Dolphin scroll lagging when hidden folders symlinks are in a visible area. The attached video explains everything. The bug does not appear to be related to the theme icon. I also tested with Okygen and several other.
No lag when scroll
Youtube video link >> http://www.youtube.com/watch?v=N4v4CZEWGNA&feature=youtu.be
Thanks for the bug report! I can confirm the problem.
Git commit 381b17964d49259955eb5c5e537d290b26c162ef by Frank Reininghaus.
Committed on 14/08/2013 at 21:44.
Pushed by freininghaus into branch 'KDE/4.11'.
Fix slow scrolling when hidden files or symbolic links are shown
The problem was that we drawed the overlays using KIconLoader, which can
be very slow, every time an item appeared on the screen. This commit
makes sure that not only the icon, but the icon including overlays is
cached in QPixmapCache. Therefore, the overlay drawing is done just once
for each icon+overlays combination.
For previews, the overlay drawing is done in KFileItemModelRolesUpdater
just after the preview is received.
Related: bug 314339
M +16 -0 dolphin/src/kitemviews/kfileitemmodelrolesupdater.cpp
M +18 -19 dolphin/src/kitemviews/kstandarditemlistwidget.cpp
M +1 -1 dolphin/src/kitemviews/kstandarditemlistwidget.h