rzmul3@tuvie.UUCP (Uni Leoben) (04/02/91)
I am working on a Grafiklibrary under XView.
We need to have a special graphics library, because we try to
port lots of older softwarepackages under VMS with special
graphics terminals and we don`t want to change the graphical parts of
these packages.
I am trying to use the scrollbars attached to a canvas as a zooming
and position feature into a display list which works with a NDC
coodinate system. The canvas paint window stays the same size as the
canvas and has nothing to do with the data portion displayed.
When setting the scrollbar parameters to the
equivilent portions of my NDC-Space I get a lot of very obscure
effects:
1) Canvas paint window starts somewhere below canvas startpoint
or even outside the canvas.
(I can monitor this effect by logging of pointer move events)
2) If I resize the frame window (and with it the canvas) I get
a bus error inside the canvas package.
(in routine canvas_set_paint_window_size)
Has anybody out there a solution to my problem?
I want to use scrollbars in the canvas, but they don't have to do
anything with sizes or positions of canvas subwindows.
Thanks
(Guenther Stossl, Mining University LEOBEN, Austria)