Detecting screen recording settings on macOS Catalina

Question

What\'s is a reliable way to detect if user has enabled this API?

CGWindowListCreateImage returns a valid object even if screen recording API is disable

Answer 1

@marek-h posted a good example that can detect the screen recording setting without showing privacy alert. Btw, @jordan-h mentioned that this solution doesn't work when the app presents an alert via beginSheetModalForWindow.

I found that SystemUIServer process is always creating some windows with names: AppleVolumeExtra, AppleClockExtra, AppleBluetoothExtra ...

We can't get the names of these windows, before the screen recording is enabled in Privacy preferences. And when we can get one of these names at least, then it means that the user has enabled screen recording.

So we can check the names of the windows (created by SystemUIServer process) to detect the screen recording preference, and it works fine on macOS Catalina.

#include 
#include 

bool isScreenRecordingEnabled()
{
    if (@available(macos 10.15, *)) {
        bool bRet = false;
        CFArrayRef list = CGWindowListCopyWindowInfo(kCGWindowListOptionAll, kCGNullWindowID);
        if (list) {
            int n = (int)(CFArrayGetCount(list));
            for (int i = 0; i < n; i++) {
                NSDictionary* info = (NSDictionary*)(CFArrayGetValueAtIndex(list, (CFIndex)i));
                NSString* name = info[(id)kCGWindowName];
                NSNumber* pid = info[(id)kCGWindowOwnerPID];
                if (pid != nil && name != nil) {
                    int nPid = [pid intValue];
                    char path[PROC_PIDPATHINFO_MAXSIZE+1];
                    int lenPath = proc_pidpath(nPid, path, PROC_PIDPATHINFO_MAXSIZE);
                    if (lenPath > 0) {
                        path[lenPath] = 0;
                        if (strcmp(path, "/System/Library/CoreServices/SystemUIServer.app/Contents/MacOS/SystemUIServer") == 0) {
                            bRet = true;
                            break;
                        }
                    }
                }
            }
            CFRelease(list);
        }
        return bRet;
    } else {
        return true;
    }
}