catch resize events on windows

[dankamongmen]

I assume Windows doesn't make use of POSIX signals (probably a good thing), so we'll need some replacement for SIGWINCH handling on that platform. @michaelsbradleyjr in #1953 refers to some event. thirty seconds of search suggests that the emulator receives a WM_SIZING message through its WindowProc function, which @michaelsbradleyjr 's mention of PeekConsoleInputW kinda implies gets turned into an input on stdin (maybe not)?

[michaelsbradleyjr]

At one point I was researching terminal resize on Windows given the lack of SIGWINCH and found this:

nico-abram/kibi@434b355

This is the part that caught my eye:

pub fn has_window_size_changed() -> bool { 
    let mut buf: [INPUT_RECORD; 1024] = [Default::default(); 1024];
    let mut read: u32 = 0;
    unsafe {
        PeekConsoleInputW(
            std::os::windows::io::AsRawHandle::as_raw_handle(&HandleRef::stdin()), 
            buf.as_mut_ptr(), 1024, &mut read)
    };
    return buf.iter().any(|x| x.EventType == WINDOW_BUFFER_SIZE_EVENT);
}

I don't recall exactly which search terms, GitHub issues/PRs, etc. I used/followed to end up there, but I kept a note of the commit for future reference.

[michaelsbradleyjr]

Actually, nevermind, it doesn't work... I found the relevant GH issue (a PR was never made):

ilai-deutel/kibi#32 (comment)

[dankamongmen]

this obviously ties into #1982

[WSLUser]

https://docs.microsoft.com/en-us/windows/console/ Perhaps this will help. Specifically:

Finding the window size must still be performed with GetConsoleScreenBufferInfo for applications attempting to draw columns, grids, or fill the display. Window and buffer size will match in a pseudoconsole session.

[dankamongmen]

According to the esteemed @magiblot, it looks like we get window resize events with ReadConsoleInputW. we can put that together with GetConsoleScreenBufferInfo as mentioned by @WSLUser above, and that ought be a complete solution.

[dankamongmen]

we've got the GetConsoleScreenBufferInfo() working now (though only for Windows Terminal, not for mintty). we need switch from read() to ReadConsoleInputW() in src/lib/input.c.