[Conpty] Add support for mouse input

[wez]

On: Microsoft Windows [Version 10.0.17763.134]

I have implemented conpty in my terminal emulator:
https://github.com/wez/wezterm

I can successfully run target\debug\wezterm.exe to spawn console applications such as cmd.exe powershell.exe and bash.

The issue I'm seeing is that when I launch bash, either indirectly via cmd.exe or directly via the bash launcher, conpty seems to swallow the mouse reporting escape sequences; I don't see them being received by my terminal parser, and thus vim has no effective mouse support despite being configured with set mouse=a.

Running the same WSL install via wsl-terminal does have working mouse support, and wezterm has been my daily driver on Linux for about a year with working mouse support, so we can rule out an obvious misconfiguration with vim and the parser in wezterm.

I've also tried echo -e "\e[?1000h" to manually enable mouse reporting from the shell; normally (on linux and via wsl-terminal) this causes clicks in the terminal to send data to the shell (which appears as garbage input), but when running my terminal with conpty, these are also swallowed up somewhere.

Is there something special needed for the apps that I spawn into my pty to be able to work with the mouse?

In case you want to double check the key portion of the code, the relevant file is:
https://github.com/wez/wezterm/blob/master/src/winpty.rs
The flow is to CreatePipe a pair of pipes, CreatePseudoConsole, and then pass that to a spawned child via the threadproc attributes, as the samples in the MSDN docs and this repo also do.

[DHowett-MSFT]

Hey @wez,
Unfortunately, ConPTY won't transit mouse reports (or, from a hosted application, requests for mouse reporting). We've got a backlog item tracking this that we're hoping to get to soon.

Unfortunately, we can't just pass encoded mouse events through: since ConPTY can host standard windows console applications, the likes of which would be expecting MOUSE_EVENTs to come in through ReadConsoleInput, we'll need to do some translation.

In all other regards, though, it sounds like you're setting up the pseudoconsole correctly.

---

Tracking: MSFT:20469462

[wez]

@DHowett-MSFT thanks for the response!
It's a bit of a bummer that the mouse reporting isn't there yet, but still good that the rest of the pty stuff is possible now!

[orlp]

I have nothing to add other than really wanting mouse support with ConPTY. With alacritty now having ConPTY support using alacritty + ssh + tmux is an incredible linux terminal on Windows, only mouse support is lacking now.