a bit of refactoring

fcore/normal-mode/normal-finish.sml

@@ -0,0 +1,190 @@
+structure NormalFinish =
+struct
+  open AppType
+
+  open MailboxType
+  open DrawMsg
+  open InputMsg
+
+  fun clearMode app =
+    NormalModeWith.mode (app, NORMAL_MODE "", [])
+
+  fun buildTextAndClear
+    (app: app_type, buffer, cursorIdx, searchList, msgs, bufferModifyTime) =
+    let
+      val {windowWidth, windowHeight, startLine, searchString, ...} = app
+
+      (* move LineGap to first line displayed on screen *)
+      val buffer = LineGap.goToLine (startLine, buffer)
+
+      (* get new startLine which may move screen depending on cursor movements *)
+      val startLine = TextWindow.getStartLine
+        (buffer, startLine, cursorIdx, windowWidth, windowHeight)
+
+      (* move buffer to new startLine as required by TextBuilder.build *)
+      val buffer = LineGap.goToLine (startLine, buffer)
+
+      val msgs = TextBuilder.build
+        ( startLine
+        , cursorIdx
+        , buffer
+        , windowWidth
+        , windowHeight
+        , searchList
+        , searchString
+        , msgs
+        )
+
+      val mode = NORMAL_MODE ""
+    in
+      NormalModeWith.bufferAndCursorIdx
+        ( app
+        , buffer
+        , cursorIdx
+        , mode
+        , startLine
+        , searchList
+        , msgs
+        , bufferModifyTime
+        )
+    end
+
+  fun withSearchList (app: app_type, searchList) =
+    let
+      val {buffer, searchString, cursorIdx, bufferModifyTime, ...} = app
+      val app = NormalModeWith.searchList
+        (app, searchList, buffer, searchString, bufferModifyTime)
+    in
+      buildTextAndClear
+        (app, buffer, cursorIdx, searchList, [], bufferModifyTime)
+    end
+
+  fun resizeText (app: app_type, newWidth, newHeight) =
+    let
+      val
+        { buffer
+        , windowWidth
+        , windowHeight
+        , startLine
+        , cursorIdx
+        , searchList
+        , searchString
+        , bufferModifyTime
+        , ...
+        } = app
+
+      val newBuffer = LineGap.goToLine (startLine, buffer)
+      val lineIdx = TextBuilder.getLineAbsIdx (startLine, buffer)
+
+      val drawMsg = TextBuilder.build
+        ( startLine
+        , cursorIdx
+        , newBuffer
+        , newWidth
+        , newHeight
+        , searchList
+        , searchString
+        , []
+        )
+    in
+      NormalModeWith.bufferAndSize
+        ( app
+        , newBuffer
+        , newWidth
+        , newHeight
+        , searchList
+        , drawMsg
+        , bufferModifyTime
+        )
+    end
+
+  (* Difference between this and buildTextAndClear is that 
+   * this is meant to be called after a chr movement, 
+   * where the cursor may possibly jump off window by a wide marigin.
+   * Since the cursor may move away a lot, it is best to recenter.
+   * *)
+  fun buildTextAndClearAfterChr
+    (app: app_type, buffer, cursorIdx, searchList, initialMsg, bufferModifyTime) =
+    let
+      val {windowWidth, windowHeight, startLine, searchString, ...} = app
+
+      (* move LineGap to first line displayed on screen *)
+      val buffer = LineGap.goToLine (startLine, buffer)
+
+      (* get new startLine which may move screen depending on cursor movements *)
+      val startLine = TextWindow.getStartLine
+        (buffer, startLine, cursorIdx, windowWidth, windowHeight)
+
+      (* move buffer to new startLine as required by TextBuilder.build 
+      * and move searchList to idx where line starts as well *)
+      val buffer = LineGap.goToLine (startLine, buffer)
+
+      val drawMsg = TextBuilder.build
+        ( startLine
+        , cursorIdx
+        , buffer
+        , windowWidth
+        , windowHeight
+        , searchList
+        , searchString
+        , []
+        )
+
+      val mode = NORMAL_MODE ""
+    in
+      NormalModeWith.bufferAndCursorIdx
+        ( app
+        , buffer
+        , cursorIdx
+        , mode
+        , startLine
+        , searchList
+        , drawMsg
+        , bufferModifyTime
+        )
+    end
+
+  fun centreToCursor (app: app_type) =
+    let
+      val
+        { buffer
+        , windowWidth
+        , windowHeight
+        , startLine = origLine
+        , cursorIdx
+        , searchList
+        , searchString
+        , bufferModifyTime
+        , ...
+        } = app
+      val buffer = LineGap.goToIdx (cursorIdx, buffer)
+
+      val startLine = TextWindow.getStartLineWithCursorCentered
+        (buffer, cursorIdx, origLine, windowWidth, windowHeight div 2)
+
+      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
+end