Inside Macintosh: Mac OS 8 Toolbox Reference /

Chapter 2 - Control Manager Reference / Control Manager Functions

Defining Your Own Action Functions /

MyIndicatorActionProc

NOT RECOMMENDED WITH THE APPEARANCE MANAGER

When the Appearance Manager is available, you should use MyActionProc to define actions to be performed in response to a mouse-down event in an indicator of a control that supports live feedback.

You should only use MyIndicatorActionProc if the control does not support live feedback.