Re: [PATCH] Move some term code from lib to src

[Tim Rühsen]

Hey Jose !

On 30.04.20 10:03, Jose E. Marchesi wrote:
> 
> Hi Tim.
> 
> Finally completed the library interface revamp.  Sorry it took a while,
> been busy :)
> 
>     The attached patch is for discussion.
>     
>     It moves some (IMO application) code from lib/ to src/poke.c.
>     
> Right now, the situation is:
> 
> 
>                           (textstyle.h)
>         +-----------+              +--------------+
>         |  libpoke  |<-------------| libtextstyle |
>         +-----------+              +--------------+
>              |
>              |  (pk-term.h)
>              v
>         +-------------+
>         | application |
>         +-------------+
> 
> The user of libpoke can make use of the pk-term services, which includes
> class handling, and supports the same set of command-line options like
> --color, but that doesn't imply the application uses or is even aware of
> libtextstyle itself.
> 
> What you are proposing is:
> 
>                           (textstyle.h)
>         +-----------+              +--------------+
>         |  libpoke  |<-------------| libtextstyle |
>         +-----------+              +--------------+
>              |                      /
>              |  (pk-term.h)        /
>              v                    /
>         +-------------+          /
>         | application |<--------+
>         +-------------+    (textstyle.h)
> 
> 
> The problem I see with this approach is that it forces applications
> using libpoke to be aware of libtextstyle.
> 
> Now, it may be argued that libpoke is not the right place from where to
> offer terminal services as such.  Then we would like to do something
> like:
> 
>                           (textstyle.h)
>         +-----------+              +--------------+
>         |  libpoke  |<-------------| libtextstyle |
>         +-----------+              +--------------+
>              |                      /
>              |                     /
>              v                    /
>         +-------------+          /
>         | application |<--------+
>         +-------------+    (textstyle.h)
> 
> 
> Note how pk-term is no longer exported by libpoke.  Therefore, the
> application (in this case poke.c) would need to use the libtextstyle
> services directly.
> 
> But what would be best would be to make libpoke to use printing services
> provided by the application, via callbacks:
> 
>         +-----------+
>         |  libpoke  |
>         +-----------+
>              |
>              |
>              v
>         +-------------+               +--------------+
>         | application |<--------------| libtextstyle |
>         +-------------+               +--------------+
>                             (textstyle.h)
> 
> The callback interface, defined in libpoke.h, should understand things
> like style classes and hyperlinks.  This is my favorite approach:
> 
> - No dependendency of libpoke to libtextstyle.
> 
> - Makes it possible to embed libpoke in programs that provide their own
>   information presentation meanings, such as X-window windows or their
>   own prompts.
> 
> - The .css file would be distributed by the application (poke) and not
>   by libpoke.
> 
> WDYT?

I fully agree that this is a clear design and the best I can think of as
well.

After your very good and surely time-taking explanations above, I feel a
bit shabby for my short answer :-)  But, yes, very good !

Regards, Tim

signature.asc
Description: OpenPGP digital signature