Inside Macintosh: Mac OS 8 Toolbox Reference /

Chapter 2 - Control Manager Reference / Control Manager Functions

Manipulating Controls /

SendControlMessage

NEW WITH THE APPEARANCE MANAGER

Sends a message to a control definition function.

pascal SInt32 SendControlMessage (
                     ControlHandle inControl,
                     SInt16 inMessage,
                     SInt32 inParam);

inControl

On input, a handle to the control to which you are sending a low-level message.

inMessage

A bit field representing the message(s) you wish to send; see "Messages".

inParam

The message-dependent data passed in the param parameter of the control definition function.

function result

Returns a signed 32-bit integer which contains varying data depending upon the message sent; see "Messages".

DISCUSSION

Your application does not normally need to call the SendControlMessage function. If you have a special need to call a control definition function directly, call SendControlMessage to access and manipulate the control's attributes.

Before calling SendControlMessage, you should determine whether the control supports the specific message you wish to send by calling GetControlFeatures and examining the feature bit field returned. If there are no feature bits returned that correspond to the message you wish to send (for messages 0 through 12), you can assume that all system controls support that message.

SEE ALSO

MyControlDefProc.

"Appearance Manager Gestalt Selector Constants".