[comp.lang.eiffel] Widgets and Eiffel

day@grand.UUCP (Dave Yost) (12/22/88)

From: Vincent Phuah <vp01@gte.com>
Date: Tue, 15 Nov 88 16:04:16 EST

              Using X Widgets in Eiffel
              --------------------------
  I assume it is fair to say that the graphic library in the current
release has a lot of glitches and doesn't work correctly at times.  
While waiting for their next release, I am curious to 
know whether there have been any success in 
using the X Widget Sets (e.g. Athena and HP) in Eiffel. 

  Although Eiffel allows calls to external C routines, only basic C type
parameters can be passed between C and Eiffel. This severely limits 
the type of external C routines that can be called. For example,  
I think it is not possible to call the routines provided by the X Toolkit
because of the complex data structures that need to be passed
between these routines and Eiffel.  Also, there is a further 
complication when calling  external C routines
which have "#include files" in them. Currently, there is no
facility in Eiffel to include these files which leads to
an interesting problem - how to call a external function which has
a return type defined in the "include files". 

    These are the few problems I have encountered so far.
Any solutions and/or input is welcome. Thanks.
   
Vincent Phuah
Software Technologies Dept.
GTE Laboratories
40 Sylvan Road
Waltham, MA 02254 

bertrand@hub.ucsb.edu (Bertrand Meyer) (01/12/89)

In article <469@grand.UUCP>, Vincent Phuah <vp01@gte.com> wrote:
> 
>               --------------------------
>   I assume it is fair to say that the graphic library in the current
> release has a lot of glitches and doesn't work correctly at times.  

	It is definitely fair to say that. We claim extenuating circumstances,
however, since many of the glitches are due to X Windows (11.1). In
fact, in the process of porting to X 11 release 3, a number of cases
were uncovered in which the Eiffel classes had to be corrected because
they were programmed around X 11.1 bugs which (fortunately) were fixed
in the 11.3. This does not exonerate us totally (some of the glitches
are definitely our responsibility), but anyone who has worked extensively
with X, especially pre-11.3, will agree that this is not the best possible
piece of software to use as a basis for development.

	Release 2.2 of Eiffel is based on X 11.3 and all the
glitches mentioned should have disappeared. A number of improvements will
also be included, in particular with respect to speed (menu display was too
slow) and the possibility of having arbitrary client workstations.
Also, the GOOD utility will work much more nicely.
	
>   Although Eiffel allows calls to external C routines, only basic C type
> parameters can be passed between C and Eiffel. [... Other limitations
> of the Eiffel to C interface]

Making the Eiffel-to-C interface more flexible is another target of our
current efforts.

-- Bertrand Meyer
Interactive Software Engineering
bertrand@eiffel.com