Repository: terminal
Issue: Mouse input differences when using ENABLE_VIRTUAL_TERMINAL_INPUT
Labels: Product-Conpty,Area-Input,Issue-Bug

### Windows Terminal version

1.16.10261.0

### Windows build number

Microsoft Windows [Version 10.0.19045.2846]

### Other Software

_No response_

### Steps to reproduce

Compile this C code as a console application, and try it in both conhost and Windows Terminal.  (Move the mouse over the window.)

```
#include <stdio.h>
#include <windows.h>
#include <ctype.h>

int main(void)
{
    /* Get handles for stdin and stdout */
    HANDLE stdinH = GetStdHandle( STD_INPUT_HANDLE );
    HANDLE stdoutH = GetStdHandle( STD_OUTPUT_HANDLE );
    if (!stdinH || !stdoutH
     || (stdinH == INVALID_HANDLE_VALUE )
     || (stdoutH == INVALID_HANDLE_VALUE ))
    {
        return 1;
    }
    
    /* Set console output mode */
    DWORD outMode;
    if (!GetConsoleMode(stdoutH, &outMode))
    {
        return 2;
    }
    DWORD newMode = outMode;
    newMode |= ENABLE_PROCESSED_OUTPUT | ENABLE_VIRTUAL_TERMINAL_PROCESSING;
    newMode &= ~ENABLE_WRAP_AT_EOL_OUTPUT;
    newMode &= ~DISABLE_NEWLINE_AUTO_RETURN;
    newMode &= ~ENABLE_LVB_GRID_WORLDWIDE;
    if (!SetConsoleMode(stdoutH, newMode))
    {
        return 3;
    }
    
    /* Set console input mode */
    DWORD inMode;
    if (!GetConsoleMode(stdinH, &inMode))
    {
        SetConsoleMode(stdoutH, outMode);
        return 4;
    }
    newMode = inMode;
    newMode &= ~ENABLE_ECHO_INPUT;
    newMode &= ~ENABLE_INSERT_MODE;
    newMode &= ~ENABLE_LINE_INPUT;
    newMode |= ENABLE_MOUSE_INPUT;
    newMode &= ~ENABLE_PROCESSED_INPUT;
    newMode &= ~ENABLE_QUICK_EDIT_MODE;
    newMode |= ENABLE_EXTENDED_FLAGS;  /* Needed when changing _QUICK_EDIT_MODE */
    newMode |= ENABLE_WINDOW_INPUT;
    newMode |= ENABLE_VIRTUAL_TERMINAL_INPUT;
    //newMode &= ~ENABLE_VIRTUAL_TERMINAL_INPUT;
    if (!SetConsoleMode(stdinH, newMode))
    {
        SetConsoleMode(stdoutH, outMode);
        return 5;
    }
    
    /* Enable keypad application mode */
    printf("\x1b=");
    
    while (1)
    {
        DWORD numRead;
        INPUT_RECORD rec;
        BOOL successB = ReadConsoleInput( stdinH, &rec, 1, &numRead );
        if ( !successB || (numRead != 1) )
        {
            break;
        }
        
        if (rec.EventType == KEY_EVENT)
        {
            char c = rec.Event.KeyEvent.uChar.AsciiChar;
            printf(" KEY %s ", rec.Event.KeyEvent.bKeyDown ? "down" : "up  ");
            if (isprint(c))
            {
                printf("'%c'\n", c);
            }
            else
            {
                printf("\\x%02x'\n", (int)c);
            }
            
            /* Exit when X pressed */
            if ((c == 'x') || (c == 'X'))
            {
                break;
            }
        }
        else if (rec.EventType == MOUSE_EVENT)
        {
            printf(" MOUSE dwMousePosition=%d,%d  dwButtonState=0x%08x  dwControlKeyState=0x%08x  dwEventFlags=0x%08x\n",
                    (int)rec.Event.MouseEvent.dwMousePosition.X, 
                    (int)rec.Event.MouseEvent.dwMousePosition.Y,
                    (int)rec.Event.MouseEvent.dwButtonState,
                    (int)rec.Event.MouseEvent.dwControlKeyState,
                    (int)rec.Event.MouseEvent.dwEventFlags );
        }
    }
    
    /* Clean up */
    SetConsoleMode(stdoutH, outMode);
    SetConsoleMode(stdinH, inMode);

    return 0;
}
```

### Expected Behavior

The same behaviour in both conhost and Windows Terminal.

### Actual Behavior

In Windows Terminal, I receive mouse input only as virtual terminal input sequences.  In conhost, I receive mouse input only as MOUSE_EVENT INPUT_RECORDs.

My guess is this is an intentional difference rather than a bug, but I wanted to ask some questions.  I would like my program to work the same whether run in Windows Terminal or conhost.  I would like to enable ENABLE_VIRTUAL_TERMINAL_INPUT to get VT sequences for key presses at least.  Here are my questions:

1. Is it possible to get the same mouse input behaviour (either VT sequences or input records) in both conhost and Windows Terminal, with ENABLE_VIRTUAL_TERMINAL_INPUT enabled?  If so how?  (Maybe a setting for Windows Terminal that I couldn't find?)
2. Where can I find documentation of the mouse input VT sequences?

Thanks