refactor to make sure that we count the visual scroll column on move/delete, in normal mode

fcore/normal-mode/make-normal-delete.sml

@@ -400,6 +400,7 @@ struct
 
       val cursorIdx = 0
       val startLine = 0
+      val visualScrollColumn = 0
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
 
       val drawMsg = TextBuilder.build
@@ -416,7 +417,16 @@ struct
       val mode = NORMAL_MODE ""
     in
       NormalModeWith.bufferAndCursorIdx
-        (app, buffer, cursorIdx, mode, startLine, searchList, drawMsg, time)
+        ( app
+        , buffer
+        , cursorIdx
+        , mode
+        , startLine
+        , searchList
+        , drawMsg
+        , time
+        , visualScrollColumn
+        )
     end
 
   fun helpDeleteToMatch (app: app_type, low, high, time) =

fcore/normal-mode/normal-finish.sml

@@ -16,7 +16,8 @@ struct
 
       (* calculate scroll column *)
       val buffer = LineGap.goToIdx (cursorIdx, buffer)
-      val visualScrollColumn = TextScroll.getScrollColumn (buffer, cursorIdx, windowWidth)
+      val visualScrollColumn =
+        TextScroll.getScrollColumn (buffer, cursorIdx, windowWidth)
 
       (* move LineGap to first line displayed on screen *)
       val buffer = LineGap.goToLine (startLine, buffer)
@@ -50,6 +51,7 @@ struct
         , searchList
         , msgs
         , bufferModifyTime
+        , visualScrollColumn
         )
     end
 
@@ -84,7 +86,10 @@ struct
         , ...
         } = app
 
-      val newBuffer = LineGap.goToLine (startLine, buffer)
+      val newBuffer = LineGap.goToIdx (cursorIdx, buffer)
+      val visualScrollColumn =
+        TextScroll.getScrollColumn (buffer, cursorIdx, windowWidth)
+      val newBuffer = LineGap.goToLine (startLine, newBuffer)
       val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
 
       val drawMsg = TextBuilder.build
@@ -106,6 +111,7 @@ struct
         , searchList
         , drawMsg
         , bufferModifyTime
+        , visualScrollColumn
         )
     end
 
@@ -119,6 +125,10 @@ struct
     let
       val {windowWidth, windowHeight, startLine, searchString, ...} = app
 
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+      val visualScrollColumn =
+        TextScroll.getScrollColumn (buffer, cursorIdx, windowWidth)
+
       (* move LineGap to first line displayed on screen *)
       val buffer = LineGap.goToLine (startLine, buffer)
 
@@ -152,6 +162,7 @@ struct
         , searchList
         , drawMsg
         , bufferModifyTime
+        , visualScrollColumn
         )
     end
 
@@ -187,15 +198,20 @@ struct
         , []
         )
     in
-      NormalModeWith.bufferAndCursorIdx
-        ( app
-        , buffer
-        , cursorIdx
-        , NORMAL_MODE ""
-        , startLine
-        , searchList
-        , drawMsg
-        , bufferModifyTime
-        )
+      let
+        val _ = raise Fail "centering to line is unimplemented\n"
+      in
+        NormalModeWith.bufferAndCursorIdx
+          ( app
+          , buffer
+          , cursorIdx
+          , NORMAL_MODE ""
+          , startLine
+          , searchList
+          , drawMsg
+          , bufferModifyTime
+          , #visualScrollColumn app
+          )
+      end
     end
 end

fcore/normal-mode/normal-mode-with.sml

@@ -10,6 +10,7 @@ struct
     , newSearchList
     , newMsgs
     , newBufferModifyTime
+    , newVisualScrollColumn
     ) =
     let
       val
@@ -19,11 +20,11 @@ struct
         , windowWidth = _
         , windowHeight = _
         , searchList = _
+        , visualScrollColumn = _
         , msgs = _
         , searchString
         , startLine
         , cursorIdx
-        , visualScrollColumn
         } = app
     in
       { mode = mode
@@ -32,11 +33,11 @@ struct
       , windowWidth = newWidth
       , windowHeight = newHeight
       , searchList = newSearchList
+      , visualScrollColumn = newVisualScrollColumn
       , msgs = newMsgs
       , searchString = searchString
       , startLine = startLine
       , cursorIdx = cursorIdx
-      , visualScrollColumn = visualScrollColumn
       }
     end
 
@@ -49,6 +50,7 @@ struct
     , newSearchList
     , newMsgs
     , newBufferModifyTime
+    , newVisualScrollColumn
     ) =
     let
       val
@@ -58,11 +60,11 @@ struct
         , cursorIdx = _
         , startLine = _
         , searchList = _
+        , visualScrollColumn = _
         , msgs = _
         , searchString
         , windowWidth
         , windowHeight
-        , visualScrollColumn
         } = app
     in
       { mode = newMode
@@ -71,11 +73,11 @@ struct
       , cursorIdx = newCursorIdx
       , startLine = newStartLine
       , searchList = newSearchList
+      , visualScrollColumn = newVisualScrollColumn
       , msgs = newMsgs
       , searchString = searchString
       , windowWidth = windowWidth
       , windowHeight = windowHeight
-      , visualScrollColumn = visualScrollColumn
       }
     end
 

fcore/normal-mode/normal-move.sml

@@ -40,6 +40,7 @@ struct
         , searchList
         , drawMsg
         , bufferModifyTime
+        , 0
         )
     end
 
@@ -63,6 +64,8 @@ struct
       val bufferLine = bufferLine - 1
 
       val buffer = LineGap.goToIdx (bufferIdx, buffer)
+      val visualScrollColumn =
+        TextScroll.getScrollColumn (buffer, bufferIdx, windowWidth)
       val bufferLine =
         let
           val maxHeight = windowHeight - TextConstants.ySpace
@@ -96,6 +99,7 @@ struct
         , searchList
         , drawMsg
         , bufferModifyTime
+        , visualScrollColumn
         )
     end
 
@@ -120,6 +124,8 @@ struct
         val cursorIdx = Cursor.getLineStartIdx (buffer, reqLine)
 
         val buffer = LineGap.goToIdx (cursorIdx, buffer)
+        val visualScrollColumn =
+          TextScroll.getScrollColumn (buffer, cursorIdx, windowWidth)
         val startLine = TextWindow.getStartLineWithCursorCentered
           (buffer, cursorIdx, origLine, windowWidth, windowHeight div 2)
 
@@ -148,6 +154,7 @@ struct
           , searchList
           , drawMsg
           , bufferModifyTime
+          , visualScrollColumn
           )
       end
 
@@ -172,66 +179,39 @@ struct
       val buffer = LineGap.goToLine (startLine, buffer)
       val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
     in
-      if
-        TextWindow.isCursorVisible
-          (buffer, cursorIdx, startLine, windowWidth, windowHeight)
-      then
-        (* if visible, just need to redraw; no need to get line *)
-        let
-          val drawMsg = TextBuilder.build
-            ( startLine
-            , cursorIdx
-            , buffer
-            , windowWidth
-            , windowHeight
-            , searchList
-            , searchString
-            , []
-            )
-        in
-          NormalModeWith.bufferAndCursorIdx
-            ( app
-            , buffer
-            , cursorIdx
-            , NORMAL_MODE ""
-            , startLine
-            , searchList
-            , drawMsg
-            , bufferModifyTime
-            )
-        end
-      else
-        (* not visible, so need to get startLine where cursor is visible *)
-        let
-          val buffer = LineGap.goToIdx (cursorIdx, buffer)
-          val startLine = TextWindow.getStartLineWithCursorCentered
-            (buffer, cursorIdx, startLine, windowWidth, windowHeight div 2)
+      let
+        val buffer = LineGap.goToIdx (cursorIdx, buffer)
+        val visualScrollColumn =
+          TextScroll.getScrollColumn (buffer, cursorIdx, windowWidth)
+        val startLine = TextWindow.getStartLineWithCursorCentered
+          (buffer, cursorIdx, startLine, windowWidth, windowHeight div 2)
 
-          val buffer = LineGap.goToLine (startLine, buffer)
-          val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+        val buffer = LineGap.goToLine (startLine, buffer)
+        val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
 
-          val drawMsg = TextBuilder.build
-            ( startLine
-            , cursorIdx
-            , buffer
-            , windowWidth
-            , windowHeight
-            , searchList
-            , searchString
-            , []
-            )
-        in
-          NormalModeWith.bufferAndCursorIdx
-            ( app
-            , buffer
-            , cursorIdx
-            , NORMAL_MODE ""
-            , startLine
-            , searchList
-            , drawMsg
-            , bufferModifyTime
-            )
-        end
+        val drawMsg = TextBuilder.build
+          ( startLine
+          , cursorIdx
+          , buffer
+          , windowWidth
+          , windowHeight
+          , searchList
+          , searchString
+          , []
+          )
+      in
+        NormalModeWith.bufferAndCursorIdx
+          ( app
+          , buffer
+          , cursorIdx
+          , NORMAL_MODE ""
+          , startLine
+          , searchList
+          , drawMsg
+          , bufferModifyTime
+          , visualScrollColumn
+          )
+      end
     end
 
   fun firstNonSpaceChr (app: app_type) =