Module screen 

Screen, line, scroll-region, and tab-stop manipulation.

Category

This module emits CSI controls for erasing, inserting/deleting characters and lines, scrolling, setting vertical and horizontal margins, and tab-stop management.

CSI conventions

Counted operations use the terminal default parameter where possible: for example n <= 1 emits ESC [ X for ECH and ESC [ L for IL. Erase operations use parameter 0 as the omitted default.

Mode interaction

Left/right margins are interpreted as DECSLRM when Mode::LEFT_RIGHT_MARGIN is enabled. Top/bottom scroll margins are set by DECSTBM and affect absolute cursor movement when origin mode is active.

Constants

ERASE_ENTIRE_DISPLAY

Erase the display including scrollback where supported: exact bytes ESC [ 3 J (ED 3).

ERASE_ENTIRE_LINE

Erase the entire current line: exact bytes ESC [ 2 K (EL 2).

ERASE_ENTIRE_SCREEN

Erase the visible screen: exact bytes ESC [ 2 J (ED 2).

ERASE_LINE_LEFT

Erase from start of line through cursor: exact bytes ESC [ 1 K (EL 1).

ERASE_LINE_RIGHT

Erase from cursor through end of line: exact bytes ESC [ K (EL 0).

ERASE_SCREEN_ABOVE

Erase from start of screen through cursor: exact bytes ESC [ 1 J (ED 1).

ERASE_SCREEN_BELOW

Erase from cursor through end of screen: exact bytes ESC [ J (ED 0).

HORIZONTAL_TAB_SET

Set a horizontal tab stop at the current column: exact bytes ESC H (HTS 7-bit form).

SET_TAB_EVERY_8_COLUMNS

Set tab stops every eight columns: exact bytes ESC [ ? 5 W (DECST8C).

Functions

write_dch

Delete n character cells at the cursor with DCH.

write_delete_lines

Delete n lines with DL.

write_ech

Erase n character cells at the cursor with ECH.

write_ed

Erase in display with ED, ESC [ <n> J.

write_el

Erase in line with EL, ESC [ <n> K.

write_erase_below

Write ERASE_SCREEN_BELOW, ESC [ J, erasing from cursor through end of screen.

write_erase_line

Write ERASE_ENTIRE_LINE, ESC [ 2 K, erasing the entire current line.

write_erase_screen

Write ERASE_ENTIRE_SCREEN, ESC [ 2 J, erasing the visible screen.

write_erase_to_eol

Write ERASE_LINE_RIGHT, ESC [ K, erasing from cursor through end of line.

write_hts

Write HORIZONTAL_TAB_SET, ESC H, to set a tab stop at the current cursor column.

write_ich

Insert n blank character cells at the cursor with ICH.

write_insert_lines

Insert n blank lines with IL.

write_rep

Repeat the preceding printable character with REP.

write_reset_scroll_region

Reset top/bottom margins to the full screen with exact bytes ESC [ r.

write_reset_tab_stops_every_8

Reset tab stops to one every eight columns without DECST8C.

write_scroll_down

Scroll down by n lines with SD.

write_scroll_region

Set top and bottom margins with DECSTBM, ESC [ <top+1> ; <bottom+1> r.

write_scroll_up

Scroll up by n lines with SU.

write_set_left_right_margins

Set left and right margins with DECSLRM, ESC [ <left> ; <right> s.

write_tbc

Clear tab stops with TBC, ESC [ <n> g.