ui: preserve B/V state when reloading, simplify code (#1588)

In hledger-ui TransactionScreen, set the current transaction based on RegisterScreen.

hledger-ui/Hledger/UI/RegisterScreen.hs

@@ -72,7 +72,7 @@ rsInit d reset ui@UIState{aopts=_uopts@UIOpts{cliopts_=CliOpts{reportspec_=rspec
         -- always show historical balance
       -- , balancetype_= HistoricalBalance
       }
-    rspec' = 
+    rspec' =
       either (error "rsInit: adjusting the query for register, should not have failed") id $ -- PARTIAL:
       updateReportSpec ropts' rspec
 
@@ -365,17 +365,9 @@ rsHandle ui@UIState{
         VtyEvent (EvKey (KChar 'z') [MCtrl]) -> suspend ui
 
         -- enter transaction screen for selected transaction
-        VtyEvent e | e `elem` moveRightEvents -> do
+        VtyEvent e | e `elem` moveRightEvents ->
           case listSelectedElement rsList of
-            Just (_, RegisterScreenItem{rsItemTransaction=t}) ->
-              let
-                ts = map rsItemTransaction $ V.toList $ nonblanks
-                numberedts = zip [1..] ts
-                i = maybe 0 (toInteger . (+1)) $ elemIndex t ts -- XXX
-              in
-                continue $ screenEnter d transactionScreen{tsTransaction=(i,t)
-                                                          ,tsTransactions=numberedts
-                                                          ,tsAccount=rsAccount} ui
+            Just _  -> continue $ screenEnter d transactionScreen{tsAccount=rsAccount} ui
             Nothing -> continue ui
 
         -- prevent moving down over blank padding items;

hledger-ui/Hledger/UI/TransactionScreen.hs

@@ -16,9 +16,11 @@ import Data.List
 import Data.Maybe
 import qualified Data.Text as T
 import Data.Time.Calendar (Day)
+import qualified Data.Vector as V
 import Graphics.Vty (Event(..),Key(..),Modifier(..))
+import Lens.Micro ((^.))
 import Brick
-import Brick.Widgets.List (listMoveTo)
+import Brick.Widgets.List (listElementsL, listMoveTo, listSelectedElement)
 
 import Hledger
 import Hledger.Cli hiding (progname,prognameandversion)
@@ -43,16 +45,20 @@ transactionScreen = TransactionScreen{
 tsInit :: Day -> Bool -> UIState -> UIState
 tsInit _d _reset ui@UIState{aopts=UIOpts{cliopts_=CliOpts{reportspec_=_rspec}}
                            ,ajournal=_j
-                           ,aScreen=TransactionScreen{}
+                           ,aScreen=s@TransactionScreen{tsTransaction=(_,t),tsTransactions=nts}
+                           ,aPrevScreens=prevscreens
                            } =
-  -- plog ("initialising TransactionScreen, value_ is "
-  --       -- ++ (pshow (Just (AtDefault Nothing)::Maybe ValuationType))
-  --       ++(pshow (value_ _ropts))  -- XXX calling value_ here causes plog to fail with: debug.log: openFile: resource busy (file is locked)
-  --       ++ "?"
-  --       ++" and first commodity is")
-  --       (acommodity$head$amounts$pamount$head$tpostings$snd$tsTransaction)
-  --      `seq`
-  ui
+    ui{aScreen=s{tsTransaction=(i',t'),tsTransactions=nts'}}
+  where
+    i' = maybe 0 (toInteger . (+1)) . elemIndex t' $ map snd nts'
+    -- If the previous screen was RegisterScreen, use the listed and selected items as
+    -- the transactions. Otherwise, use the provided transaction and list.
+    (t',nts') = case prevscreens of
+        RegisterScreen{rsList=xs}:_ -> (seltxn, zip [1..] $ map rsItemTransaction nonblanks)
+          where
+            seltxn = maybe nulltransaction (rsItemTransaction . snd) $ listSelectedElement xs
+            nonblanks = V.toList . V.takeWhile (not . T.null . rsItemDate) $ xs ^. listElementsL
+        _                           -> (t, nts)
 tsInit _ _ _ = error "init function called with wrong screen type, should not happen"  -- PARTIAL:
 
 tsDraw :: UIState -> [Widget Name]
@@ -129,9 +135,8 @@ tsDraw _ = error "draw function called with wrong screen type, should not happen
 tsHandle :: UIState -> BrickEvent Name AppEvent -> EventM Name (Next UIState)
 tsHandle ui@UIState{aScreen=s@TransactionScreen{tsTransaction=(i,t)
                                                ,tsTransactions=nts
-                                               ,tsAccount=acct
                                                }
-                   ,aopts=UIOpts{cliopts_=copts@CliOpts{reportspec_=rspec}}
+                   ,aopts=UIOpts{cliopts_=copts}
                    ,ajournal=j
                    ,aMode=mode
                    }
@@ -168,12 +173,7 @@ tsHandle ui@UIState{aScreen=s@TransactionScreen{tsTransaction=(i,t)
           ej <- liftIO $ journalReload copts
           case ej of
             Left err -> continue $ screenEnter d errorScreen{esError=err} ui
-            Right j' -> do
-              continue $
-                regenerateScreens j' d $
-                regenerateTransactions rspec j' s acct i $   -- added (inline) 201512 (why ?)
-                clearCostValue $
-                ui
+            Right j' -> continue $ regenerateScreens j' d ui
         VtyEvent (EvKey (KChar 'I') []) -> continue $ uiCheckBalanceAssertions d (toggleIgnoreBalanceAssertions ui)
 
         -- for toggles that may change the current/prev/next transactions,
@@ -184,12 +184,10 @@ tsHandle ui@UIState{aScreen=s@TransactionScreen{tsTransaction=(i,t)
         VtyEvent (EvKey (KChar 'B') []) ->
           continue $
           regenerateScreens j d $
-          -- regenerateTransactions ropts d j s acct i $
           toggleCost ui
         VtyEvent (EvKey (KChar 'V') []) ->
           continue $
           regenerateScreens j d $
-          -- regenerateTransactions ropts d j s acct i $
           toggleValue ui
 
         VtyEvent e | e `elem` moveUpEvents   -> continue $ regenerateScreens j d ui{aScreen=s{tsTransaction=(iprev,tprev)}}
@@ -204,29 +202,6 @@ tsHandle ui@UIState{aScreen=s@TransactionScreen{tsTransaction=(i,t)
 
 tsHandle _ _ = error "event handler called with wrong screen type, should not happen"  -- PARTIAL:
 
--- Got to redo the register screen's transactions report, to get the latest transactions list for this screen.
--- XXX Duplicates rsInit. Why do we have to do this as well as regenerateScreens ?
-regenerateTransactions :: ReportSpec -> Journal -> Screen -> AccountName -> Integer -> UIState -> UIState
-regenerateTransactions rspec j s acct i ui =
-  let
-    q = filterQuery (not . queryIsDepth) $ rsQuery rspec
-    thisacctq = Acct $ accountNameToAccountRegex acct -- includes subs
-    items = reverse $ accountTransactionsReport rspec j q thisacctq
-    ts = map first6 items
-    numberedts = zip [1..] ts
-    -- select the best current transaction from the new list
-    -- stay at the same index if possible, or if we are now past the end, select the last, otherwise select the first
-    (i',t') = case lookup i numberedts
-              of Just t'' -> (i,t'')
-                 Nothing | null numberedts -> (0,nulltransaction)
-                         | i > fst (last numberedts) -> last numberedts
-                         | otherwise -> head numberedts
-  in
-    ui{aScreen=s{tsTransaction=(i',t')
-                ,tsTransactions=numberedts
-                ,tsAccount=acct
-                }}
-
 -- | Select the nth item on the register screen.
 rsSelect i scr@RegisterScreen{..} = scr{rsList=l'}
   where l' = listMoveTo (i-1) rsList

hledger-ui/Hledger/UI/UIState.hs

@@ -105,11 +105,6 @@ toggleEmpty ui@UIState{aopts=uopts@UIOpts{cliopts_=copts@CliOpts{reportspec_=rsp
   where
     toggleEmpty ropts = ropts{empty_=not $ empty_ ropts}
 
--- | Show primary amounts, not cost or value.
-clearCostValue :: UIState -> UIState
-clearCostValue ui@UIState{aopts=uopts@UIOpts{cliopts_=copts@CliOpts{reportspec_=rspec@ReportSpec{rsOpts=ropts}}}} =
-  ui{aopts=uopts{cliopts_=copts{reportspec_=rspec{rsOpts=ropts{cost_ = NoCost, value_ = Nothing}}}}}
-
 -- | Toggle between showing the primary amounts or costs.
 toggleCost :: UIState -> UIState
 toggleCost ui@UIState{aopts=uopts@UIOpts{cliopts_=copts@CliOpts{reportspec_=rspec@ReportSpec{rsOpts=ropts}}}} =