Re: Is it possible/acceptable to create a component in Gambas that depends on a shared library?

[Claus Dietrich <claus.dietrich@xxxxxxxxxx>]

Am 06.02.26 um 21:16 schrieb Lee:
> The recent thread on reading barcodes prompted me to revisit this idea.
>
> A while back I wrote a project that used "droidcam" and "zbarcam" to 
> read barcodes using a smartphone. It works adequately, but managing 
> each external process to make the user experience less cumbersome is 
> more cumbersome in the code.
>
> It would be nice to be able to manage the reader directly from Gambas. 
> But, it is even acceptable to create a component in Gambas that 
> depends on a shared library?
>
> I see that gb.scanner relies on `scanimage`, but that is a 
> command-line tool the existence of which is easily tested with 
> System.Exist(). Also, I see that gb.openssl relies on the "openssl" 
> library but that component is written in C and appears to statically 
> link with the library.
>
> Is there a "proper" way to do what I am asking including relatively 
> easily testing for the existence of the shared library to raise an 
> error if it does not exist? Or is creating a component in Gambas that 
> relies on a shared library (perhaps highly) discouraged if not prohibited?

Hi Lee

I just had similar thoughts and questions. My newest class for reading 
QR and barcodes is using cli-tools of the zbar-tools or 
zxingbar-cpp-tools package. Like in the Scanners class I am testing the 
platform for the existence of necessary tools:

If (Not System.Exist("zbarimg")) And (Not System.Exist("ZXingReader")) Then

....

In any project you can add "libraries" an "further references" in the 
project-properties-dialog. I was wondering if this would allow to bring 
along all dependencies with the component. Unfortunately I haven't seen 
an example or documentation about this yet.

To include packages like zbar-tools is something which is feasible in 
the the installer dialog (step. 5 Extra Dependencies). I am assuming 
that this is also usable for Gambas components.

Hope that Benoît can provide some infos and references for getting a 
better picture.

Best regards, Claus