Allow wrapping at a specific column

README.md

@@ -301,7 +301,8 @@ are several places where you can put your configuration.
 ### Line wrapping
 
 Line wrapping can be enabled by setting `wrap: true` in the configuration.  This
-will re-wrap all lines to fit the terminal width better.
+will re-wrap all lines to fit the terminal width better.  You can also ask patat
+to wrap at a specific column using e.g. `wrap: 60`.
 
 ### Margins
 
@@ -352,8 +353,8 @@ patat:
 Hello world
 ```
 
-Setting `wrap: true` is recommended when vertically centering content if there
-are any lines that are too wide for the terminal.
+[Line wrapping](#line-wrapping) is recommended when vertically centering content
+if there are any lines that are too wide for the terminal.
 
 ### Auto advancing
 

lib/Patat/Presentation/Display.hs

@@ -60,7 +60,7 @@ displayWithBorders (Size rows columns) pres@Presentation {..} f =
     settings  = activeSettings pres
     ds        = DisplaySettings
         { dsSize          = canvasSize
-        , dsWrap          = fromMaybe False $ psWrap settings
+        , dsWrap          = fromMaybe NoWrap $ psWrap settings
         , dsMargins       = margins settings
         , dsTheme         = fromMaybe Theme.defaultTheme (psTheme settings)
         , dsSyntaxMap     = pSyntaxMap
@@ -204,9 +204,10 @@ prettyFragment ds (Fragment blocks) = vertical $
                 Auto      -> (columns - dcols) `div` 2
         indentation = PP.Indentation left mempty
 
-    horizontalWrap doc0
-        | dsWrap ds = PP.wrapAt (Just $ columns - right - left) doc0
-        | otherwise = doc0
+    horizontalWrap doc0 = case dsWrap ds of
+        NoWrap     -> doc0
+        AutoWrap   -> PP.wrapAt (Just $ columns - right - left) doc0
+        WrapAt col -> PP.wrapAt (Just col) doc0
       where
         right = case mRight of
             Auto      -> 0

lib/Patat/Presentation/Display/Internal.hs

@@ -7,6 +7,7 @@ module Patat.Presentation.Display.Internal
 
 --------------------------------------------------------------------------------
 import           Patat.Presentation.Internal (Margins)
+import           Patat.Presentation.Settings (Wrap)
 import qualified Patat.PrettyPrint           as PP
 import           Patat.Size                  (Size)
 import qualified Patat.Theme                 as Theme
@@ -16,7 +17,7 @@ import qualified Skylighting                 as Skylighting
 --------------------------------------------------------------------------------
 data DisplaySettings = DisplaySettings
     { dsSize      :: !Size
-    , dsWrap      :: !Bool
+    , dsWrap      :: !Wrap
     , dsMargins   :: !Margins
     , dsTheme     :: !Theme.Theme
     , dsSyntaxMap :: !Skylighting.SyntaxMap

lib/Patat/Presentation/Settings.hs

@@ -6,6 +6,7 @@ module Patat.Presentation.Settings
     ( PresentationSettings (..)
     , defaultPresentationSettings
 
+    , Wrap (..)
     , AutoOr (..)
     , MarginSettings (..)
 
@@ -25,6 +26,7 @@ module Patat.Presentation.Settings
 
 
 --------------------------------------------------------------------------------
+import           Control.Applicative    ((<|>))
 import           Control.Monad          (mplus)
 import qualified Data.Aeson.Extended    as A
 import qualified Data.Aeson.TH.Extended as A
@@ -46,7 +48,7 @@ data PresentationSettings = PresentationSettings
     { psRows              :: !(Maybe (A.FlexibleNum Int))
     , psColumns           :: !(Maybe (A.FlexibleNum Int))
     , psMargins           :: !(Maybe MarginSettings)
-    , psWrap              :: !(Maybe Bool)
+    , psWrap              :: !(Maybe Wrap)
     , psTheme             :: !(Maybe Theme.Theme)
     , psIncrementalLists  :: !(Maybe Bool)
     , psAutoAdvanceDelay  :: !(Maybe (A.FlexibleNum Int))
@@ -101,6 +103,17 @@ defaultPresentationSettings = mempty
     }
 
 
+--------------------------------------------------------------------------------
+data Wrap = NoWrap | AutoWrap | WrapAt Int deriving (Show)
+
+
+--------------------------------------------------------------------------------
+instance A.FromJSON Wrap where
+    parseJSON val =
+        ((\w -> if w then AutoWrap else NoWrap) <$> A.parseJSON val) <|>
+        (WrapAt <$> A.parseJSON val)
+
+
 --------------------------------------------------------------------------------
 data AutoOr a = Auto | NotAuto a deriving (Show)
 

tests/golden/inputs/wrap-at.md

@@ -0,0 +1,35 @@
+<!--config:
+  wrap: 40
+-->
+
+This is a really long sentence which could be wrapped.
+
+- The above sentence should be wrapped.
+- This bullet list should also be wrapped.
+
+---
+
+<!--config:
+  wrap: 40
+  margins:
+    left: auto
+    right: auto
+-->
+
+This is a really long sentence which could be wrapped.
+
+- The above sentence should be wrapped.
+- This bullet list should also be wrapped.
+
+---
+
+<!--config:
+  wrap: 40
+  margins:
+    left: 10
+-->
+
+This is a really long sentence which could be wrapped.
+
+- The above sentence should be wrapped.
+- This bullet list should also be wrapped.

tests/golden/outputs/wrap-at.md.dump

@@ -0,0 +1,37 @@
+                               wrap-at.md                               
+
+This is a really long sentence which
+could be wrapped.
+
+  - The above sentence should be
+    wrapped.
+  - This bullet list should also be
+    wrapped.
+
+                                                                  1 / 3 
+
+{slide}
+                               wrap-at.md                               
+
+                  This is a really long sentence which
+                  could be wrapped.
+
+                    - The above sentence should be
+                      wrapped.
+                    - This bullet list should also be
+                      wrapped.
+
+                                                                  2 / 3 
+
+{slide}
+                               wrap-at.md                               
+
+          This is a really long sentence which
+          could be wrapped.
+
+            - The above sentence should be
+              wrapped.
+            - This bullet list should also be
+              wrapped.
+
+                                                                  3 / 3