RST reader: support scale and align attributes of images.

Closes #2662.

3 files changed, 37 insertions, 6 deletions

diff --git a/src/Text/Pandoc/Readers/RST.hs b/src/Text/Pandoc/Readers/RST.hs
index 441c573d9..f70434681 100644
--- a/src/Text/Pandoc/Readers/RST.hs
+++ b/src/Text/Pandoc/Readers/RST.hs
@@ -38,6 +38,7 @@ import Text.Pandoc.Parsing
 import Text.Pandoc.Options
 import Text.Pandoc.Logging
 import Text.Pandoc.Error
+import Text.Pandoc.ImageSize (lengthToDim, scaleDimension)
 import Control.Monad ( when, liftM, guard, mzero )
 import Data.List ( findIndex, intercalate, isInfixOf,
                    transpose, sort, deleteFirstsBy, isSuffixOf , nub, union)
@@ -624,12 +625,31 @@ directive' = do
   body <- option "" $ try $ blanklines >> indentedBlock
   optional blanklines
   let body' = body ++ "\n\n"
-      imgAttr cl = ("", classes, getAtt "width" ++ getAtt "height")
+      imgAttr cl = ("", classes, widthAttr ++ heightAttr)
         where
-          classes = words $ maybe "" trim $ lookup cl fields
-          getAtt k = case lookup k fields of
-                       Just v  -> [(k, filter (not . isSpace) v)]
-                       Nothing -> []
+          classes = words $ maybe "" trim (lookup cl fields) ++
+                      maybe "" (\x -> "align-" ++ trim x)
+                        (lookup "align" fields)
+          scale = case trim <$> lookup "scale" fields of
+                       Just v  -> case reverse v of
+                                       '%':vv ->
+                                         case safeRead (reverse vv) of
+                                              Just (percent :: Double)
+                                                      -> percent / 100.0
+                                              Nothing -> 1.0
+                                       _ ->
+                                         case safeRead v of
+                                              Just (s :: Double) -> s
+                                              Nothing -> 1.0
+                       Nothing -> 1.0
+          widthAttr = maybe [] (\x -> [("width",
+                                        show $ scaleDimension scale x)])
+                        $ lookup "width" fields >>=
+                          (lengthToDim . filter (not . isSpace))
+          heightAttr = maybe [] (\x -> [("height",
+                                         show $ scaleDimension scale x)])
+                        $ lookup "height" fields >>=
+                          (lengthToDim . filter (not . isSpace))
   case label of
         "table" -> tableDirective top fields body'
         "line-block" -> lineBlockDirective body'
diff --git a/test/command/2662.md b/test/command/2662.md
new file mode 100644
index 000000000..543209053
--- /dev/null
+++ b/test/command/2662.md
@@ -0,0 +1,11 @@
+```
+% pandoc -t html -f rst --wrap=none
+.. image:: http://url.to.image/foo.png
+   :align: left
+   :height: 100px
+   :width: 200 px
+   :scale: 300 %
+   :alt: alternate text
+^D
+<p><img src="http://url.to.image/foo.png" alt="alternate text" class="align-left" width="600" height="300" /></p>
+```
diff --git a/test/rst-reader.native b/test/rst-reader.native
index bc4641a3f..724c23b03 100644
--- a/test/rst-reader.native
+++ b/test/rst-reader.native
@@ -223,7 +223,7 @@ Pandoc (Meta {unMeta = fromList [("author",MetaList [MetaInlines [Str "John",Spa
 ,Header 1 ("images",[],[]) [Str "Images"]
 ,Para [Str "From",Space,Quoted DoubleQuote [Str "Voyage",Space,Str "dans",Space,Str "la",Space,Str "Lune"],Space,Str "by",Space,Str "Georges",Space,Str "Melies",Space,Str "(1902):"]
 ,Para [Image ("",[],[]) [Str "image"] ("lalune.jpg","")]
-,Para [Image ("",[],[("height","2343")]) [Str "Voyage dans la Lune"] ("lalune.jpg","")]
+,Para [Image ("",[],[("height","2343px")]) [Str "Voyage dans la Lune"] ("lalune.jpg","")]
 ,Para [Str "Here",Space,Str "is",Space,Str "a",Space,Str "movie",Space,Image ("",[],[]) [Str "movie"] ("movie.jpg",""),Space,Str "icon."]
 ,Para [Str "And",Space,Str "an",Space,Link ("",[],[]) [Image ("",[],[]) [Str "A movie"] ("movie.jpg","")] ("/url",""),Str "."]
 ,Header 1 ("comments",[],[]) [Str "Comments"]