public WhiteboardSessionManager() { if (WhiteboardActivator.getWhiteboardOperationSets() == null) return; Iterator opSets = WhiteboardActivator.getWhiteboardOperationSets().iterator(); while (opSets.hasNext()) { OperationSetWhiteboarding whiteboardOpSet = (OperationSetWhiteboarding) opSets.next(); whiteboardOpSet.addInvitationListener(new InvitationListener()); whiteboardOpSet.addPresenceListener(new PresenceListener()); } }