ui: txn: up/down steps through txns in the account

doc/manual.md

@@ -2288,6 +2288,10 @@ will display the transaction in full, as a general journal entry
 This shows more detail, such as the cleared status, transaction code,
 comments and tags, and the individual account postings.
 
+You can use the cursor up/down keys to step through all transactions
+listed in the previous account register screen. Cursor left returns to
+that screen.
+
 ##### Error screen
 
 This screen will appear if there is a problem, such as a parse error,

hledger-ui/Hledger/UI/RegisterScreen.hs

@@ -209,7 +209,13 @@ handleRegisterScreen st@AppState{
 
     Vty.EvKey (k) [] | k `elem` [Vty.KRight, Vty.KEnter] -> do
       case listSelectedElement l of
-        Just (_, (_, _, _, _, _, t)) -> continue $ screenEnter d TS.screen{tsState=t} st
+        Just (_, (_, _, _, _, _, t)) ->
+          let
+            ts = map sixth6 $ V.toList $ listElements l
+            numberedts = zip [1..] ts
+            i = fromIntegral $ maybe 0 (+1) $ elemIndex t ts -- XXX
+          in
+            continue $ screenEnter d TS.screen{tsState=((i,t),numberedts,acct)} st
         Nothing -> continue st
 
     -- fall through to the list's event handler (handles [pg]up/down)

hledger-ui/Hledger/UI/TransactionScreen.hs

@@ -1,6 +1,6 @@
 -- The transaction screen, showing a single transaction's general journal entry.
 
-{-# LANGUAGE OverloadedStrings #-} -- , FlexibleContexts
+{-# LANGUAGE OverloadedStrings, TupleSections #-} -- , FlexibleContexts
 
 module Hledger.UI.TransactionScreen
  (screen
@@ -11,11 +11,13 @@ where
 import Control.Monad.IO.Class (liftIO)
 -- import Data.List
 -- import Data.List.Split (splitOn)
+-- import Data.Ord
 import Data.Monoid
 -- import Data.Maybe
 import Data.Time.Calendar (Day)
 -- import qualified Data.Vector as V
 import Graphics.Vty as Vty
+-- import Safe (headDef, lastDef)
 import Brick
 -- import Brick.Widgets.List
 -- import Brick.Widgets.Border
@@ -32,25 +34,29 @@ import Hledger.UI.UIUtils
 import qualified Hledger.UI.ErrorScreen as ES (screen)
 
 screen = TransactionScreen{
-   tsState   = nulltransaction
+   tsState   = ((1,nulltransaction),[(1,nulltransaction)],"")
   ,sInitFn   = initTransactionScreen
   ,sDrawFn   = drawTransactionScreen
   ,sHandleFn = handleTransactionScreen
   }
 
 initTransactionScreen :: Day -> AppState -> AppState
-initTransactionScreen _d st@AppState{aopts=_opts, ajournal=_j, aScreen=_s@TransactionScreen{tsState=_t}} = st
+initTransactionScreen _d st@AppState{aopts=_opts, ajournal=_j, aScreen=_s@TransactionScreen{tsState=_}} = st
 initTransactionScreen _ _ = error "init function called with wrong screen type, should not happen"
 
 drawTransactionScreen :: AppState -> [Widget]
 drawTransactionScreen AppState{ -- aopts=_uopts@UIOpts{cliopts_=_copts@CliOpts{reportopts_=_ropts@ReportOpts{query_=querystr}}},
-                               aScreen=TransactionScreen{tsState=t}} = [ui]
+                               aScreen=TransactionScreen{tsState=((i,t),nts,acct)}} = [ui]
   where
+    -- datedesc = show (tdate t) ++ " " ++ tdescription t
     toplabel =
       str "Transaction "
-      <+> withAttr ("border" <> "bold") (str $ show (tdate t) ++ " " ++ tdescription t)
+      -- <+> withAttr ("border" <> "bold") (str $ 
+      <+> withAttr ("border" <> "bold") (str $ show i)
+      <+> str (" of "++show (length nts)++" in "++acct)
     bottomlabel = borderKeysStr [
        ("left", "return to register")
+      ,("up/down", "prev/next transaction")
       ,("g", "reload")
       ,("q", "quit")
       ]
@@ -61,10 +67,14 @@ drawTransactionScreen _ = error "draw function called with wrong screen type, sh
 
 handleTransactionScreen :: AppState -> Vty.Event -> EventM (Next AppState)
 handleTransactionScreen st@AppState{
-   aScreen=_s@TransactionScreen{tsState=_t}
+   aScreen=s@TransactionScreen{tsState=((i,t),nts,acct)}
   ,aopts=UIOpts{cliopts_=_copts}
   ,ajournal=j
   } e = do
+  d <- liftIO getCurrentDay
+  let
+    (iprev,tprev) = maybe (i,t) ((i-1),) $ lookup (i-1) nts
+    (inext,tnext) = maybe (i,t) ((i+1),) $ lookup (i+1) nts
   case e of
     Vty.EvKey Vty.KEsc []        -> halt st
     Vty.EvKey (Vty.KChar 'q') [] -> halt st
@@ -76,6 +86,9 @@ handleTransactionScreen st@AppState{
         Right j' -> continue $ reload j' d st
         Left err -> continue $ screenEnter d ES.screen{esState=err} st
 
+    Vty.EvKey (Vty.KUp) []       -> continue $ reload j d st{aScreen=s{tsState=((iprev,tprev),nts,acct)}}
+    Vty.EvKey (Vty.KDown) []     -> continue $ reload j d st{aScreen=s{tsState=((inext,tnext),nts,acct)}}
+
     Vty.EvKey (Vty.KLeft) []     -> continue $ popScreen st
 
     _ev -> continue st

hledger-ui/Hledger/UI/UITypes.hs

@@ -41,7 +41,7 @@ data Screen =
     ,sDrawFn :: AppState -> [Widget]
     }
   | TransactionScreen {
-     tsState :: Transaction                                       -- ^ the transaction we are viewing
+     tsState :: ((Integer,Transaction), [(Integer,Transaction)], AccountName)         -- ^ the (numbered) transaction we are viewing, a numbered list of transactions we can step through, and the account whose register we entered this screen from
     ,sInitFn :: Day -> AppState -> AppState
     ,sHandleFn :: AppState -> V.Event -> EventM (Next AppState)
     ,sDrawFn :: AppState -> [Widget]

hledger-ui/hledger-ui.1.md

@@ -175,6 +175,10 @@ will display the transaction in full, as a general journal entry
 This shows more detail, such as the cleared status, transaction code,
 comments and tags, and the individual account postings.
 
+You can use the cursor up/down keys to step through all transactions
+listed in the previous account register screen. Cursor left returns to
+that screen.
+
 ## Error screen
 
 This screen will appear if there is a problem, such as a parse error,
@@ -201,7 +205,7 @@ The need to precede options with `--` when invoked from hledger is awkward.
 
 `-f-` doesn't work (hledger-ui can't read from stdin).
 
-`-V` doesn't affect the register screen.
+`-V` affects only the accounts screen.
 
 When you press `g`, the current and all previous screens are
 regenerated, which may cause a noticeable pause. Also there is no
@@ -210,3 +214,7 @@ visual indication that this is in progress.
 The register screen's switching between historic balance and running
 total based on query arguments may be confusing, and there is no
 column heading to indicate which is being displayed.
+
+When you navigate to an earlier or later transaction with cursor
+up/down in the transaction screen, and then return to the register
+screen, the selection will not have moved.