EZ_AddItemCallBack(3)           EZWGL Functions          EZ_AddItemCallBack(3)

       EZ_AddItemCallBack,EZ_RemoveItemCallBack, EZ_RemoveAllItemCallBacks  -
       register/remove callbacks associated to a display item

       #include <EZ.h>

       void EZ_AddItemCallBack( EZ_Item *item,
            int which, EZ_CallBack callback, void *clientdata, int location)
       void EZ_RemoveItemCallBack( EZ_Item *item,
            int which, EZ_CallBack callback, void *clientdata)

       void EZ_RemoveAllItemCallBacks( EZ_Item *item, int which)

       item  Specifies a display item.

       callback  Specifies a callback.

       clientdata  Specifies an clientdata to be passed to the callback.

       which  Specifies a callback list.

       location  Specifies when the callback is to be called relative to other
       previously callbacks.

       An callback is a procedure of the following prototype:

           void (* callback)(void *object, void *data)

       EZ_AddItemCallBack registers a callback to a item.  There are two
       callback lists associated to a item: an EZ_CALLBACK list and an
       EZ_DESTROY_CALLBACK list.  Normal callbacks are called when a double
       Button1 click occurs on a item.  Destroy callbacks are invoked at the
       time a item is destroyed. If location is 0, the callback will be put in
       front of all previously registered callbacks. If location is 1, the
       callback will be inserted at the end of all previousely registered

       EZ_RemoveItemCallBack deletes a callback from the specified callback
       list. The specified callback will be deleted only if both the procedure
       and the client data match.

       EZ_RemoveAllCallBacks deletes all callbacks from the specified callback

       EZ_CreateItem(3), EZ_ConfigureItem(3), EZ_SetItemClientData(3)

EZWGL                                                    EZ_AddItemCallBack(3)