[Qt-interest] System wide events

[Poss3x]

Hi,

in my app I'd like to catch system wide events, especially mouse click 
and mouse movement. System wide means that I do not want to capture the 
events dispatched by my Qt app but in my case by Win32.

The present idea is to react on certain events in the system, especially 
a drag event in explorer or desktop.


For the desktop I thought it would be easy to install an event filter 
object in the application's desktop widget, like this:


class DesktopMouseListener : public QObject
{
public:
     DesktopMouseListener(QObject * p) : QObject(p) {};

     bool eventFilter(QObject * watched, QEvent * event)
     {
         if(event->type() == QEvent::MouseButtonPress)
         {
             QMouseEvent * me = (QMouseEvent*)event;
             if(me->button() == Qt::LeftButton)
                 qDebug("desktop clicked...");

             return true;
         }

         return false;
     }
};


later installed like this:

QApplication::desktop()->installEventFilter(new DesktopMouseListener(this));


But this does not work as eventFilter(); it seems that desktop widget 
does not handle "desktop clicks".


I also found in the API:

 >>
bool QCoreApplication::winEventFilter ( MSG * msg, long * result ) [virtual]

The message procedure calls this function for every message received. 
Reimplement this function if you want to process window messages msg 
that are not processed by Qt. If you don't want the event to be 
processed by Qt, then return true and set result to the value that the 
window procedure should return. Otherwise return false.

It is only directly addressed messages that are filtered. To handle 
system wide messages, such as messages from a registered hot key, you 
need to install an event filter on the event dispatcher, which is 
returned from QAbstractEventDispatcher::instance().
<<

So I installed an event filter on the event dispatcher, but it did not 
work either. The left button press is only triggered when clicking 
inside the app itself. But this is not what I want.


So my question:

Is there any solution to capture events like I described?

Thnx