How to Prevent an Application From Opening
One of the Newton 2.x OS Q&As
Copyright © 1997 Newton, Inc. All Rights Reserved. Newton, Newton Technology, Newton Works, the Newton, Inc. logo, the Newton Technology logo, the Light Bulb logo and MessagePad are trademarks of Newton, Inc. and may be registered in the U.S.A. and other countries. Windows is a registered trademark of Microsoft Corp. All other trademarks and company names are the intellectual property of their respective owners.
For the most recent version of the Q&As on the World Wide Web, check the URL: http://www.newton-inc.com/dev/techinfo/qa/qa.htm
If you've copied this file locally,click here to go to the main Newton Q&A page.
This document was exported on 7/23/97.
How to Prevent an Application From Opening (6/9/94)
- Q: I do not want my application to open sometimes, for example because the screen size is too small, or because the Newton OS version is wrong. What's the best way to prevent it?
A: Check for whatever constraints or requirements you need early, if not in the installScript, then in the viewSetupFormScript for the application's base view. In your case, you can do some math on the frame returned from GetAppParams to see if the screen is large enough to support your application.
If you do not want the application to open, do the following:
• Call Notify to tell the user why your application cannot run.
• Set the base view's viewBounds so it does not appear, use
RelBounds(-10, -10, 0, 0) so the view will be off-screen.
• Possibly set (and check) a flag so expensive startup things do not happen.
• Possibly set the base view's viewChildren and stepChildren slots to NIL.
• call AddDeferredSend(self, 'Close, nil) to close the view.