Qt 4.7.4: Is there a way to find out the status of CAPS LOCK?

Question

I know there were earlier problems with this in < 4.7.4 Qt versions. has this been resolved?

Answer 1

I don't know any Qt solution.

However this code should work on both windows (not tested) and x11-based os (works on linux)

#include <X11/XKBlib.h>
#include <QX11Info>

bool capsOn()
{
#ifdef Q_WS_WIN // MS Windows version
    return GetKeyState(VK_CAPITAL) == 1;
#elif Q_WS_X11 // X11 version
    unsigned int n = 0;
    Display *d = QX11Info::display();
    XkbGetIndicatorState(d, XkbUseCoreKbd, &n);
    return (n & 0x01) == 1;
#else
# error Platform not supported
#endif
}

On X11 don't forget to add -lX11 to LIBS in your qmake project file.

I don't exactly know how to do this on OS X. If you need it, take a look at IOHIKeyboard and its's alphaLock() function. Also check this, especially the function darwinQueryHIDModifiers.