ImageGear for C and C++ on Linux v20.0 - Updated
ART_callback_register
API Reference Guide > ART Component API Reference > ART Component Functions Reference > Callback Register Functions > ART_callback_register

This function registers an ART callback function (see the callback functions at the end of this reference in the section ART Component Callback Functions Reference).

Declaration:

 
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AT_ERRCOUNT ART_callback_register( 
        HIGEAR hIGear,
        AT_MODE nCallbackID, 
        LPFNIG_ART_CALLBACKFUNC lpfnCallback, 
        LPVOID lpPrivate
);

Arguments:

Name Type Description
hIGear HIGEAR HIGEAR handle to the image.
nCallbackID AT_MODE An ART-defined constant of type AT_MODE that tells which type of callback is being registered.
lpfnCallback LPFNIG_ART_CALLBACKFUNC A far pointer to your callback function to register.
lpPrivate LPVOID A far pointer to private data (passed to callback function).

Return Value:

Returns the number of ImageGear errors that occurred during the function call.

Supported Raster Image Formats:

All pixel formats supported by ImageGear for C and C++.

Example:

 
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HIGEAR hIGear; /* HIGEAR handle of image */
AT_ERRCOUNT nErrcount; /* Tally of IG errors on  */
             /* the stack    */
VOID privateData; /* Any private data that you */
/* would like to pass to the */
/* callback   */
nErrcount = ART_callback_register(hIGear, 
ART_CALLBACK_CREATE_MODIFY ,myCallbackFunc, (LPVOID) 
&privateData);

Remarks:

To unregister a function, pass NULL to the lpfnCallback parameter.

nCallbackID is a predefined value that identifies the type of callback to register. The predefined constants for this variable reside in ARTAPI.H and begin with the prefix ART_CALLBACK_. Only one callback of each type may be registered at the same time.

An error is set if any of the following conditions are met:

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