Immediate Children of the Root View Are Special

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.

Immediate Children of the Root View Are Special (11/17/94)

Q: In trying to make a better "modal" dialog, I am attempting to create a child of the root view that is full-screen and transparent. When I do this, the other views always disappear, and reappear when the window is closed. Why?

A: Immediate children of the root view are handled differently by the view system. They cannot be transparent, and will be filled white unless otherwise specified. Also, unlike other views in Newton 2.0 OS, their borders are considered part of the view and so taps in the borders will be sent to them.

This was done deliberately to discourage tap-stealing and other unusual view interaction. Each top level view (usually one application) is intended to stand on its own and operate independently of other applications.

So-called "application modal" dialogs can and should be implemented using the technique you describe with the transparent window as a child of the application's base view.

You can make system modal dialogs with the view methods FilterDialog and ModalDialog. (See the Q&A "FilterDialog and ModalDialog Limitations" for important information on those methods.)