1 files changed, 66 insertions, 0 deletions
diff --git a/libs/ardour/state_manager.cc b/libs/ardour/state_manager.cc
new file mode 100644
index 0000000000..29a32b96ee
--- /dev/null
+++ b/libs/ardour/state_manager.cc
@@ -0,0 +1,66 @@
+#include <pbd/error.h>
+#include <ardour/state_manager.h>
+
+#include "i18n.h"
+
+using namespace ARDOUR;
+
+StateManager::StateManager ()
+{
+	_current_state_id = 0;
+}
+
+StateManager::~StateManager()
+{
+}
+
+void
+StateManager::drop_all_states ()
+{
+	for (StateMap::iterator i = states.begin(); i != states.end(); ++i) {
+		delete *i;
+	}
+
+	states.clear ();
+
+	save_state (_("cleared history"));
+}
+
+void
+StateManager::use_state (state_id_t id)
+{
+	Change what_changed;
+	state_id_t n;
+	StateMap::iterator i;
+	
+	for (n = 0, i = states.begin(); n < id && i != states.end(); ++n, ++i);
+
+	if (n != id || i == states.end()) {
+		fatal << compose (_("programming error: illegal state ID (%1) passed to "
+				    "StateManager::set_state() (range = 0-%3)"), id,
+				  states.size()-1)
+		      << endmsg;
+		/*NOTREACHED*/
+		return;
+	}
+
+	what_changed = restore_state (**i);
+	_current_state_id = id;
+	send_state_changed (what_changed);
+}
+
+void
+StateManager::save_state (std::string why)
+{
+	if (!should_save_state()) 
+		return;
+
+	states.push_back (state_factory (why));
+	_current_state_id = states.size() - 1;
+}
+
+void
+StateManager::send_state_changed (Change what_changed)
+{
+	StateChanged (what_changed);
+}