Graphics.Layout.CSS.Length

Infrastructure for parsing & desugaring length units & keywords, in reference to the selected font.

Documentation

type Unitted = (Double, Text)

A number+unit, prior to resolving side units. The unit may alternately represent a keyword, in which case the number is ignored & typically set to 0.

auto :: Unitted

The CSS auto keyword.

parseLength :: [Token] -> Maybe Unitted

Parse a pre-tokenized CSS length value.

parseLength' :: [Token] -> Maybe (Double, Text)

Variant of parseLength which supports min-content & max-content keywords.

n2f :: (Fractional x, RealFloat x) => NumericValue -> x

Convert a lexed number to a Double.

finalizeLength :: Unitted -> Font' -> Length

Resolve a parsed length according to the sizing parameters in a given Font`.

px2pt :: Font' -> Double -> Double

Convert from a computed length to the "pt" unit.

data Font'

A Harfbuzz font with sizing parameters.

Constructors

Font'

Fields

• hbFont :: Font

  The Harfbuzz font used to shape text & query character-size information.

• pattern :: Pattern

  The FontConfig query result. Useful to incorporate into output rendering.

• fontHeight :: Char -> Double

  Query the height of a character. Used for cap, ex, or ic units.

• fontAdvance :: Char -> Double

  Query the width of a character, used for ch unit.

• fontSize :: Double

  The desired font-size, used for em unit.

• rootEm :: Double

  The root font's size, used for rem unit.

• lineheight :: Double

  The desired line-height, used for lh unit.

• rlh :: Double

  The root font's line-height, used for rlh unit.

• vh :: Double

  Scale-factor for vh unit.

• vw :: Double

  Scale-factor for vw unit.

• vmax :: Double

  Scale-factor for vmax unit.

• vmin :: Double

  Scale-factor for vmin unit.

• scale :: Double

  How many device pixels in a CSS px?

Instances

Eq Font'

Defined in Graphics.Layout.CSS.Length

Methods

(==) :: Font' -> Font' -> Bool

(/=) :: Font' -> Font' -> Bool

(PropertyParser x, Zero m, Zero n) => Default (UserData m n x)

Defined in Graphics.Layout.CSS

Methods

def :: UserData m n x