Re: Qt4 Tablet problem
Mon, 3 Apr 2006 11:50:16 +0200
On Mar 31, 2006, at 4:02 PM, Simon Blais wrote:
I have a problem with the tablet in Qt4.1.1. When I move the
stylus quickly the points returned by the QTabletEvents far
apart. It seems like some events are dropped. With Qt3.3.6, the
same thing returned points that are much closer together.
It does not look like the tablet buffer is overflowing, it is
Has something changed in the event processing that would cause this
This can be reproduced by modifying the scribble example to use
tablet events instead of mouse events. ( since I did not find a
tablet example in Qt4)
Added to scribblearea.cpp
void ScribbleArea::tabletEvent( QTabletEvent * event )
if (event->type() == QEvent::TabletPress )
lastPoint = event->pos();
scribbling = true;
else if (event->type() == QEvent::TabletMove && scribbling )
else if (event->type() == QEvent::TabletRelease && scribbling)
scribbling = false;
Added to scribblearea.h
void tabletEvent( QTabletEvent * event );
Is the problem you're seeing that there are some "holes" in the
lines? This is an issue with the scribble example. It seems that it
is able to determine the update area well for a mouse, but not for a
stylus. If you, for example, save the image or change the active
window, the parts will get filled in. Or if you tell it to update
everything, it should generate what you want.
I know it's a shame we don't have a real tablet example at the
moment. It is on the todo list though.
To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with
"unsubscribe" in the subject or the body.
List archive and information: http://lists.trolltech.com/qt-interest/