Slidy writer: create new slide at every level 1 header.

README

@@ -1349,11 +1349,9 @@ directory.
 Using Slidy
 -----------
 
-If you use Slidy, things work a bit differently.  Instead of
-automatically chopping the document into sections on the level-1
-headers, you can choose how to segment the document into slides
-yourself. Just insert a horizontal rule at each slide boundary.
-For example:
+If you use Slidy, things work a bit differently. As with S5, a new slide
+will be created at every level 1 header.  But you can also force a new
+slide by inserting a horizontal rule. For example:
 
     % Eating Habits
     % John Doe

src/Text/Pandoc/Writers/HTML.hs

@@ -105,8 +105,11 @@ pandocToHtml opts (Pandoc (Meta title' authors' date') blocks) = do
   toc <- if writerTableOfContents opts 
             then tableOfContents opts sects
             else return Nothing
-  let cutUp (HorizontalRule : xs) = RawHtml "</div>\n<div class=\"slide\">\n" :
+  let cutUp (HorizontalRule : Header 1 ys : xs) = cutUp (Header 1 ys : xs)
+      cutUp (HorizontalRule : xs) = RawHtml "</div>\n<div class=\"slide\">\n" :
                                     cutUp xs
+      cutUp (Header 1 ys : xs)    = RawHtml ("</div>\n<div class=\"slide title\">\n") :
+                                    Header 1 ys : cutUp xs
       cutUp (x:xs)                = x : cutUp xs
       cutUp []                    = [] 
   blocks' <- liftM toHtmlFromList $