--?     print(Screen_top1.line, Screen_top1.pos, Cursor1.line, Cursor1.pos, Screen_bottom1.line, Screen_bottom1.pos)

        if (Cursor_y + Line_height) > App.screen.height then
          Text.snap_cursor_to_bottom_of_screen()
        end

--?         print(Screen_top1.line, Screen_top1.pos, Cursor1.line, Cursor1.pos, Screen_bottom1.line, Screen_bottom1.pos)

        if Cursor_y >= App.screen.height - Line_height then
          Text.populate_screen_line_starting_pos(Cursor1.line)
          Text.snap_cursor_to_bottom_of_screen()
--?           print('=>', Screen_top1.line, Screen_top1.pos, Cursor1.line, Cursor1.pos, Screen_bottom1.line, Screen_bottom1.pos)
        end

    end
    App.draw()
    if Cursor_y >= App.screen.height - Line_height then
      Text.populate_screen_line_starting_pos(Cursor1.line)
      Text.snap_cursor_to_bottom_of_screen()
--?       print('=>', Screen_top1.line, Screen_top1.pos, Cursor1.line, Cursor1.pos, Screen_bottom1.line, Screen_bottom1.pos)

* Large files may grow sluggish in other ways. Pasting more than a line or two
  gets slow. I've noticed in 100KB files that closing the window can take a
  few seconds. And it seems to take longer in proportion to how far down my
  edits are. The phenomenon persists even if I take out undo history.

* Large files may grow sluggish in other ways. I've noticed in 100KB files
  that closing the window can take a few seconds. And it seems to take longer
  in proportion to how far down my edits are. The phenomenon persists even if
  I take out undo history.