home *** CD-ROM | disk | FTP | other *** search
/ Developer CD Series 1997 January: Mac OS SDK / Dev.CD Jan 97 SDK2.toast / Development Kits (Disc 2) / OpenDoc Development Framework / ODF-Interest Archive / July 96 / Re Scroll notification < prev    next >
Encoding:
Internet Message Format  |  1996-08-01  |  1.1 KB  |  [TEXT/ttxt]
  1. Subject:     Re: Scroll notification
  2. Sent:        7/29/96 4:05 PM
  3. Received:    7/29/96 4:11 PM
  4. From:        Kirk Swenson, kswenson@keypress.com
  5. Reply-To:    ODF Interest, ODF-Interest@CILabs.ORG
  6. To:          OpenDoc Development Framework Discussion List, ODF-Interest@CILabs.
  7.  
  8. >My part has an offscreen bitmap which I keep in synch with the onscreen
  9. >view. Therefore, when the user scrolls, both the onscreen view and my
  10. >offscreen bitmap are notified of the scroll. My problem is that the view
  11. >gets the notification first, before my offscreen. This creates a problem
  12. >because my offscreen doesn't get to draw before the onscreen view.
  13. >Therefore the view draws nothing (it gets it from the offscreen) in the
  14. >newly scrolled into view region.
  15.  
  16. How about making your offscreen bitmap a notifier?  Then the view
  17. (receiver) can be hooked to the offscreen bitmap (notifier), so that the
  18. notification travels: scroll bar --> offscreen bitmap --> view.
  19. Conceptually, the view should update (be notified) whenever the offscreen
  20. bitmap changes, whether or not scrolling is involved.
  21.  
  22. Kirk Swenson
  23. Senior Software Engineer
  24. Key Curriculum Press
  25. kswenson@keypress.com
  26.  
  27.  
  28.