From kde-devel  Thu Aug 22 16:37:06 2019
From: Alexander Semke <alexander.semke () web ! de>
Date: Thu, 22 Aug 2019 16:37:06 +0000
To: kde-devel
Subject: Re: Portability of KDE Applications
Message-Id: <71206981.Wtgb4fQeK7 () linux-2rd5>
X-MARC-Message: https://marc.info/?l=kde-devel&m=156649185023202

On Donnerstag, 22. August 2019 11:42:06 CEST Boudewijn Rempt wrote:
> On donderdag 22 augustus 2019 11:38:21 CEST =D0=9D=D0=B8=D0=BA=D0=B8=D1=
=82=D0=B0 =D0=A1=D0=B8=D1=80=D0=B3=D0=B8=D0=B5=D0=BD=D0=BA=D0=BE wrote:
> > > Are you only targeting Linux, or also other operating systems? For
> > > Linux,
> > > appimage probably is the best solution since it is the simplest for t=
he
> > > end
> > > user.
> >=20
> > Well, we also trying to target on Windows - this is also bring other
> > problems, but the application portability problems presents here too.
>=20
> The qrc method helps quite a bit on Windows. For the rest, we assemble our
> deliverable using windeployqt which takes care of all the environment
> variables needed for Qt, and for our own plugins, we have special code so
> that gets found relative to the exe; same for resources we cannot package
> in a qrc file.
I'd say the situation with such resources is better on Windows because Qt's=
=20
QStandardPath works with <APPDIR> or <APPDIR>/data. So, whereever you insta=
ll=20
your application on Windows you can always search and load files from=20
QStandardPath::DataLocation. For example, for the windows installer of=20
LabPlot+Cantor we put all the resources  like images, themes and color sche=
me=20
definitions, icons etc. for LabPlot and all rc files and initialization=20
scripts for Cantor (ca. 30MB in total) into the ./data folder. There is no=
=20
need to compile all this stuf into the executable increasing the memory=20
footprint and slowing down the application start time.

Similar for MacOS.

On Linux this won't work if you install in /opt since QStandardPath doesn't=
=20
know anything about /opt or any other "custom" folders. This should be=20
actually a feature request for Qt to work also on Linux with paths relative=
 to=20
the current path of the executable.

The situation with plugins is similar. On windows you can put everything to=
=20
=2Eplugins/ relative to cantor.exe for example. On Linux Qt only searches i=
n the=20
"default library paths" and evaluates QT_PLUGIN_PATH in addition. But here =
at=20
least you can specify your own paths via QCoreApplication::setLibraryPaths(=
)=20
in the code...

=2D-=20
Alexander