reworked and vastly improved snapping subsystem

app/node/keyframe.h

@@ -26,6 +26,7 @@
 #include <QVariant>
 
 #include "common/rational.h"
+#include "common/timerange.h"
 #include "node/param.h"
 
 namespace olive {
@@ -86,6 +87,14 @@ public:
   const rational& time() const;
   void set_time(const rational& time);
 
+  /**
+   * @brief Dummy function for TimeBasedViewSelectionManager compatibility
+   *
+   * FIXME: Once we upgrade to C++17, we won't need this because we'll be able to check types in
+   * TimeBasedViewSelectionManager's template functions
+   */
+  TimeRange time_range() const { return TimeRange(time_, time_); }
+
   /**
    * @brief The value of this keyframe (i.e. the value to use at this keyframe's time)
    */