Add flipROflag with the key % to the keymap

This command changes the behaviour of the old 'KEnter' event as it
doesn't set ReadOnly = False when switching. This flag set/unsets with
the same command. Also documented most of the new functions on this
module.

yi-misc-modes/src/Yi/Mode/Buffers.hs

@@ -13,17 +13,19 @@
 module Yi.Mode.Buffers (listBuffers) where
 
 import           Control.Category    ((>>>))
-import           Control.Monad       (forM_, mapM_, unless, when)
+import           Control.Monad       (forM_, mapM_, unless, when
+                                     ,replicateM_)
 import           Data.Functor        (void)
-import           Lens.Micro.Platform ((.=), (%~), (.~), to, use)
+import           Lens.Micro.Platform ((.=), (%~), (.~), (%=), to, use)
 import           Data.List.NonEmpty  (NonEmpty( (:|) ))
-import qualified Data.Text           as T (intercalate, pack, append, Text)
+import qualified Data.Text           as T (intercalate, pack, append, Text
+                                          , justifyLeft)
 import           Yi.Buffer
 import           Yi.Editor
 import           Yi.Types            ( FBuffer(attributes)
                                      , Attributes(readOnly))
 import           Yi.Buffer.Misc      (isUnchangedBuffer, replaceCharB
-                                     , gotoLnFrom )
+                                     ,gotoLnFrom, rightB )
 import           Yi.Buffer.HighLevel (moveToSol, lineStreamB, topB)
 import           Yi.Buffer.Basic      (Direction(..), BufferRef(..))
 import           Yi.Keymap           (Keymap, YiM, topKeymapA)
@@ -52,7 +54,9 @@ listBuffers = do
     listBuffersName :: T.Text
     listBuffersName = "Buffer List"
 
--- | Add Emacs-like properties to the list of buffers.
+-- | Add Emacs-like properties to the list of buffers. Currently the
+--   flags .%* means that . is the current buffer, % that is read only and *
+--   that has been modified.
 bufferProperties :: NonEmpty BufferRef -> NonEmpty FBuffer -> [T.Text]
 bufferProperties (curRef :| extraRef) (curBuf :| extraBufs) =
   characterize '.' curRef curBuf
@@ -63,40 +67,54 @@ bufferProperties (curRef :| extraRef) (curBuf :| extraBufs) =
         let roChar = if readOnly attr then '%' else ' '
             modChar = if isUnchangedBuffer buf then ' ' else '*'
         in T.pack [cur, roChar, modChar, ' ']
-           `T.append` threeSpaceRef ref `T.append` " "
+           `T.append` fourSpaceRef ref `T.append` " "
            `T.append` identString buf
 
-    threeSpaceRef :: BufferRef -> T.Text
-    threeSpaceRef (BufferRef i)
-      | i < 10 = ti `T.append` "   "
-      | i >= 10 && i < 100 = ti `T.append` "  "
-      | i >= 100 && i < 1000 = ti `T.append` " "
-      | i >= 1000 && i < 10000 = ti
-      | otherwise = error "Too many buffersRefs"
-      where
-        ti = T.pack (show i)
+    fourSpaceRef :: BufferRef -> T.Text
+    fourSpaceRef (BufferRef i) = T.justifyLeft 4 ' ' (T.pack (show i))
+
+
+-- | Auxiliar function to extract the `BufferRef` from the format used in
+--   this mode
+extractBufferRef :: String -> BufferRef
+extractBufferRef l = let ref' = read $ words (drop 4 l) !! 0
+                     in  BufferRef ref'
 
 -- | Switch to the buffer with name at current name. If it it starts
 -- with a @/@ then assume it's a file and try to open it that way.
 switch :: YiM ()
 switch = do
-  s <- (drop 4 . R.toString) <$> withCurrentBuffer readLnB
-  let ref = read $ (words s) !! 0
-  withEditor $ switchToBufferE (BufferRef ref)
+  s <- R.toString <$> withCurrentBuffer readLnB
+  let ref = extractBufferRef s
+  withEditor $ switchToBufferE ref
 
--- `setFlag ' '` is basically unsetting, so we make it general.
-setFlag :: Char -> BufferM ()
-setFlag c = do
+-- | `setFlag offset char move` puts on the current line at the given
+--   `offset` from the beginning the character `char` and depending on move
+--   whether we move down a line. This is a general template for all the
+--   setting moves on the list buffer.
+setFlag :: Int -> Char -> Bool -> BufferM ()
+setFlag n c move = do
   readOnlyA .= False
-  moveToSol >> replaceCharB c
+  moveToSol >> replicateM_ n rightB >> replaceCharB c
   readOnlyA .= True
   isLast <- atLastLine
-  unless isLast (void (gotoLnFrom 1))
+  unless (isLast || not move) (void (gotoLnFrom 1))
 
 setDeleteFlag,unsetDeleteFlag :: BufferM ()
-setDeleteFlag = setFlag 'D'
-unsetDeleteFlag = setFlag ' '
+setDeleteFlag = setFlag 0 'D' True
+unsetDeleteFlag = setFlag 0 ' ' True
+
+-- | Alternate the readonly status of a buffer on the list.
+flipROFlag :: EditorM ()
+flipROFlag = do
+  s <- R.toString <$> withCurrentBuffer readLnB
+  let ref = extractBufferRef s
+      symbol = if s !! 1 == ' ' then '%' else ' '
+  withGivenBuffer ref (readOnlyA %= not)
+  withCurrentBuffer (setFlag 1 symbol False)
 
+-- | eXecute the flagged for deletion files on the list buffer. Then
+--   refresh the list.
 executeDelete :: YiM ()
 executeDelete = do
   bLines <- withCurrentBuffer (topB *> lineStreamB Forward)
@@ -117,18 +135,20 @@ executeDelete = do
 -- __v__              → open buffer as read-only
 -- __g__              → reload buffer list
 -- __d__              → flag this file for deletion
--- __g__              → delete files flagged for deletion
+-- __x__              → delete files flagged for deletion
+-- __%__              → set/unset files as read-only
 -- @
 bufferKeymap :: Keymap -> Keymap
 bufferKeymap = important $ choice
   [ char 'p'                        ?>>! lineUp
   , oneOf [ char 'n', char ' ' ]    >>! lineDown
-  , oneOf [ spec KEnter, char 'f' ] >>! (switch >> setReadOnly False)
+  , oneOf [ spec KEnter, char 'f' ] >>! switch
   , char 'v'                        ?>>! (switch >> setReadOnly True)
   , char 'g'                        ?>>! listBuffers
   , char 'd'                        ?>>! setDeleteFlag
   , char 'x'                        ?>>! executeDelete
   , char 'u'                        ?>>! unsetDeleteFlag
+  , char '%'                        ?>>! flipROFlag
   ]
   where
     setReadOnly = withCurrentBuffer . (.=) readOnlyA