Add missing clearAfter to listview

listview.lua

@@ -1,4 +1,5 @@
 local backingList = {}
+local length = 0
 local paginationOffset = 1
 local frame = term.current()
 local drawLine = nil
@@ -27,9 +28,24 @@ end
 
 local function updateItemAt(idx, item)
     backingList[idx] = item
+    if idx > length then
+        length = idx
+    end
     redrawLine(idx)
 end
 
+local function clearAfter(idx)
+    local tw, th = frame.getSize()
+    for j = length, idx+1, -1 do
+        backingList[j] = nil
+    end
+    length = idx
+    for y = paginationOffset-idx+2, th, 1 do
+        frame.setCursorPos(1, y)
+        frame.clearLine()
+    end
+end
+
 local function redraw()
     if drawLine then
         local tw, th = frame.getSize()
@@ -56,6 +72,7 @@ return {
     setDrawLineFunc=setDrawLineFunc,
     itemAt=itemAt,
     updateItemAt=updateItemAt,
+    clearAfter=clearAfter,
     redraw=redraw,
     updatePage=updatePage,
 }