xtermjs/xterm.js

Support DECBKM to remap backspace <-> delete

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#3,041 opened on Aug 14, 2020

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 (6 comments) (0 reactions) (0 assignees)TypeScript (16,196 stars) (1,574 forks)batch import
good first issuehelp wantedtype/enhancement

Description

DECBKM to remap Backspace, Escape and Delete to their respective codes is not working at all. Quickly looking through code DECBKM is set to reset by default according to...

https://vt100.net/docs/vt510-rm/DECBKM.html

DEL issues an ESC keycode 27... which I now realise is not issuing the keycode but an ANSI sequence ESC issues keycode 27 Backspace issues keycode 127

This is troubling when you are trying to isolate what key is actually being pressed. And other odd behaviour when trying to parse things.

Code Sample

https://repl.it/@KelvinVerhey/decbkm-issue

Details

  • Chrome/Firefox/IE
  • Windows 10 Pro
  • xterm.js version: dunno... whatever repl.it is using

Question

https://stackoverflow.com/questions/63405913/xterm-js-decbkm-support-for-del-and-backspace

Contributor guide

Tech stack
typescript
Domain
frontendtooling
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
VT100 escape sequencesxterm.js codebase
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55
Research direction
Investigate the current implementation of DECBKM in the xterm.js source code, likely in the escape sequence parser (src/InputHandler.ts). Understand how the backspace and delete keys are mapped. Refer to the VT510 specification (vt100.net) for correct behavior. The issue includes a code sample that demonstrates the problem.