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|
{-# LANGUAGE CPP, OverloadedStrings #-}
-- -*-haskell-*-
-- GIMP Toolkit (GTK) Widget PrintContext
--
-- Author : Andy Stewart
--
-- Created: 28 Mar 2010
--
-- Copyright (C) 2010 Andy Stewart
--
-- 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.
--
-- |
-- Maintainer : gtk2hs-users@lists.sourceforge.net
-- Stability : provisional
-- Portability : portable (depends on GHC)
--
-- Encapsulates context for drawing pages
--
-- * Module available since Gtk+ version 2.10
--
module Graphics.UI.Gtk.Printing.PrintContext (
-- * Detail
--
-- | A 'PrintContext' encapsulates context information that is required when
-- drawing pages for printing, such as the cairo context and important
-- parameters like page size and resolution. It also lets you easily create
-- 'PangoLayout' and 'Context' objects that match the font metrics of the cairo
-- surface.
--
-- 'PrintContext' objects gets passed to the 'beginPrint', 'endPrint',
-- 'requestPageSetup' and 'drawPage' signals on the 'PrintOperation'.
--
-- Printing support was added in Gtk+ 2.10.
-- * Class Hierarchy
--
-- |
-- @
-- | 'GObject'
-- | +----PrintContext
-- @
#if GTK_CHECK_VERSION(2,10,0)
-- * Types
PrintContext,
PrintContextClass,
castToPrintContext,
toPrintContext,
-- * Methods
printContextGetCairoContext,
printContextSetCairoContext,
printContextGetPageSetup,
printContextGetWidth,
printContextGetHeight,
printContextGetDpiX,
printContextGetDpiY,
printContextGetPangoFontmap,
printContextCreatePangoContext,
printContextCreatePangoLayout,
#if GTK_CHECK_VERSION(2,20,0)
printContextGetHardMargins,
#endif
#endif
) where
import Control.Monad (liftM)
import Data.IORef (newIORef)
import System.Glib.FFI
import System.Glib.UTFString
{#import Graphics.UI.Gtk.Types#}
{#import Graphics.Rendering.Pango.Types#}
{#import Graphics.Rendering.Pango.BasicTypes#}
{#import Graphics.Rendering.Cairo.Types#}
{# context lib="gtk" prefix="gtk" #}
#if GTK_CHECK_VERSION(2,10,0)
--------------------
-- Methods
-- | Obtains the cairo context that is associated with the 'PrintContext'.
--
printContextGetCairoContext :: PrintContextClass self => self
-> IO Cairo -- ^ returns the cairo context of @context@
printContextGetCairoContext self =
liftM Cairo $
{# call gtk_print_context_get_cairo_context #} (toPrintContext self)
-- | Sets a new cairo context on a print context.
--
-- This function is intended to be used when implementing an internal print
-- preview, it is not needed for printing, since Gtk+ itself creates a suitable
-- cairo context in that case.
--
printContextSetCairoContext :: PrintContextClass self => self
-> Cairo -- ^ @cr@ - the cairo context
-> Double -- ^ @dpiX@ - the horizontal resolution to use with @cr@
-> Double -- ^ @dpiY@ - the vertical resolution to use with @cr@
-> IO ()
printContextSetCairoContext self cr dpiX dpiY =
{# call gtk_print_context_set_cairo_context #}
(toPrintContext self)
cr
(realToFrac dpiX)
(realToFrac dpiY)
-- | Obtains the 'PageSetup' that determines the page dimensions of the
-- 'PrintContext'.
--
printContextGetPageSetup :: PrintContextClass self => self
-> IO PageSetup -- ^ returns the page setup of @context@
printContextGetPageSetup self =
makeNewGObject mkPageSetup $
{# call gtk_print_context_get_page_setup #}
(toPrintContext self)
-- | Obtains the width of the 'PrintContext', in pixels.
--
printContextGetWidth :: PrintContextClass self => self
-> IO Double -- ^ returns the width of @context@
printContextGetWidth self =
liftM realToFrac $
{# call gtk_print_context_get_width #}
(toPrintContext self)
-- | Obtains the height of the 'PrintContext', in pixels.
--
printContextGetHeight :: PrintContextClass self => self
-> IO Double -- ^ returns the height of @context@
printContextGetHeight self =
liftM realToFrac $
{# call gtk_print_context_get_height #}
(toPrintContext self)
-- | Obtains the horizontal resolution of the 'PrintContext', in dots per
-- inch.
--
printContextGetDpiX :: PrintContextClass self => self
-> IO Double -- ^ returns the horizontal resolution of @context@
printContextGetDpiX self =
liftM realToFrac $
{# call gtk_print_context_get_dpi_x #}
(toPrintContext self)
-- | Obtains the vertical resolution of the 'PrintContext', in dots per inch.
--
printContextGetDpiY :: PrintContextClass self => self
-> IO Double -- ^ returns the vertical resolution of @context@
printContextGetDpiY self =
liftM realToFrac $
{# call gtk_print_context_get_dpi_y #}
(toPrintContext self)
-- | Returns a 'FontMap' that is suitable for use with the 'PrintContext'.
--
printContextGetPangoFontmap :: PrintContextClass self => self
-> IO FontMap -- ^ returns the font map of @context@
printContextGetPangoFontmap self =
makeNewGObject mkFontMap $
{# call gtk_print_context_get_pango_fontmap #}
(toPrintContext self)
-- | Creates a new 'Context' that can be used with the 'PrintContext'.
--
printContextCreatePangoContext :: PrintContextClass self => self
-> IO PangoContext -- ^ returns a new Pango context for @context@
printContextCreatePangoContext self =
wrapNewGObject mkPangoContext $
{# call gtk_print_context_create_pango_context #}
(toPrintContext self)
-- | Creates a new 'PangoLayout' that is suitable for use with the
-- 'PrintContext'.
--
printContextCreatePangoLayout :: PrintContextClass self => self
-> IO PangoLayout -- ^ returns a new Pango layout for @context@
printContextCreatePangoLayout self = do
pl <- wrapNewGObject mkPangoLayoutRaw $
{# call gtk_print_context_create_pango_layout #}
(toPrintContext self)
ps <- makeNewPangoString (""::DefaultGlibString)
psRef <- newIORef ps
return (PangoLayout psRef pl)
#if GTK_CHECK_VERSION(2,20,0)
printContextGetHardMargins :: PrintContextClass self => self
-> IO (Maybe (Double, Double, Double, Double))
-- ^ returns @(top, bottom, left, right)@
-- @top@ top hardware printer margin
-- @bottom@ bottom hardware printer margin
-- @left@ left hardware printer margin
-- @right@ right hardware printer margin
printContextGetHardMargins self =
alloca $ \ topPtr ->
alloca $ \ bottomPtr ->
alloca $ \ leftPtr ->
alloca $ \ rightPtr -> do
success <- liftM toBool $ {#call gtk_print_context_get_hard_margins #}
(toPrintContext self)
topPtr
bottomPtr
leftPtr
rightPtr
if success
then do
top <- liftM realToFrac $ peek topPtr
bottom <- liftM realToFrac $ peek bottomPtr
left <- liftM realToFrac $ peek leftPtr
right <- liftM realToFrac $ peek rightPtr
return $ Just (top, bottom, left, right)
else return Nothing
#endif
#endif
|
