+int
+ControlProtocolManager::activate (ControlProtocolInfo& cpi)
+{
+ ControlProtocol* cp;
+
+ cpi.requested = true;
+
+ if ((cp = instantiate (cpi)) == 0) {
+ return -1;
+ }
+
+ /* we split the set_state() and set_active() operations so that
+ protocols that need state to configure themselves (e.g. "What device
+ is connected, or supposed to be connected?") can get it before
+ actually starting any interaction.
+ */
+
+ if (cpi.state) {
+ /* force this by tweaking the internals of the state
+ * XMLNode. Ugh.
+ */
+ cp->set_state (*cpi.state, Stateful::loading_state_version);
+ } else {
+ /* guarantee a call to
+ set_state() whether we have
+ existing state or not
+ */
+ cp->set_state (XMLNode(""), Stateful::loading_state_version);
+ }
+
+ cp->set_active (true);
+
+ return 0;
+}
+
+int
+ControlProtocolManager::deactivate (ControlProtocolInfo& cpi)
+{
+ cpi.requested = false;
+ return teardown (cpi);
+}
+