Comments on: Patch for Lancelot to work with Qt 4.5 (for packagers and distributions)

By: Ivan Čukić

Ivan Čukić — Fri, 13 Mar 2009 10:01:02 +0000

@Kevin Kofler: I haven’t tested it, which is the main reason the patch is not in the SVN (the 4.2 branch).

So, if I were you, I’d wait for the /push/

By: Kevin Kofler

Kevin Kofler — Fri, 13 Mar 2009 09:48:55 +0000

What’s the effect of this patch with Qt 4.4.3? I’m asking because that decides whether we can apply this to all Fedora branches right now or need to wait for the flag day on which we push the Qt 4.5 update.

By: Ivan Čukić

Ivan Čukić — Mon, 09 Mar 2009 22:36:04 +0000

@Alexis Menard: Well, I really hope it will not be needed to have something ‘more reliable for the future’ and that the issue in Qt will go away

Both solutions you’ve proposed appear to be OK, but since I’m not planing to /proclaim/ liblancelot as stable any time soon, I don’t think it really matters. That is, if the bug in Qt gets fixed soon.

By: Alexis Menard

Alexis Menard — Mon, 09 Mar 2009 22:11:45 +0000

For the hiding issue i have to say that is not implemented , so that explain why the layout is not really updated. We have one report for that (before yours i guess so that explain the duplicate).

My idea to bypass this issue is :

- remove the item from the layout when the widget become invisible. and re-add it afterwards.

- reimplement QSizeF QGraphicsLayoutItem::sizeHint and return 0,0 if the item become invisible (invalidate the layout to force an update of sizehints). This should be more cleaner and more reliable for the future.

That is just two ideas coming in my mind tonight .

By: Ivan Čukić

Ivan Čukić — Mon, 09 Mar 2009 22:00:48 +0000

@Alexis Menard: (replied via mail also) If you’re referring to the move off-screen instead of hiding, I’ve reported a bug (http://www.qtsoftware.com/developer/task-tracker/index_html?id=244902&method=entry) with the example code. The bug was marked later as a duplicate, so I have no idea about the progress of it.

BTW, it isn’t really a new hack, I had the issue in question since the QGraphcisView was introduced, it was just bypassed in a different way before. A way that introduced some bugs, so I had it removed.

About the other, less dirty, hacks, I haven’t really got the time to isolate the problems, but will eventually.

By: Alexis Menard

Alexis Menard — Mon, 09 Mar 2009 21:34:37 +0000

Mmmmm the patch is very hackish. I am very surprised that you need to do that with 4.5.0. In many plasma applets, we are removing hacks and you need new ones. My point is : were you able to reproduce the problem in a pure Qt app? And more did you report that to Qt Software? I prefer a proper patch in qt-copy which means 4.5.x than a patch directly in the applet which perhaps won’t work with 4.5.1. If you provide me the test case i will be glad to look at it and instead you will be able to point a proper qt-copy patch .