Mailinglist Archive: opensuse-bugs (14244 mails)

< Previous Next >
[Bug 433130] [Qt4-UI] Poor performance when switching to expert mode in runlevel editor
  • From: bugzilla_noreply@xxxxxxxxxx
  • Date: Thu, 16 Oct 2008 11:56:12 -0600 (MDT)
  • Message-id: <20081016175612.CCFA5245390@xxxxxxxxxxxxxxxxxxxxxx>
https://bugzilla.novell.com/show_bug.cgi?id=433130

User sh@xxxxxxxxxx added comment
https://bugzilla.novell.com/show_bug.cgi?id=433130#c10


Stefan Hundhammer <sh@xxxxxxxxxx> changed:

What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |FIXED




--- Comment #10 from Stefan Hundhammer <sh@xxxxxxxxxx> 2008-10-16 11:56:12 MDT
---
This is very likely really a bug inside Qt, but I found a workaround:

While inserting items into a QTreeWidget that adapts its column widths
automatically to its content
(QTreeWidget::header()->setResizeMode( QHeaderView::ResizeToContents ) ),
Qt spends a lot of time trying to figure out the new column width with each new
item that is inserted. It looks like this is in the order of O(n^2). That's
also why it is really bad with relatively small numbers already: It took 8-10
seconds on my machine with just 300 items with this example:

http://svn.opensuse.org/svn/yast/trunk/libyui/examples/Table-many-items.cc

Workaround:

Now setting that ResizeMode to "Fixed" before inserting items and restoring it
(and ResizeColumnToContent() for each column) afterwards.

Dirk, this might also be or become a problem for other Qt apps.


--
Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

< Previous Next >
References