Powerpoint writer: Add notesMaster to presentation.xml if necessary

In previous version, we only modified the notesMaster entry in the
presentation.xml file, and removed it if necessary. But if using a
template, it might not be available. So we always delete it, and then
add it back in if necessary.

We also have to make sure that we add it appropriately the .rels file
associated with presentation.xml.

src/Text/Pandoc/Writers/Powerpoint/Output.hs

@@ -1372,10 +1372,23 @@ getRels = do
   return $ mapMaybe elementToRel relElems
 
 presentationToRels :: PandocMonad m => Presentation -> P m [Relationship]
-presentationToRels (Presentation _ slides) = do
+presentationToRels pres@(Presentation _ slides) = do
   mySlideRels <- mapM slideToPresRel slides
+  let notesMasterRels =
+        if presHasSpeakerNotes pres
+        then [Relationship { relId = length mySlideRels + 2
+                           , relType = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/notesMaster"
+                           , relTarget = "notesMasters/notesMaster1.xml"
+                           }]
+        else []
+      insertedRels = mySlideRels ++ notesMasterRels
   rels <- getRels
-  let relsWithoutSlides = filter (\r -> relType r /= "http://schemas.openxmlformats.org/officeDocument/2006/relationships/slide") rels
+  -- we remove the slide rels and the notesmaster (if it's
+  -- there). We'll put these back in ourselves, if necessary.
+  let relsWeKeep = filter
+                   (\r -> relType r /= "http://schemas.openxmlformats.org/officeDocument/2006/relationships/slide" &&
+                          relType r /= "http://schemas.openxmlformats.org/officeDocument/2006/relationships/notesMaster")
+                   rels
   -- We want to make room for the slides in the id space. The slides
   -- will start at Id2 (since Id1 is for the slide master). There are
   -- two slides in the data file, but that might change in the future,
@@ -1384,8 +1397,9 @@ presentationToRels (Presentation _ slides) = do
   -- 1. We look to see what the minimum relWithoutSlide id (greater than 1) is.
   -- 2. We add the difference between this and the number of slides to
   -- all relWithoutSlide rels (unless they're 1)
+  -- 3. If we have a notesmaster slide, we make space for that as well.
 
-  let minRelNotOne = case filter (1<) $ map relId relsWithoutSlides of
+  let minRelNotOne = case filter (1<) $ map relId relsWeKeep of
         [] -> 0                 -- doesn't matter in this case, since
                                 -- there will be nothing to map the
                                 -- function over
@@ -1393,11 +1407,11 @@ presentationToRels (Presentation _ slides) = do
 
       modifyRelNum :: Int -> Int
       modifyRelNum 1 = 1
-      modifyRelNum n = n - minRelNotOne + 2 + length slides
+      modifyRelNum n = n - minRelNotOne + 2 + length insertedRels
 
-      relsWithoutSlides' = map (\r -> r{relId = modifyRelNum $ relId r}) relsWithoutSlides
+      relsWeKeep' = map (\r -> r{relId = modifyRelNum $ relId r}) relsWeKeep
 
-  return $ mySlideRels ++ relsWithoutSlides'
+  return $ insertedRels ++ relsWeKeep'
 
 -- We make this ourselves, in case there's a thumbnail in the one from
 -- the template.
@@ -1601,26 +1615,41 @@ presentationToPresentationElement pres@(Presentation _ slds) = do
 
       notesMasterRId = length slds + 2
 
-      modifySpeakerNotes' :: Content -> [Content]
-      modifySpeakerNotes' (Elem e) = case elName e of
-        (QName "notesMasterIdLst" _ _) ->
-          if presHasSpeakerNotes pres
-          then [Elem $
-                 mknode "p:notesMasterIdLst" []
+      notesMasterElem =  mknode "p:notesMasterIdLst" []
                          [ mknode
                            "p:NotesMasterId"
                            [("r:id", "rId" ++ show notesMasterRId)]
                            ()
                          ]
-               ]
-          else []
+
+      -- if there's a notesMasterIdLst in the presentation.xml file,
+      -- we want to remove it. We then want to put our own, if
+      -- necessary, after the slideMasterIdLst element.
+
+      removeNotesMaster' :: Content -> [Content]
+      removeNotesMaster' (Elem e) = case elName e of
+        (QName "notesMasterIdLst" _ _) -> []
         _                              -> [Elem e]
-      modifySpeakerNotes' ct = [ct]
+      removeNotesMaster' ct = [ct]
 
-      modifySpeakerNotes :: [Content] -> [Content]
-      modifySpeakerNotes = concatMap modifySpeakerNotes'
+      removeNotesMaster :: [Content] -> [Content]
+      removeNotesMaster = concatMap removeNotesMaster'
 
-      newContent = modifySpeakerNotes $ map modifySldIdLst $ elContent element
+      insertNotesMaster' :: Content -> [Content]
+      insertNotesMaster' (Elem e) = case elName e of
+        (QName "sldMasterIdLst" _ _) -> [Elem e, Elem notesMasterElem]
+        _                            -> [Elem e]
+      insertNotesMaster' ct = [ct]
+
+      insertNotesMaster :: [Content] -> [Content]
+      insertNotesMaster = if presHasSpeakerNotes pres
+                          then concatMap insertNotesMaster'
+                          else id
+
+      newContent = insertNotesMaster $
+                   removeNotesMaster $
+                   map modifySldIdLst $
+                   elContent element
 
   return $ element{elContent = newContent}