Support title from xterm.js

[Tyriar]

From @pharmmd-rich in #22319

The dropdown list currently displays a list of processes, however, I like giving my terminals custom names in OS-X. The drop down list does not appear to honor these names. (they are set using: printf '\033]0;title\007'".

Open to PRs, we will want to handle xterm.on('title', listener) inside TerminalInstance and use that over the pty name if it's set. Currently I'm assuming this will only fire if the user has set up a title they want to use, whether of not the event is guarenteed to fire on new terminals might change my thinking on how it works.

[Tyriar]

@Lixire here's one of the PRs with some extra detail in what needs to happen #22454 (comment)

[Tyriar]

Just added a new setting for this, set:

"terminal.integrated.experimentalUseTitleEvent": true

To use the title from the VT sequence.

[dee-kryvenko]

@Tyriar thanks a lot! I just tried it, and it seems that it works, with a little issue though.
So I usually right click on a sub-folder and choose Open in Terminal. When I do that with experimentalUseTitleEvent enabled, the title automatically set to 1: /bin/bash. But if I cd . it will properly update the title after changing the directory.

Version: 1.38.0-insider
Commit: 0f73473c08055054f317c1c94502f7f39fdbb164
Date: 2019-08-23T05:36:33.571Z
Electron: 4.2.9
Chrome: 69.0.3497.128
Node.js: 10.11.0
V8: 6.9.427.31-electron.0
OS: Darwin x64 18.7.0

UPD: I just tried it on 1.38.0, same behavior is reproducible there.

[Tyriar]

Sounds like the first event isn't getting fired, should get fixed before we remove experimental.

[cr4ckm3]

Also it shows whole path with user@userdomain, would be perfect if I can choose to show only last folder name or set in workspace config the name of the terminal. Thanks a lot!

[dee-kryvenko]

I've been using vscode on Mac OS Mojave with bash and it seems to be working as @cr4ckm3 described (dropdown name is an equivalent of basename $(pwd)). I just upgraded to Catalina where they made zsh a default shell and I decided to give it a shot. With zsh it uses ${whoami}@${hostname} $(print -rD $PWD), which is too long and the only visible part is username+hostname so I couldn't tell which terminal I'm looking at right away without clicking on dropdown to see expanded list.

[Tyriar]

The setting is now titleMode in the upcoming Insiders release