Turns the monitoring of selection changes on/off.

    GSErrCode  ACAPI_Notify_CatchSelectionChange (
        APISelectionChangeHandlerProc*     handlerProc



[in] The callback procedure to call when notifications are sent out on changes in the selection. Specifying nullptr here means you don’t need the notifications any more.


Return Values

The function completed successfully.

For other common errors see the list of error codes.



This function is used to register/unregister an add-on which wants to monitor the changes in selection. You do not have to call ACAPI_KeepInMemory afterwards, as the API ensures that add-ons with installed notification handlers won’t be unloaded.
After registration your add-on’s handlerProc you will be called when the selection changes.



// -----------------------------------------------------------------------------
// Selection change handler function
// -----------------------------------------------------------------------------
static GSErrCode __ACENV_CALL    SelectionChangeHandler (const API_Neig *selElemNeig)

    char    msgStr[256];

    if (selElemNeig->neigID != APINeig_None) {
        sprintf (msgStr, "Last selected element: NeigID %d; index: %d, inIndex: %d",
                 selElemNeig->neigID, selElemNeig->index, selElemNeig->inIndex);
        ACAPI_WriteReport (msgStr, false);
    } else
        ACAPI_WriteReport ("All elements deselected", false);

    return NoError;
}   // SelectionChangeHandler

// -----------------------------------------------------------------------------
// Called after the Add-On has been loaded into memory
// -----------------------------------------------------------------------------
GSErrCode    __ACENV_CALL    Initialize (void)

    // catch changes in the selection
    GSErrCode err = ACAPI_Notify_CatchSelectionChange (SelectionChangeHandler);

    return err;
}   // Initialize



Version: API 4.1 or later
Header: ACAPinc.h


See Also

ACAPI_KeepInMemory, APISelectionChangeHandlerProc,
Notification Manager, API Functions