Add support for CSI 18t

[michalnpl]

Adds support for CSI 18t to report the buffer screen size in characters.

This pull request adds support for CSI 18t. When submitted to the terminal, it will respond with "\033[8;{A};{B}t" where A is equal to the height and B is equal to the width of the screen buffer in the number of characters (not pixels).

Validation Steps Performed

Manual tests against PowerShell 7 and ConHost.
Added adapterTest

Closes #13944

[michalnpl]

There are no TAEF tests. If you can add tests to this PR, I would greatly appreciate it so I can learn.

[zadjii-msft]

FWIW, I think we'll be swamped getting 1.18 out the door, so reviews might be slow.

You might be able to do something like

void ScreenBufferTests::TestGetWindowSizeInVt()
{
    auto& gci = ServiceLocator::LocateGlobals().getConsoleInformation();
    auto& si = gci.GetActiveOutputBuffer();
    auto& stateMachine = si.GetStateMachine();
    auto& cursor = si.GetTextBuffer().GetCursor();

    stateMachine.ProcessString(L"\x1b[18t");
    
    
    gci.pInputBuffer.Read(...);

and then check the Char of each of those key events.

Sorry I'm not more help ATM. Maybe after we sign off on 1.18 I can help more. We apparently didn't have tests like this, so I don't blame you for not writing a test for this one. I don't think there is prior art

[zadjii-msft]

I'm tempted to say that this is okay, but IIRC @j4james thought we should use the buffer width, not just the viewport width here.

[michalnpl]

Adressed.

[michalnpl]

@zadjii-msft @j4james I addressed:

apps are more likely to expect the dimensions of the addressable cell range, which for us, is determined by the buffer width combined with the viewport height.

with and tested manually (still no TAEF):

@zadjii-msft
No worries; maybe by the time you get to this one, I can figure out the tests 🙃

[j4james]

Tests for sequences like this are typically handled in AdapterTest. Just search for anything using ValidateInputEvent.

For example, this is a test case for the DECRQSS margin query, which first sets up the viewport height to the range it's expecting to see in the query response.

terminal/src/terminal/adapter/ut_adapter/adapterTest.cpp

Lines 1624 to 1630 in 10c6206

	Log::Comment(L"Requesting DECSTBM margins (full screen).");
	_testGetSet->PrepData();
	// Set screen height to 25 - this will be the expected margin range.
	_testGetSet->_viewport.bottom = _testGetSet->_viewport.top + 25;
	_pDispatch->SetTopBottomScrollingMargins(0, 0);
	requestSetting(L"r");
	_testGetSet->ValidateInputEvent(L"\033P1$r1;25r\033\\");

That seems similar to the sort of thing you might want to do. And note that you can access the text buffer the same way as the viewport with _testGetSet->_textBuffer, although I'm not sure about resizing it. You could just assume a buffer width of 100 for your tests, since that's what the PrepData function initializes it with by default (see here).

[michalnpl]

I've added a TAEF test for this. Thank you, @zadjii-msft and @j4james, for guiding me in the right direction.

[j4james]

Nit: I think that std::wstring should automatically cast to std::wstring_view, so you shouldn't need an explicit cast on the textSize parameter. But with that out the way, you might as well embed the fmt::format call directly within the ReturnResponse call and avoid the textSize variable altogether. I suspect we're doing the same thing in a bunch of other places, though, so it's not a big deal.

[michalnpl]

Addressed.

[j4james]

I can't officially approve anything, but this looks good to me. Thanks.

[zadjii-msft]

Thanks for bearing with to write the test!

[zadjii-msft]

Screenshots from body:

For test code:

#include <stdio.h>

int main() {
    printf("\033[18t");
    return 0;
}

Ubuntu:

Terminal (both PowerShell and Conhost):

and for Ubuntu test code:

#include <stdio.h>
#include <unistd.h>
#include <termios.h>

int main() {
    struct termios old_termios, new_termios;
    tcgetattr(STDIN_FILENO, &old_termios);
    new_termios = old_termios;
    new_termios.c_lflag &= ~(ICANON | ECHO);
    tcsetattr(STDIN_FILENO, TCSANOW, &new_termios);
    printf("\033[18t");
    int rows, cols;
    scanf("\033[8;%d;%dt", &rows, &cols);
    tcsetattr(STDIN_FILENO, TCSANOW, &old_termios);
    printf("Terminal size: %d columns x %d rows\n", cols, rows);
    return 0;
}

and for microsoft/terminal test code:

#include <stdio.h>
#include <windows.h>

int main() {
    HANDLE hConsole = GetStdHandle(STD_INPUT_HANDLE);
    DWORD prev_mode;
    GetConsoleMode(hConsole, &prev_mode);
    DWORD new_mode = prev_mode & ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT);
    SetConsoleMode(hConsole, new_mode);
    printf("\033[18t");
    int rows, cols;
    scanf_s("\033[8;%d;%dt", &rows, &cols);
    SetConsoleMode(hConsole, prev_mode);
    printf("Terminal size: %d columns x %d rows\n", cols, rows);
    return 0;
}

Kindly please advise if this is the desired behavior.

[michalnpl]

Going to need another approver to merge this, as @j4james mentioned he could not approve anything officially.

[DHowett]

nit: all of the other uses of fmt in this file use FMT_COMPILE for the format string. That keeps the code size down when this is compiled into Windows' conhost.exe.

Would you mind doing the same? 😄

[DHowett]

Thanks!

[DHowett]

Am I going crazy, or did Refined GitHub change the order of the signoff buttons?