[thin_restore] Add a progress monitor

base/progress_monitor.h

@@ -0,0 +1,25 @@
+#ifndef BASE_PROGRESS_MONITOR_H
+#define BASE_PROGRESS_MONITOR_H
+
+#include <boost/shared_ptr.hpp>
+#include <string>
+
+//----------------------------------------------------------------
+
+namespace base {
+	class progress_monitor {
+	public:
+		typedef boost::shared_ptr<progress_monitor> ptr;
+
+		virtual ~progress_monitor() {}
+
+		virtual void update_percent(unsigned) = 0;
+	};
+
+	progress_monitor::ptr create_progress_bar(std::string const &title);
+	progress_monitor::ptr create_quiet_progress_monitor();
+}
+
+//----------------------------------------------------------------
+
+#endif