7/2003
Updated for Project Builder

Read Me About...MyDeviceLoop
date 08/2000

This snippet shows how to write a device loop that	works under System 7 and pre-7.0 systems.  As	described on pages 21-23 and 21-24 of Inside Mac	volume VI, a device loop procedure searches all	active screen devices, calling a drawing procedure whenever it encounters a screen that intersects	the drawing region.  In this app the drawing	region is the app's window bounds and the chosen	drawing procedure simply displays the screen's	colors for every device the window bounds intersect.

Building the Code (CodeWarrior)
This project was built and tested on CodeWarrior 2.1 using CarbonLib 1.1a3.  Since this is a Carbon app, the "Carbon Support" folder of the CarbonSDK should be in the same folder as the CodeWarrior IDE.  If this is not the case, the CarbonLib library will have to be re-added to the project.  In addition, the CarbonLib extension needs to be in the extension folder.  The CarbonSDK (which contains the library and the extension) can be found on Apple's website:  http://developer.apple.com/sdk/

Restrictions (CodeWarrior)
Nearly every sample requires more memory than the 384KB CodeWarrior sets as the default heap size.  If for some reason the memory has been reset to the default (either through converting the project or whatever) the memory should be reset to 1000 - 2000KB (depending on the application).  This can be achieved by going to the projects settings (Edit Menu->C-PPC Settings... under CodeWarrior 2.1) and selecting the "PPC Target" under the "Target" tab.

Other Code Notes
This sample used to be a "non-Carbon" sample, but has been carbonized for demonstration purposes.  The "old" code has been left in (commented out) in order to compare and contrast the Carbon versus non-Carbon APIs.

Known Bugs
No known bugs.

Possible Future Enhancements
None at present.

Other Sources of Reference
Additional sample code can be found at:
http://developer.apple.com/samplecode/
in addition, the Carbon API can be found at:
http://developer.apple.com/techpubs/carbon/carbon.html

Version History
See source for version history.

Author
JM - Apple Developer Technical Support - dts@apple.com