assert(State.lines[State.cursor1.line].mode == 'text')

  return loc1.line > #State.lines
      or loc1.pos > #State.lines[loc1.line].data

  if loc1.line > #State.lines then return true end
  local l = State.lines[loc1.line]
  if l.mode ~= 'text' then return false end  -- pos is irrelevant to validity for a drawing line
  return loc1.pos > #State.lines[loc1.line].data

        button(State, 'draw', {x=4,y=y+4, w=12,h=12, color={1,1,0},

        button(State, 'draw', {x=State.left-Margin_left+4, y=y+4, w=12,h=12, color={1,1,0},

--?   print('press', State.selection1.line, State.selection1.pos)

--?   print('press', State.cursor1.line)

--?   print('release')

--?   print('release', State.cursor1.line)

--?   print('text input', t)

  elseif State.current_drawing_mode == 'name' then

  elseif State.lines.current_drawing and State.current_drawing_mode == 'name' then

  elseif State.current_drawing_mode == 'name' then

  elseif State.lines.current_drawing and State.current_drawing_mode == 'name' then

        local byte_offset = Text.offset(p.name, len-1)
        if len == 1 then byte_offset = 0 end
        p.name = string.sub(p.name, 1, byte_offset)
        record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})

        if len > 0 then
          local byte_offset = Text.offset(p.name, len-1)
          if len == 1 then byte_offset = 0 end
          p.name = string.sub(p.name, 1, byte_offset)
          record_undo_event(State, {before=before, after=snapshot(State, State.lines.current_drawing_index)})
        end