Diagrams.Backend.Cairo.Internal

This module contains the internal implementation guts of the diagrams cairo backend. If you want to see how the cairo backend works under the hood, you are in the right place (try clicking on the "Source" links). (Guts under the hood, what an awful mixed metaphor.) If you know what you are doing and really want access to the internals of the implementation, you are also in the right place. Otherwise, you should have no need of this module; import Diagrams.Backend.Cairo.CmdLine or Diagrams.Backend.Cairo instead.

The one exception is that this module may have to be imported sometimes to work around an apparent bug in certain versions of GHC, which results in a "not in scope" error for CairoOptions.

The types of all the fromX functions look funny in the Haddock output, which displays them like Type -> Type. In fact they are all of the form Type -> Graphics.Rendering.Cairo.Type, i.e. they convert from a diagrams type to a cairo type of the same name.

Documentation

data Cairo

This data declaration is simply used as a token to distinguish the cairo backend: (1) when calling functions where the type inference engine would otherwise have no way to know which backend you wanted to use, and (2) as an argument to the Backend and Renderable type classes.

Constructors

Cairo

Instances

Eq Cairo

Methods

(==) :: Cairo -> Cairo -> Bool

(/=) :: Cairo -> Cairo -> Bool

Ord Cairo

Methods

compare :: Cairo -> Cairo -> Ordering

(<) :: Cairo -> Cairo -> Bool

(<=) :: Cairo -> Cairo -> Bool

(>) :: Cairo -> Cairo -> Bool

(>=) :: Cairo -> Cairo -> Bool

max :: Cairo -> Cairo -> Cairo

min :: Cairo -> Cairo -> Cairo

Read Cairo

Methods

readsPrec :: Int -> ReadS Cairo

readList :: ReadS [Cairo]

readPrec :: ReadPrec Cairo

readListPrec :: ReadPrec [Cairo]

Show Cairo

Methods

showsPrec :: Int -> Cairo -> ShowS

show :: Cairo -> String

showList :: [Cairo] -> ShowS

Backend Cairo V2 Double

Associated Types

data Render Cairo (V2 :: * -> *) Double :: *

type Result Cairo (V2 :: * -> *) Double :: *

data Options Cairo (V2 :: * -> *) Double :: *

Methods

adjustDia :: (Additive V2, Monoid' m, Num Double) => Cairo -> Options Cairo V2 Double -> QDiagram Cairo V2 Double m -> (Options Cairo V2 Double, Transformation V2 Double, QDiagram Cairo V2 Double m)

renderRTree :: Cairo -> Options Cairo V2 Double -> RTree Cairo V2 Double Annotation -> Result Cairo V2 Double

Renderable (Text Double) Cairo

Methods

render :: Cairo -> Text Double -> Render Cairo (V (Text Double)) (N (Text Double))

Renderable (DImage Double Embedded) Cairo

Methods

render :: Cairo -> DImage Double Embedded -> Render Cairo (V (DImage Double Embedded)) (N (DImage Double Embedded))

Renderable (DImage Double External) Cairo

Methods

render :: Cairo -> DImage Double External -> Render Cairo (V (DImage Double External)) (N (DImage Double External))

Renderable (Path V2 Double) Cairo

Methods

render :: Cairo -> Path V2 Double -> Render Cairo (V (Path V2 Double)) (N (Path V2 Double))

Renderable (Trail V2 Double) Cairo

Methods

render :: Cairo -> Trail V2 Double -> Render Cairo (V (Trail V2 Double)) (N (Trail V2 Double))

Show (Options Cairo V2 Double)

Methods

showsPrec :: Int -> Options Cairo V2 Double -> ShowS

show :: Options Cairo V2 Double -> String

showList :: [Options Cairo V2 Double] -> ShowS

Semigroup (Render Cairo V2 Double)

Methods

(<>) :: Render Cairo V2 Double -> Render Cairo V2 Double -> Render Cairo V2 Double

sconcat :: NonEmpty (Render Cairo V2 Double) -> Render Cairo V2 Double

stimes :: Integral b => b -> Render Cairo V2 Double -> Render Cairo V2 Double

Monoid (Render Cairo V2 Double)

Methods

mempty :: Render Cairo V2 Double

mappend :: Render Cairo V2 Double -> Render Cairo V2 Double -> Render Cairo V2 Double

mconcat :: [Render Cairo V2 Double] -> Render Cairo V2 Double

Hashable (Options Cairo V2 Double)

Methods

hashWithSalt :: Int -> Options Cairo V2 Double -> Int

hash :: Options Cairo V2 Double -> Int

Renderable (Segment Closed V2 Double) Cairo

Methods

render :: Cairo -> Segment Closed V2 Double -> Render Cairo (V (Segment Closed V2 Double)) (N (Segment Closed V2 Double))

type V Cairo

type V Cairo = V2

type N Cairo

type N Cairo = Double

data Options Cairo V2 Double

data Options Cairo V2 Double = CairoOptions {

• _cairoFileName :: String
• _cairoSizeSpec :: SizeSpec V2 Double
• _cairoOutputType :: OutputType
• _cairoBypassAdjust :: Bool

}

type Result Cairo V2 Double

type Result Cairo V2 Double = (IO (), Render ())

data Render Cairo V2 Double

data Render Cairo V2 Double = C (RenderM ())

type MainOpts [(String, QDiagram Cairo V2 Double Any)]

type MainOpts [(String, QDiagram Cairo V2 Double Any)] = (MainOpts (QDiagram Cairo V2 Double Any), DiagramMultiOpts)

type MainOpts [(QDiagram Cairo V2 Double Any, GifDelay)]

type MainOpts [(QDiagram Cairo V2 Double Any, GifDelay)] = (DiagramOpts, GifOpts)

type MainOpts (Animation Cairo V2 Double)

type MainOpts (Animation Cairo V2 Double) = ((DiagramOpts, DiagramAnimOpts), DiagramLoopOpts)

type MainOpts (QDiagram Cairo V2 Double Any)

type MainOpts (QDiagram Cairo V2 Double Any) = (DiagramOpts, DiagramLoopOpts)

type B = Cairo

data OutputType

Output types supported by cairo, including four different file types (PNG, PS, PDF, SVG). If you want to output directly to GTK windows, see the diagrams-gtk package.

Constructors

PNG

Portable Network Graphics output.

PS

PostScript output

PDF

Portable Document Format output.

SVG

Scalable Vector Graphics output.

RenderOnly

Don't output any file; the returned IO () action will do nothing, but the Render () action can be used (e.g. to draw to a Gtk window; see the diagrams-gtk package).

Instances

Bounded OutputType

Methods

minBound :: OutputType

maxBound :: OutputType

Enum OutputType

Methods

succ :: OutputType -> OutputType

pred :: OutputType -> OutputType

toEnum :: Int -> OutputType

fromEnum :: OutputType -> Int

enumFrom :: OutputType -> [OutputType]

enumFromThen :: OutputType -> OutputType -> [OutputType]

enumFromTo :: OutputType -> OutputType -> [OutputType]

enumFromThenTo :: OutputType -> OutputType -> OutputType -> [OutputType]

Eq OutputType

Methods

(==) :: OutputType -> OutputType -> Bool

(/=) :: OutputType -> OutputType -> Bool

Ord OutputType

Methods

compare :: OutputType -> OutputType -> Ordering

(<) :: OutputType -> OutputType -> Bool

(<=) :: OutputType -> OutputType -> Bool

(>) :: OutputType -> OutputType -> Bool

(>=) :: OutputType -> OutputType -> Bool

max :: OutputType -> OutputType -> OutputType

min :: OutputType -> OutputType -> OutputType

Read OutputType

Methods

readsPrec :: Int -> ReadS OutputType

readList :: ReadS [OutputType]

readPrec :: ReadPrec OutputType

readListPrec :: ReadPrec [OutputType]

Show OutputType

Methods

showsPrec :: Int -> OutputType -> ShowS

show :: OutputType -> String

showList :: [OutputType] -> ShowS

Generic OutputType

Associated Types

type Rep OutputType :: * -> *

Methods

from :: OutputType -> Rep OutputType x

to :: Rep OutputType x -> OutputType

Hashable OutputType

Methods

hashWithSalt :: Int -> OutputType -> Int

hash :: OutputType -> Int

type Rep OutputType

type Rep OutputType = D1 * (MetaData "OutputType" "Diagrams.Backend.Cairo.Internal" "diagrams-cairo-1.4.1-6NeAt7thgJwHJsUpDRrFPF" False) ((:+:) * ((:+:) * (C1 * (MetaCons "PNG" PrefixI False) (U1 *)) (C1 * (MetaCons "PS" PrefixI False) (U1 *))) ((:+:) * (C1 * (MetaCons "PDF" PrefixI False) (U1 *)) ((:+:) * (C1 * (MetaCons "SVG" PrefixI False) (U1 *)) (C1 * (MetaCons "RenderOnly" PrefixI False) (U1 *)))))

data CairoState

Custom state tracked in the RenderM monad.

Constructors

CairoState

Fields

• _accumStyle :: Style V2 Double

  The current accumulated style.

• _ignoreFill :: Bool

  Whether or not we saw any lines in the most recent path (as opposed to loops). If we did, we should ignore any fill attribute. diagrams-lib separates lines and loops into separate path primitives so we don't have to worry about seeing them together in the same path.

Instances

Default CairoState

Methods

def :: CairoState

ignoreFill :: Lens' CairoState Bool

accumStyle :: Lens' CairoState (Style V2 Double)

type RenderM a = StateStackT CairoState Render a

The custom monad in which intermediate drawing options take place; Render is cairo's own rendering monad.

liftC :: Render a -> RenderM a

runRenderM :: RenderM a -> Render a

save :: RenderM ()

Push the current context onto a stack.

restore :: RenderM ()

Restore the context from a stack.

runC :: Render Cairo V2 Double -> RenderM ()

toRender :: RTree Cairo V2 Double a -> Render Cairo V2 Double

cairoFileName :: Lens' (Options Cairo V2 Double) String

cairoSizeSpec :: Lens' (Options Cairo V2 Double) (SizeSpec V2 Double)

cairoOutputType :: Lens' (Options Cairo V2 Double) OutputType

cairoBypassAdjust :: Lens' (Options Cairo V2 Double) Bool

renderC :: (Renderable a Cairo, V a ~ V2, N a ~ Double) => a -> RenderM ()

Render an object that the cairo backend knows how to render.

getStyleAttrib :: AttributeClass a => (a -> b) -> RenderM (Maybe b)

Get an accumulated style attribute from the render monad state.

cairoStyle :: Style v Double -> RenderM ()

Handle those style attributes for which we can immediately emit cairo instructions as we encounter them in the tree (clip, font size, fill rule, line width, cap, join, and dashing). Other attributes (font face, slant, weight; fill color, stroke color, opacity) must be accumulated.

fromFontSlant :: FontSlant -> FontStyle

fromFontWeight :: FontWeight -> Weight

cairoTransf :: T2 Double -> Render ()

Multiply the current transformation matrix by the given 2D transformation.

fromLineCap :: LineCap -> LineCap

fromLineJoin :: LineJoin -> LineJoin

fromFillRule :: FillRule -> FillRule

cairoPath :: Path V2 Double -> RenderM ()

addStop :: MonadIO m => Pattern -> GradientStop Double -> m ()

cairoSpreadMethod :: SpreadMethod -> Extend

setTexture :: Maybe (Texture Double) -> RenderM ()

toImageRGBA8 :: DynamicImage -> Image PixelRGBA8

toARGB :: PixelRGBA8 -> Word32

if' :: Monad m => (a -> m ()) -> Maybe a -> m ()

layoutStyledText :: Style V2 Double -> Text Double -> Render PangoLayout