QListView unresponsive when painting images

[isplasher]

I just made a new discovery!
While surfing on the net I stumbled upon QPixmapCache. While thinking it was the solution to my issue, i set it up.
Unfortunately the issue still remains, but i discovered a symptom.
To be sure i setup the caching correctly i made it print "from cache", "new image" depending on if the image was fetched from the cache, or was created anew.
This showed some interesting results. On start it printed "new image" about 15 times as expected. I Expected 15 times because i set the limit in the fetchMore
method to 15.
Then i try moving the mouse inside the ListView, without scrolling, just moving the mouse around abit. This made the console go wild with alot of mixed messages of
"from cache" and "new image", which about 60-70% of the messages were "new image". With this i think i finally narrowed down the cause of why the gui is lagging.
It suggests that somehow the view is not only painting the needed (visible) images, but everything when you move your mouse inside the view.
This however hasn't solved my problem, so please don't think that i still don't need help. I just wanted to give an update on what i have found.

[wysota]

What happens if you increase the size of the pixmap cache?

[isplasher]

What happens if you increase the size of the pixmap cache?

Wow, so i just multipled the cache with 1000 (10240*1000) and it helped alot.
The gui was still lagging but not as much as before.

[wysota]

Wow, so i just multipled the cache with 1000 (10240*1000) and it helped alot.
The gui was still lagging but not as much as before.

The effect you observed before was caused by cache flickering. How large are your images? Isn't the lagging caused by scaling pixmaps?

[isplasher]

The effect you observed before was caused by cache flickering. How large are your images? Isn't the lagging caused by scaling pixmaps?

Oh i see.. I completely forgot about the image size.
The images i use mostly have the dimensions 1500x2100px. They are about 2mb each.
After reading that i now realize why all this was happening.. (facepalms)
Anyway, yes, i think you're right about the pixmap scaling. Do you have any solutions, other than using smaller images?

[wysota]

Scale them once before adding them to your model and use the thumbnail instead of the original image.

[isplasher]

Right.
Was thinking of the same approach.
Thank you for your help, kind sir.