LEADTOOLS Vector C++ Class Library Help > LEADTOOLS Vector Features > Vector Handles > Vector Handle Events |
Certain events that occur within a vector handle generate calls to the LVectorBase::VectorEventProcCallBack function. This callback function receives information on the calling event in a VECTOREVENT structure received as a parameter. For information on the types of events that the vector handle can generate, refer to the VECTOREVENT structure.
To use the LVectorBase::VectorEventProcCallBack function to receive the vector handle events, you must derive a class from LVectorBase and override the VectorEventProcCallBack member function.
LEADTOOLS also provides the LVectorBase::Event for implementing a user-defined event. This function also lets you group several operations into one event. To do this you must call LVectorBase::Event with the Status member of the pEvent parameter set to VECTOR_EVENT_STATUS_BEFORE. This identifies the beginning of the event. Once all the operations you wish to include have been completed, call LVectorBase::Event with the Status member of the pEvent parameter set to VECTOR_EVENT_STATUS_AFTER. This notifies the toolkit that the operation(s) have been completed successfully.