-- return if cursor is not visible on screen
    if pane.cursor_x < 0 or pane.cursor_x >= App.screen.width then
      return
    end
    if pane.cursor_y < Header_height or pane.cursor_y >= App.screen.height then
      return
    end
    if chord == 'C-e' then
      command.exit_editing()
    else
--?       print(('%s pressed in editor pane'):format(chord))
      local old_top = {line=pane.screen_top1.line, pos=pane.screen_top1.pos}
      edit.keychord_pressed(pane, chord, key)
--?       print('screen top after:', pane.screen_top1.line, pane.screen_top1.pos)
      Editable_cursor_pane_updated_screen_top = not eq(old_top, pane.screen_top1)
      if Editable_cursor_pane_updated_screen_top then
--?         print('updating viewport based on screen top')
        Display_settings.y = up_edge_sy(Cursor_pane.col, Cursor_pane.row) + y_of_schema1(pane, pane.screen_top1)
--?         print(('display settings.y is now %d'):format(Display_settings.y))
        Surface.cursor_on_screen_check = true  -- cursor was on screen before keystroke, so it should remain on screen after
      end
      update_metadata(pane)
    end

    keychord_pressed_on_editable_pane(pane, chord, key)

    -- return if no part of cursor pane is visible
    local left_sx = left_edge_sx(Cursor_pane.col)
    if not overlap(left_sx, left_sx+Display_settings.column_width, Display_settings.x, Display_settings.x+App.screen.width) then
      return
    end
    local up_sy = up_edge_sy(Cursor_pane.col, Cursor_pane.row)
    if not overlap(up_sy, up_sy+pane.height, Display_settings.y, Display_settings.y+App.screen.height-Header_height) then
      return
    end
    if chord == 'C-e' then
      command.edit_note_at_cursor()
    else
      keychord_pressed_on_immutable_pane(pane, chord, key)
    end

    keychord_pressed_in_normal_mode_with_immutable_pane(pane, chord, key)

end
function keychord_pressed_on_editable_pane(pane, chord, key)
  -- ignore if cursor is not visible on screen
  if pane.cursor_x < 0 or pane.cursor_x >= App.screen.width then
    return
  end
  if pane.cursor_y < Header_height or pane.cursor_y >= App.screen.height then
    return
  end
  if chord == 'C-e' then
    command.exit_editing()
  else
--?     print(('%s pressed in editor pane'):format(chord))
    local old_top = {line=pane.screen_top1.line, pos=pane.screen_top1.pos}
    edit.keychord_pressed(pane, chord, key)
--?     print('screen top after:', pane.screen_top1.line, pane.screen_top1.pos)
    Editable_cursor_pane_updated_screen_top = not eq(old_top, pane.screen_top1)
    if Editable_cursor_pane_updated_screen_top then
--?       print('updating viewport based on screen top')
      Display_settings.y = up_edge_sy(Cursor_pane.col, Cursor_pane.row) + y_of_schema1(pane, pane.screen_top1)
--?       print(('display settings.y is now %d'):format(Display_settings.y))
      Surface.cursor_on_screen_check = true  -- cursor was on screen before keystroke, so it should remain on screen after
    end
    update_metadata(pane)
  end
end
function keychord_pressed_in_normal_mode_with_immutable_pane(pane, chord, key)
  -- return if no part of cursor pane is visible
  local left_sx = left_edge_sx(Cursor_pane.col)
  if not overlap(left_sx, left_sx+Display_settings.column_width, Display_settings.x, Display_settings.x+App.screen.width) then
    return
  end
  local up_sy = up_edge_sy(Cursor_pane.col, Cursor_pane.row)
  if not overlap(up_sy, up_sy+pane.height, Display_settings.y, Display_settings.y+App.screen.height-Header_height) then
    return
  end
  if chord == 'C-e' then
    command.edit_note_at_cursor()
  else
    keychord_pressed_on_immutable_pane(pane, chord, key)
  end