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|
{-# LANGUAGE CPP #-}
-- -*-haskell-*-
-- GIMP Toolkit (GTK) Cairo GDK integration
--
-- Author : Duncan Coutts
--
-- Created: 17 August 2005
--
-- Copyright (C) 2005 Duncan Coutts
--
-- This library is free software; you can redistribute it and/or
-- modify it under the terms of the GNU Lesser General Public
-- License as published by the Free Software Foundation; either
-- version 2.1 of the License, or (at your option) any later version.
--
-- This library is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-- Lesser General Public License for more details.
--
-- #hide
-- |
-- Maintainer : gtk2hs-users@lists.sourceforge.net
-- Stability : provisional
-- Portability : portable (depends on GHC)
--
--
-- Gtk specific functions to for rendering with Cairo.
--
-- Cairo is a graphics library that supports vector graphics and image
-- compositing that can be used with Gdk.
-- The Cairo API is an addition to Gdk\/Gtk (rather than a replacement).
-- Cairo rendering can be performed on any 'Graphics.UI.Gtk.Gdk.Drawable'
-- by calling 'renderWithDrawable'. The functions in this module provide
-- ways of drawing Gtk specific elements, such as 'Pixbuf's or text
-- laid out with Pango.
--
-- All functions in this module are only available in Gtk 2.8 or higher.
--
module Graphics.UI.Gtk.Cairo (
#if GTK_CHECK_VERSION(2,8,0)
-- * Global Cairo settings.
cairoFontMapGetDefault,
cairoFontMapSetResolution,
cairoFontMapGetResolution,
cairoCreateContext,
cairoContextSetResolution,
cairoContextGetResolution,
cairoContextSetFontOptions,
cairoContextGetFontOptions,
-- * Functions for the 'Render' monad.
#if GTK_MAJOR_VERSION < 3
renderWithDrawable,
#else
getClipRectangle,
renderWithDrawWindow,
#endif
region,
setSourceColor,
setSourcePixbuf,
rectangle,
updateContext,
createLayout,
updateLayout,
showGlyphString,
showLayoutLine,
showLayout,
glyphStringPath,
layoutLinePath,
layoutPath
#endif
) where
import Control.Exception (bracket)
import System.Glib.FFI
{#import Graphics.UI.Gtk.Types#}
#if GTK_MAJOR_VERSION < 3
{#import Graphics.UI.Gtk.Gdk.Region#} (Region(..))
#endif
{#import Graphics.Rendering.Pango.Cairo#}
#if GTK_CHECK_VERSION(2,8,0)
#if GTK_MAJOR_VERSION < 3
{#import Graphics.Rendering.Cairo.Types#} as Cairo hiding (Region)
#else
{#import Graphics.Rendering.Cairo.Types#} as Cairo
#endif
import qualified Graphics.Rendering.Cairo.Internal as Cairo.Internal
import Graphics.Rendering.Cairo.Internal (Render(Render))
import Control.Monad.Reader
import Graphics.UI.Gtk.General.Structs (Rectangle(..))
#endif
{# context lib="gdk" prefix="gdk" #}
--------------------
-- Methods
#if GTK_CHECK_VERSION(2,8,0)
#if GTK_MAJOR_VERSION < 3
-- | Creates a Cairo context for drawing to a 'Drawable'.
--
-- Removed in Gtk3.
renderWithDrawable :: DrawableClass drawable =>
drawable -- ^ @drawable@ - a 'Drawable'
-> Render a -- ^ A newly created Cairo context.
-> IO a
renderWithDrawable drawable m =
bracket (liftM Cairo.Cairo $ {#call unsafe gdk_cairo_create#} (toDrawable drawable))
(\context -> do status <- Cairo.Internal.status context
Cairo.Internal.destroy context
unless (status == Cairo.StatusSuccess) $
fail =<< Cairo.Internal.statusToString status)
(\context -> runReaderT (Cairo.Internal.runRender m) context)
#endif
#if GTK_MAJOR_VERSION >= 3
-- | Creates a Cairo context for drawing to a 'DrawWindow'.
renderWithDrawWindow :: DrawWindowClass drawWindow =>
drawWindow -- ^ @drawWindow@ - a 'DrawWindow'
-> Render a -- ^ A newly created Cairo context.
-> IO a
renderWithDrawWindow drawWindow m =
bracket (liftM Cairo.Cairo $ {#call unsafe gdk_cairo_create#} (toDrawWindow drawWindow))
(\context -> do status <- Cairo.Internal.status context
Cairo.Internal.destroy context
unless (status == Cairo.StatusSuccess) $
fail =<< Cairo.Internal.statusToString status)
(\context -> runReaderT (Cairo.Internal.runRender m) context)
-- | Compute a bounding box in user coordinates covering the area inside
-- the current clip. It rounds the bounding box to integer coordinates.
-- Returns 'Nothing' indicating if a clip area doesn't exist.
getClipRectangle :: Render (Maybe Rectangle)
getClipRectangle = Render $ do
cr <- ask
liftIO $ alloca $ \rectPtr -> do
ok <- {# call unsafe gdk_cairo_get_clip_rectangle #}
cr
(castPtr rectPtr)
if ok /= 0
then fmap Just (peek rectPtr)
else return Nothing
#endif
-- | Sets the given pixbuf as the source pattern for the Cairo context. The
-- pattern has an extend mode of 'ExtendNone' and is aligned so that the
-- origin of pixbuf is @(x, y)@.
--
setSourcePixbuf ::
Pixbuf
-> Double -- ^ x
-> Double -- ^ y
-> Render ()
setSourcePixbuf pixbuf pixbufX pixbufY = Render $ do
cr <- ask
liftIO $ {# call unsafe gdk_cairo_set_source_pixbuf #}
cr
pixbuf
(realToFrac pixbufX)
(realToFrac pixbufY)
-- | Adds the given region to the current path of the 'Render' context.
rectangle :: Rectangle -> Render ()
rectangle rect = Render $ do
cr <- ask
liftIO $ with rect $ \ rectPtr ->
{# call unsafe gdk_cairo_rectangle #}
cr
(castPtr rectPtr)
-- | Adds the given region to the current path of the 'Render' context.
region :: Region -> Render ()
region region = Render $ do
cr <- ask
liftIO $ {# call unsafe gdk_cairo_region #}
cr
region
#endif
|
