Re: [Plplot-devel] Tentative plan for removing our support of Qt4

[António R. T. <ar...@gm...>]

Hi Allan,
I really think that is safe to remove qt4 support. Sooner or later qt4 will
not be available by default in  a normal linux distribution.

So I agree with your proposed roadmap.

cheers,


On Mon, Sep 2, 2019 at 9:36 PM Alan W. Irwin <Ala...@gm...>
wrote:

> Hi António:
>
> Your fix of the serious Qt5 font configuration bug for PLplot made our
> Qt5 results in PLplot-5.15.0 essentially as good as our Qt4 results
> for the first time ever.  So ever since that release it has been on my
> mind to greatly reduce the complexity of our build-system *and*
> testing of our Qt and PyQt components by only supporting Qt5 (i.e.,
> dropping our support for Qt4).
>
> The current build-system situation is Qt4 is looked for first, but if
> it is not found Qt5 is used as a backup with the exception that Qt5 is
> forced if the user specifies -DPLPLOT_USE_QT5=ON (which defaults to
> OFF).  So my proposed plan to reach the above goal with minimum
> disruption for users is the following:
>
> * PLplot-5.16.0.  Use the exact same build system logic except that 4
>    and 5 are swapped.  That is Qt5 is looked for first, but if it is
>    not found Qt4 is used as a backup with the exception that Qt4 is
>    forced if the user specifies -DPLPLOT_USE_QT4=ON (which defaults to
>    OFF).  Warn in the release notes of this change and the
>    corresponding replacement of the PLPLOT_USE_QT5 option with
>    PLPLOT_USE_QT4 and also mention we plan to deprecate Qt4
>    support in the next release and remove it in the next release
>    after that.
>
> * PLplot-5.17.0.  Deprecate Qt4, i.e., use it as a fall back from
>    Qt5 *only* if the users sets -DPLPLOT_QT4=ON.  Warn in the release
> notes of
>    this change and also warn we plan to remove support for Qt4 in
>    the next release.
>
> * PLplot-5.18.0.  Completely remove support for Qt4 which will finally
> achieve the
>    desired simplifications mentioned above.
>
> As someone here with a large familiarity with Qt, I would appreciate
> you letting me know if you forsee any trouble with this overall plan
> to remove our Qt4 support.  And comments on this plan from the other
> PLplot developers here are also encouraged.
>
> I will likely implement the 5.16.0 part of the above plan late this
> week if there are no strong disagreements expressed here in the
> next several days.
>
> Alan
> __________________________
> Alan W. Irwin
>
> Programming affiliations with the FreeEOS equation-of-state
> implementation for stellar interiors (freeeos.sf.net); the Time
> Ephemerides project (timeephem.sf.net); PLplot scientific plotting
> software package (plplot.org); the libLASi project
> (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
> and the Linux Brochure Project (lbproject.sf.net).
> __________________________
>
> Linux-powered Science
> __________________________
>


-- 

António Rodrigues Tomé
Universidade da Beira Interior
Instituto D. Luís (lab associado)
email address:
ar...@gm...
ar...@ub...
http://www.researcherid.com/rid/A-5681-2013