Re: XForms: overlay &pop-menus &dialogs

Steve Lamont (spl@szechuan.ucsd.edu)
Wed, 13 Jan 99 17:27:48 PST

# To subscribers of the xforms list from spl@szechuan.ucsd.edu (Steve Lamont) :

> I have problems with pop-menus and dialogs, they damage my canvas
> windows and I have to redraw all the time. I am working with 3D images,
> maybe it give you an idea of my PROBLEM. Somebody knows a way to
> manipulate overlays in canvas Windows?? I will really apreciate any
> help.

You're basically doing the right thing.

You might also look at turning on the save under attribute for the
Canvas Window if your X server supports it. This may help (or it may
not).

About the only other suggestion I can make if your redraw rate is too
slow is to copy the contents of the frame buffer to an offscreen
Pixmap before you pop your menus or dialog boxes and then copy the
data back to the frame buffer when you get the Expose event. If you
are moderately clever you can check the Expose event's data structure,
determine which area needs redrawing, and then restore only the area
that got clobbered. This may or may not work, depending upon how the
server manages the frame buffer.

spl

_________________________________________________
To unsubscribe, send the message "unsubscribe" to
xforms-request@bob.usuf2.usuhs.mil or see
http://bob.usuf2.usuhs.mil/mailserv/xforms.html
XForms Home Page: http://bragg.phys.uwm.edu/xforms
List Archive: http://bob.usuf2.usuhs.mil/mailserv/list-archives/