mershon@heron.cis.ohio-state.edu (Stuart Mershon) (02/18/89)
I am a novice X11R3 programmer looking for some help in dealing with the scrollbar widget. I am trying to use the callback procedure specified by XtNscrollProc to nudge the thumb a little bit one way or another, depending upon which mouse button was pressed. In order to do this, I have tried to use XtGetValues, which doesn't want to cooperate. So, I stepped back to the following: float top,shown; top = 0.5; shown = -1.0; XtScrollBarSetThumb(scrl[call_id],top,shown); XtSetArg( arg[0], XtNtop, &top ); XtGetValues( scrl[call_id], arg, ONE ); Even though my scrollbar shows the thumb in the proper position, top always comes back from XtGetValues with a zero value. Can anyone out there show me the error of my ways. Any help is greatly appreciated. Thanks, ... Jeb mershon@cis.ohio-state.edu
klee@daisy.UUCP (Ken Lee) (02/18/89)
In article <35812@tut.cis.ohio-state.edu> <mershon@cis.ohio-state.edu> writes:
=> float top,shown;
=> XtSetArg( arg[0], XtNtop, &top );
=> XtGetValues( scrl[call_id], arg, ONE );
=>
=> Even though my scrollbar shows the thumb in the proper position, top
=>always comes back from XtGetValues with a zero value.
Funny, this code works fine for me (X11R3, Sun 386i, SunOS 4.0.1),
assuming scrl[call_id] is a valid widget ID. Does your machine have a
problem with pointers to floats?
Ken Lee
--
klee@daisy.uucp
Daisy Systems Corp., Interactive Graphics Tools Dept.