timeruler: ported common functions to timelinescaledobject

Removed code that was largely duplicated.

app/widget/timeruler/timeruler.h

@@ -27,19 +27,15 @@
 #include "common/rational.h"
 #include "common/timerange.h"
 #include "timeline/timelinepoints.h"
+#include "widget/timelinewidget/timelinescaledobject.h"
 #include "widget/timelinewidget/view/timelineplayhead.h"
 
-class TimeRuler : public QWidget
+class TimeRuler : public QWidget, public TimelineScaledObject
 {
   Q_OBJECT
 public:
   TimeRuler(bool text_visible = true, bool cache_status_visible = false, QWidget* parent = nullptr);
 
-  const double& GetScale();
-  void SetScale(const double& d);
-
-  void SetTimebase(const rational& r);
-
   void SetCenteredText(bool c);
 
   void ConnectTimelinePoints(TimelinePoints* points);
@@ -63,6 +59,10 @@ protected:
   virtual void mousePressEvent(QMouseEvent *event) override;
   virtual void mouseMoveEvent(QMouseEvent *event) override;
 
+  virtual void TimebaseChangedEvent(const rational& tb) override;
+
+  virtual void ScaleChangedEvent(const double&);
+
 signals:
   /**
    * @brief Signal emitted whenever the time changes on this ruler, either by user or programatically
@@ -100,12 +100,6 @@ private:
 
   bool centered_text_;
 
-  double scale_;
-
-  rational timebase_;
-
-  double timebase_dbl_;
-
   double timebase_flipped_dbl_;
 
   int64_t time_;