{- Copyright (C) 2012-2014 John MacFarlane This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -} {- | Module : Text.Pandoc.Slides Copyright : Copyright (C) 2012-2014 John MacFarlane License : GNU GPL, version 2 or above Maintainer : John MacFarlane Stability : alpha Portability : portable Utility functions for splitting documents into slides for slide show formats (dzslides, revealjs, s5, slidy, slideous, beamer). -} module Text.Pandoc.Slides ( getSlideLevel, prepSlides ) where import Text.Pandoc.Definition -- | Find level of header that starts slides (defined as the least header -- level that occurs before a non-header/non-hrule in the blocks). getSlideLevel :: [Block] -> Int getSlideLevel = go 6 where go least (Header n _ _ : x : xs) | n < least && nonHOrHR x = go n xs | otherwise = go least (x:xs) go least (_ : xs) = go least xs go least [] = least nonHOrHR (Header _ _ _) = False nonHOrHR (HorizontalRule) = False nonHOrHR _ = True -- | Prepare a block list to be passed to hierarchicalize. prepSlides :: Int -> [Block] -> [Block] prepSlides slideLevel = ensureStartWithH . splitHrule . extractRefsHeader where splitHrule (HorizontalRule : Header n attr xs : ys) | n == slideLevel = Header slideLevel attr xs : splitHrule ys splitHrule (HorizontalRule : xs) = Header slideLevel nullAttr [Str "\0"] : splitHrule xs splitHrule (x : xs) = x : splitHrule xs splitHrule [] = [] extractRefsHeader bs = case reverse bs of (Div ("",["references"],[]) (Header n attrs xs : ys) : zs) -> reverse zs ++ (Header n attrs xs : [Div ("",["references"],[]) ys]) _ -> bs ensureStartWithH bs@(Header n _ _:_) | n <= slideLevel = bs ensureStartWithH bs = Header slideLevel nullAttr [Str "\0"] : bs