Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!ucbvax!ucdavis!csusac!unify!magpie!grp From: grp@unify.uucp (Greg Pasquariello) Newsgroups: comp.windows.x Subject: Re: OpenLook: drawing in bulletin boards Message-ID: Date: 23 Jul 90 15:56:17 GMT References: <836@phcisa.UUCP> Sender: news@Unify.Com (news admin) Reply-To: grp@unify.com Organization: Unify Corporation, Sacramento, California Lines: 44 In-Reply-To: finus@phcisa.UUCP's message of 20 Jul 90 09:33:58 GMT In article <836@phcisa.UUCP> finus@phcisa.UUCP (Finus van Cadsand) writes: > > Path: unify!csusac!csuchico.edu!petunia!usc!snorkelwacker!bloom-beacon!eru!luth!sunic!mcsun!hp4nl!phcisa!finus > From: finus@phcisa.UUCP (Finus van Cadsand) > Newsgroups: comp.windows.x > Keywords: bulletin board,drawing > Date: 20 Jul 90 09:33:58 GMT > Lines: 17 > > Using the bulletin board widget of Open Look I represent some widgets at > particular coordinates. I want to draw lines or arrows between some of > these widgets. But somehow what is drawn to the bulletin board never > appears at the screen, not even after the bulletin board has been realised. > > Investigation shows that for the bulletin board widget no expose procedure > is defined, which gives an indication why nothing appears. > > Now I have two questions: > > 1. is my line of reasoning okay ? Yes, without the expose procdure, no redrawing will occur. > > 2. maybe somebody knows a workaround ? like a specialization of the > bulletin board that handles expose events ? please comment. This is one way to go about it, and IMO probably the best way. Simply sublcass the widget and provide an expose procedure. Note that you will also have to provide a foreground resource (and a GC) because the bulletin board does not provide one for you. Another way to go about this, would be to use the stub widget to provide the drawing capabilities. Basically you can hook your own routines into the stub's methods. Then, create a hierarchy where the bulletin board is the base, and the stub and all your other widgets are siblings. If you map your widgets on top of the stub, you will get the desired effect. > > --------------------------------------------------------------------------------Finus van Cadsand, ORIGIN-MW, Eindhoven, the Netherlands > email: finus@ait.philips.nl (will be changed to: finus@ait.origin.nl) -- -Greg Pasquariello grp@unify.com