grapGesture - QScrollArea scroll with 1 Finger touch

Andy314

Hello,
I found this way

QScroller::grabGesture(ui->scrollArea, QScroller::LeftMouseButtonGesture);

to avoid the annoying 2-Finger scroll. With this code I can scroll with one Finger.

But I found a problem.
When I click on a QPushButton in this scrollarea to open a new Dialog with an other one-Finger-ScrollArea in it, the scrolling does not work here.
When I disable the one-Finger scrolling in first area with the Button it, the second dialog works.
Only one grabGesture possible - must I disable it - on disabeling in the first Dialog in the on click even the app crashes after I close the 2. Dialog ????????????

mrjj

@Andy314 said:

QScroller::grabGesture

hii
what you u also call
QScroller::grabGesture
for the second
one-Finger-ScrollArea ?

Andy314

Yes, of course !

Andy314

When I move the Button which calls the 2. Dialog out of the scrolling area, all works.
So calling a scrollarea from an other scroll area is not posssible.
Maybe in the _clicked event processing the gesture processing is in work and prevents other gesture processings ?
What can I do ?

Addition:
I have checked my thesis.
In the Button onClicked I start a timer in 100 ms .
In the timer-even I open the 2. dialog -> it works.

Hm, a little bit roundabout ! Is there an more easy and direct way ?

mrjj

well
when you open this dialog, do you call exec() ?
That will start a local event loop and it might be the reason.

Andy314

Yes, I start a modal dialog with exec !

mrjj

@Andy314
ok, that might do strange stuff as it stays in there.
try calling show() instead to test

note, show() dont block so if u have code

dia.exec()
code that do something with dialog stuff after OK

switching to show() wont work.

Andy314

@mrjj
Indeed with show it works.

Any ideas how perform it with exec ?

mrjj

@Andy314
Only as you self discovered to use a timer to
start it via other signal.

Andy314

@mrjj
Thank you for you help, here is my short solution:

QMetaObject::invokeMethod(this, "functionToCall", Qt::QueuedConnection);

mrjj

@Andy314 said:

QueuedConnection

ah, yes. i wondered if it would work.
And it does. super.