QT 4.7 and Multi-touch (Which input event dev does QT use?)

[liangbowen]

I wrote a multi-touch device driver, which created /dev/input/event4 multi-touch event. and it's been tested by mtdev, but when I use QT touch example "fingerpaint" to test multi-touch, it seems QT cannot recognize multi-touch events produced by /dev/input/event4.

(None of TouchBegin/TouchUpdate/TouchEnd ever triggered)
bool ScribbleArea::event(QEvent *event)
{
printf("TouchUpdate:%d\n",event->type());
switch (event->type()) {
case QEvent::TouchBegin:
case QEvent::TouchUpdate:
{
printf("TouchUpdate\n");

}
case QEvent::TouchEnd:
{
.....


So I wander if QT is hard coded to use other input event device instead of /dev/input/event4 ?
Is there any way to fix this problem? thanks!