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);

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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:

hIGear does not reference a valid ImageGear handle.
nCallbackID is not one of the predefined callback types.
lpfnCallback is not NULL or a valid address.