Get the mouse position in macOS with C++

get_mouse_position_macos.cpp

#include <ApplicationServices/ApplicationServices.h>
#include <iostream>
#include <string>

///print out location in a nice way to std cout
void fancyPrintLocation(CGPoint location);

/// This callback will be invoked every time the mouse moves.
CGEventRef myCGEventCallback(CGEventTapProxy proxy, CGEventType type,
                  CGEventRef event, void *refcon)
{
    if (type != kCGEventMouseMoved)
    {
        return event;
    }
    
    CGPoint location = CGEventGetLocation(event);
    fancyPrintLocation(location);
    return event;
}

int main(void)
{
    CGRect screenBounds = CGDisplayBounds(CGMainDisplayID());
    printf(
           "The main screen is %dx%d\n",
           (int)screenBounds.size.width,
           (int)screenBounds.size.height);
    
    CFMachPortRef eventTap = CGEventTapCreate(
                                              kCGSessionEventTap,
                                              kCGHeadInsertEventTap,
                                              kCGEventTapOptionDefault,
                                              (1 << kCGEventMouseMoved),
                                              myCGEventCallback,
                                              NULL);
    
    if (!eventTap)
    {
        fprintf(stderr, "failed to create event tap\n");
        exit(1);
    }
    
    CFRunLoopSourceRef runLoopSource = CFMachPortCreateRunLoopSource(
                                                                     kCFAllocatorDefault,
                                                                     eventTap,
                                                                     0);
    CFRunLoopAddSource(
                       CFRunLoopGetCurrent(),
                       runLoopSource,
                       kCFRunLoopCommonModes);
    
    CGEventTapEnable(eventTap, true);
    CFRunLoopRun();
    exit(0);
}

void fancyPrintLocation(CGPoint location)
{
    std::string clearLastLine = ("\33[2K\r(");
    std::string printOut =
    clearLastLine +
    std::to_string((int)(location.x)) +
    std::string(", ") +
    std::to_string((int)(location.y)) +
    std::string(")");
    std::cout << printOut << std::flush;
}