thoth@shark.cis.ufl.edu (Robert Forsman) (09/10/89)
TWO QUESTIONS I'm a novice (started two weeks ago) Xwindows programmer and I've got a question for people familiar with multi window programs. Is there a way to "select" on events from several windows? I know there is a way to block on events from a single window so you don't waste CPU polling for some user to hit a button. The problem is that with several windows you will just have them taking turns on input (i tried it once just to see how it looked). I need a way to say - "If I get an event on any of these windows wake me up and tell me which one." I've written multi socket game daemons before and select does the job perfectly but I have no idea what the analogous call is in X. If anyone has better docs handy could they tell me (all the docs on X I've seen so far suck sewage)? If there is no such call could someone suggest an alternative? SECOND QUESTION. I wrote a "fractal" landscape generator that draws oceans and continents in 3-D into a pixmap and then copies it into the root window background. It looks real cool and doesn't refresh _too_ slow, but when I run something like xconq or even run the "martian" version of the program it can change the colors of the background. I assume that xconq and the "martian" version (the martian landscape just has altered colors and color altitude boundaries) are overwriting the colormap entries. Is there any way to reserve these colors even after the program exits? (I've set the background. Why stick around?) This could be tough because if I change the background again I will have to DEallocate the colors, but that's another problem. I just want to know how to preserve the colors after the generator has copied the pixmap into the root window. If anyone wants the source (the fractals really look neat) I'll have to warn you that it is now set up for screens that are 1152x900 (Sun color monitor) and it will take some fiddling before it looks as pretty on anything else. I haven't documented it, but it is pretty simple (probably has sloppy programming style too). Please respond by mail since this newsgroup is too big for me to read on a regular basis. Thanks ahead of time, and if you have decent docs you are miles ahead of me already. THOTH out -=O=- -- (U. of F., the only place where the CIS department has its own beach :)
rws@EXPO.LCS.MIT.EDU (Bob Scheifler) (09/11/89)
Is there a way to "select" on events from several windows?
What's the problem? If you just have one X connection open, using XNextEvent
or one of its variants should work just fine.
Is there any way to reserve these colors even after the program exits?
Look at what the R3 xsetroot does.klee@gilroy.pa.dec.com (Ken Lee) (09/12/89)
In article <THOTH.89Sep9174745@shark.cis.ufl.edu>, thoth@shark.cis.ufl.edu (Robert Forsman) writes: >I've written multi socket game daemons before and > select does the job perfectly but I have no idea what the analogous > call is in X. If you're talking about selecting events from many windows on 1 server, XSelectEvent and XNextEvent will work fine. If you're talking about many servers, you have to use your operating system's inter-process communication multiplexing facilities. On BSD UNIX, you can use ConnectionNumber() to get file descriptors and select() on those. > If anyone has better docs handy could they tell me (all the docs on > X I've seen so far suck sewage)? If there is no such call could > someone suggest an alternative? Well, the X manuals do assume that you have some background in C programming, raster graphics, and window systems. There are many tutorials on these from other sources. There are also some "intro to X" type books around. Check any good technical bookstore. Ken Lee DEC Western Software Laboratory, Palo Alto, Calif. Internet: klee@decwrl.dec.com uucp: uunet!decwrl!klee
janssen@holmes (Bill Janssen) (09/12/89)
In article <1800@bacchus.dec.com>, klee@gilroy (Ken Lee) writes: >... Check any good technical bookstore. > >Ken Lee >DEC Western Software Laboratory, Palo Alto, Calif. I finally understand what "Check any good technical bookstore" means. It's code for "I live in Palo Alto or Boston". Bill -- Bill Janssen janssen.pa@xerox.com (415) 494-4763 Xerox Palo Alto Research Center 3333 Coyote Hill Road, Palo Alto, California 94304