis.Unit
    -- Copyright   :  (c) Tim Docker 2010
    -- License     :  BSD-style (see chart/COPYRIGHT)
    --
    -- Calculate and render unit indexed axes
    {-# OPTIONS_GHC -fno-warn-orphans #-}

    module Graphics.Rendering.Chart.Axis.Unit(
        unitAxis,
    ) where

    import Data.Default.Class

    import Graphics.Rendering.Chart.Axis.Types

    instance PlotValue () where
        toValue () = 0
        fromValue  = const ()
        autoAxis   = const unitAxis

    unitAxis :: AxisData ()
    unitAxis = AxisData {
        _axis_visibility = def
                         { _axis_show_ticks  = False
                         , _axis_show_labels = False
                         },
        _axis_viewport = \(x0,x1) _ -> (x0+x1)/2,
        _axis_tropweiv = \_       _ -> (),
        _axis_ticks    = [((), 0)],
        _axis_labels   = [[((), "")]],
        _axis_grid     = []
    }