Re: Announce: AdaStudio-2021 release 01/10/2021 free edition

[Fernando Oleo Blanco <irvise_ml@irvise.xyz>]

Hi,

I have been playing today with qt5ada and I think I can shed some light 
on the issue.

The Ada sources that call the Qt procedures are in the 
AdaStudio/qt5ada/qt5adasrc.tar.bz2 file. That is the source file. There 
are no C files there. That library contains all of the Ada wrapper.

However, that is indeed not enough to use it. It requires a fully 
functional Qt5 installation (and a very complete one, with bells and 
whistles). The binaries are provided in the other *.tar.bz2 files 
(except the demos file). There is also the qt5adax86-64.tar.bz2 file 
which weights about 6Mb. That seems to be the relevant file to build 
qt5ada from source in Linux. It comes with different files to setup the 
file structure and environment. I must admit, I have not tried to build 
it with the provided files in qt5adax86-64.tar.bz2

These "build files" expect you to have a Qt5 installation in your local 
/usr/local folder. I suppose that is where the qt5.15x86-64.tar.bz2 
comes into place, after all, it should unpack in the directory written 
in the environment file.

Of course, the question is: where are the instructions to build this all 
from source? The short answer is in the document "How to use 
Qt5Ada.docx" that is present in AdaStudio/qt5ada. That sheds more light 
into the procedure. But it still expects you to use the precompiled Qt5 
binary. And, I must be honest, it is not clear and easy to follow, you 
need to adapt the generic instructions to what is on your system...

Then the question becomes: "How can I build _everything_ from source? 
Specially with the system provided libraries, such as the system 
provided Qt5." Well... That is not so simple. I understand why Leonid 
has set up things this way. Correctly setting the compiler flags and 
directories for system installed libraries is a nightmare. I tried to 
compile qt5ada with my system provided Qt5 (OpenSUSE Tumbleweed), it is 
not trivial _at all_. There can be problems with the Qt5 version, there 
can be problems with the plugins, compiler flags, etc. Can it be done? 
Most likely, but it will require some elbow grease. There is a reason to 
why most Qt projects use CMAKE to build and link themselves; because it 
is not an easy task.

So I would say that the instructions need to be cleaner and that in its 
current state, there is only one easy solution to building qt5ada, and 
it requires the binaries provided. But I would also say that all the 
source files needed are in there. The prebuilt Qt5 binary seems to be 
the standard unmodified Qt5 distribution, so no surprises there. And 
that a lot of extra work would be needed to make qt5ada work seamlessly 
with the system provided libraries.

Regards,
-- 
Fernando Oleo Blanco
https://irvise.xyz