Best way to know if application is inactive in cocoa mac OSX?

Question

So, i am building a program that will stand on a exhibition for public usage, and i got a task to make a inactive state for it. Just display some random videos from a folder on

Answer 1

I'm expanding on Parag Bafna's answer. In Qt you can do

#include 

double MyClass::getIdleTime() {
    CFTimeInterval timeSinceLastEvent = CGEventSourceSecondsSinceLastEventType(kCGEventSourceStateHIDSystemState, kCGAnyInputEventType);
    return timeSinceLastEvent;
}

You also have to add the framework to your .pro file:

QMAKE_LFLAGS += -F/System/Library/Frameworks/ApplicationServices.framework
LIBS += -framework ApplicationServices

The documentation of the function is here