[SOLVED]How to control refreshing qml view?

av2306

Hi,

QML View with C++ Model. QAbstractListModel for c++ model and ListView on QML View with delegates.

When I launch view, CPU goes very high. I am suspecting QAbstractListModel::data called for every few milliseconds. How to control this? Any other inputs to control cpu?

Thanks.

p3c0

It should not happen. Are you doing any heavy processing in it ?
QAbstractListModel::data will be called only when needed from the delegate. And on the first launch by default it should not even load all the items unless requested.

av2306

No heavy processing.

On What basis, delegate requests data from model?

p3c0

Whenever delegates are instantiated.

av2306

There is an animation control in view item. Delegate updates the animation by using model data in delegate. And, items are getting added and deleted based on animation status. Should I destroy items manually? Any inputs.

p3c0

Does the ListView load all of the Items initially ?

av2306

It's empty initially. C++ model fetches data from server and inform to AbstractListModel through signals (Add, update, del). Whenever any changes on model, it reflects immediately on view. Any inputs?

p3c0

bq. C++ model fetches data from server

Have you made sure that this operation is not doing any CPU intensive work ?

av2306

Verified with QML View and without QML View. When I launched ui, then only I can see cpu high. Otherwise, it's very normal. Added logs in AbstractListModel overridden functions. Model emit signal for every change. But, "data" fired many times. So, I suspected on "data" calling from qml.

p3c0

May be somewhere the List is getting refilled again on each added Item. Can you post the code ?

av2306

Thank you for your inputs. My TCP Server sends 100+ events to client in a second. Controlled the signals passing to view. Now, cpu normal. Thank you again.

p3c0

Ok. You're Welcome :)
Please mark the post as solved.