diagrams-cairo-0.6: Cairo backend for diagrams drawing EDSL

Safe HaskellNone



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.



data Cairo Source

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 know way to know which backend you wanted to use, and (2) as an argument to the Backend and Renderable type classes.



data OutputType Source

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.



Portable Network Graphics output.


PostScript output


Portable Document Format output.


Scalable Vector Graphics output.


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)

type RenderM a = StateT () Render aSource

The custom monad in which intermediate drawing options take place; Render is cairo's own rendering monad. At one point RenderM really did use StateT, but then the state got taken out... but the StateT remains, now with a zen-like state of type unit, "just in case". Think of it as a good luck charm.

save :: RenderM ()Source

Push the current context onto a stack.

restore :: RenderM ()Source

Restore the context from a stack.

renderC :: (Renderable a Cairo, V a ~ R2) => a -> RenderM ()Source

cairoMiscStyle :: Style v -> RenderM ()Source

Handle "miscellaneous" style attributes (clip, font stuff, fill color and fill rule).

cairoStrokeStyle :: Style v -> Render ()Source

Handle style attributes having to do with stroke.

setSource :: Color c => c -> Style v -> Render ()Source

cairoTransf :: T2 -> Render ()Source

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