Problem with QGraphicsScene mouse move event

Nesbit

Hello,

I re-implement mouse event handlers in a subclass of QGraphicsScene and have a problem with the mouseMoveEvent() function.

The following code works (i.e. when I press the left/middle/right buttons, hold and move, I have the text displayed):
@void Scene::mouseMoveEvent(QGraphicsSceneMouseEvent* e)
{
std::cout<<"hehe"<<std::endl;
}@

but the following does not (nothing happens even if I press the left button):
@void Scene::mouseMoveEvent(QGraphicsSceneMouseEvent* e)
{
if(e->button()==Qt::LeftButton) std::cout<<"hehe"<<std::endl;
}@

The following code also works
@void Scene::mousePressEvent(QGraphicsSceneMouseEvent* e){
if(e->button()==Qt::LeftButton) std::cout<<"hehe"<<std::endl;
}@

Hope it's not a bug of Qt and somebody can help.
Thank you so much.

? Offline

"QGraphicsSceneMouseEvent::button":http://qt-project.org/doc/qt-4.8/qgraphicsscenemouseevent.html#button

bq. Returns the mouse button (if any) that caused the event.

So left click button had caused the event.
You can use:
@
if (Qt::LeftButton & e->buttons())
{
// left buttons is pressed
}
@

? Offline

I encountered the same problem. Did anyone know what is the problem and solution?
The problem actually is the subclass_QGraphicsScene::mouseMoveEvent() is not invoked button move around with left button down, but the mousePressEvent() and mouseRelease() working fine.
Thanks much for any idea.

? Offline

I encountered the same problem. Did anyone know what is the problem and solution?
The problem actually is the subclass_QGraphicsScene::mouseMoveEvent() is not invoked button move around with left button down, but the mousePressEvent() and mouseRelease() working fine.
Thanks much for any idea.