From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=0.7 required=5.0 tests=BAYES_00,INVALID_DATE, MSGID_SHORT,REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!esosun!hyland From: hyland@esosun.UUCP (Steve Hyland) Newsgroups: comp.windows.x,comp.lang.ada Subject: Re: X and Ada? Message-ID: <64@kvasir.esosun.UUCP> Date: Thu, 10-Sep-87 18:22:25 EDT Article-I.D.: kvasir.64 Posted: Thu Sep 10 18:22:25 1987 Date-Received: Sat, 12-Sep-87 11:22:02 EDT References: <249@sandia.UUCP> Reply-To: hyland@kvasir.UUCP (Steve Hyland) Distribution: na Organization: SAIC, San Diego Xref: mnetor comp.windows.x:1401 comp.lang.ada:672 List-Id: In article <249@sandia.UUCP> pjatter@sandia.UUCP (Paul Attermeier) writes: >Is X and Ada a practical combination? Yes. We are currently using a subset Ada binding to X. More pertinent: >>From what little I've seen of the X toolkits, it appears that >X makes 'callbacks' to the application program. If X is in C >(which would be acceptable in our 'Ada' system) and the application >is in Ada, it looks like we still have the same problem. Yes, the current X toolkit allows the user to include a call-back routine in the argument list. Since this would violate the spirit of Ada, we will not allow this. We have a similar problem in the intrinsics, with the use of event handlers in widgets. The answer ? Its not completely obvious to me at this point. More to the point, however; the toolkit is a SUGGESTED set of sample widgets. How they are implemented is very specific to C. How they are implemented in our version will be very specific to Ada. In other words, to the interface user, the widgets will appear the same. To the application programmer, C widgets and Ada widgets will be different from each other. And for the widget programmer, as with the C version, the toolkit will be a template for creating other widgets. Some of the ways in which we are considering implementing widgets: Tasking : seems to be more in the spirit of Widgets-As-Objects, Procedure Calls: that is, you create a widget with a procedure call, and must handle the events that occur in that widget. We are leaning toward widgets as task types, since this seems (at least, intuitively) the correct approach. My only concern is overhead associated with lots of tasks. Anyone else have any thoughts ? >Do we need to wait for an Ada implementation of X? Will such a thing >be available in my lifetime? Am I missing a more obvious solution? No, you do not need to wait if you are in a hurry. A basic binding can be hacked out fairly quickly. On the other hand, we have a STARS contract to build the Ada binding (which will become public domain, I believe) to X and the X Toolkit. The final versions of these, to be deliverable in about a year, will be completely written in Ada. An interim version, which binds to the C version of X11 will be available in about 6 months. >Paul Attermeier >uucp: ...{ucbvax | gatech}!unmvax!sandia!pjatter >arpanet: pjatter@sandia-2 Steve Hyland SAIC