[Paraview-developers] Requiring Qt 4.6 for ParaView 3.8

[Moreland, Kenneth]

How good is Qt at maintaining forward compatibility with, for example, its ui file format.  If all the developers are on 4.6 and someone makes a change with Qt Designer to one of the ui files, will the change break all the 4.5 builds?

-Ken


On 2/8/10 8:21 AM, "Utkarsh Ayachit" <utkarsh.ayachit at kitware.com> wrote:

Those are indeed good and valid points. We were discussing a possible policy and here's what we have. What does everybody think?

* There will 1 officially supported Qt version. This is the Qt version our binaries will be released with. The officially supported Qt version will remain fixed for 2 revisions e.g. 3.8 and 3.10 both will officially support the same Qt version. There will be a minimum Qt version below which it cannot compile (for 3.8 this will be Qt 4.5). However the minimum version may go higher in every release (but <= the official Qt version) depending on whether we end up using some latest Qt functionality  provided by the officially supported release.

* Let Qt 4.6 be an exception, since Qt 4.6 is required to build on Snow Leopard and it's a nightmare to support different versions on different platforms. So 3.8 and 3.10, will be requiring Qt 4.6 (with min. Qt 4.5)

* CMake will flag an error when the Qt version is below the minimum; a warning when the Qt version is below the official  (but above the min.) and be silent with the Qt version is same as the official or above.

* Any user-interface related issues for any Qt version, but the official version may not be addressed.

* We'll always have a dashboard machine compiling with the latest Qt so that there will be no surprises when we switch to the latest Qt.

* After two consecutive major releases (not patch releases) have stuck with the same QT version and it's time to upgrade to a newer Qt version, we'll pick the latest Qt version released at least 3 months prior to the release.

How does that sound? If it's acceptable, I can post it to the Wiki as the official policy for Qt version updating.

Utkarsh


On Mon, Feb 8, 2010 at 3:32 AM, Stephane PLOIX <stephane.ploix at edf.fr> wrote:

Hi,

I think that we have to be carefull : with the branding refactoring making it easy to build applications on top of ParaView components, and the PV_INSTALL_DEVELOPMENT options, ParaView should now be considered more like an SDK than a stand-alone application.

As more and more applications are built on top of PV, changing the version of Qt will impact all those applications, you should then have a clear policy regarding those versions, and give a advanced warning of any changed to come.

Some possible policy would be :
at each release of a new stable version of Qt, PV will support both the new and the old versions for 1 year, and drop the previous version after that
or
each stable version of ParaView will support both the lastest stable version of Qt and the previous one

or whatever, but please make it a public policy so that we know what to expect.

Best
Stephane




berk.geveci at kitware.com
Envoyé par : paraview-developers-bounces at paraview.org 07/02/2010 21:48

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burlen.loring at gmail.com

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Re: [Paraview-developers] Requiring Qt 4.6 for ParaView 3.8




I wouldn't object to supporting 4.5 and 4.6. I think setting up 1-2 dashboards to verify building with 4.5 would be enough. We don't run into Qt specific bugs too often anyway. I defer to Utkarsh though.

Also, if there is an attractive feature on the latest version of Qt that will make our lives much easier, we are likely to move to it and not support the previous version. So, I don't want to have an official rule about supporting more than 1 version.

-berk


On Sun, Feb 7, 2010 at 3:08 PM, burlen <burlen.loring at gmail.com <mailto:burlen.loring at gmail.com> > wrote:
Will this mean that PV won't build with any thing less than Qt 4.6?
I wonder if it would make sense to have a small range of supported versions rather than a single one?

It's currently the case that with qt anything less than 4.5 pv fails to compile (even if you remove the version test in cmakelists) because pv uses some qt classes that were only added to 4.5. In my opinion it would be a burden to pv users to get too far ahead of the various KDE supported distro's packages. eg. Kubuntu 9.10 reports qt version 4.5.2. KUbuntu 8.04.4 LTS reports qt version 4.3.4.