timeline: use scroll cooldown when dragging playhead

app/widget/timebased/timebasedwidget.cpp

@@ -46,6 +46,7 @@ TimeBasedWidget::TimeBasedWidget(bool ruler_text_visible, bool ruler_cache_statu
   ruler_ = new TimeRuler(ruler_text_visible, ruler_cache_status_visible, this);
   ConnectTimelineView(ruler_, true);
   ruler()->SetSnapService(this);
+  connect(ruler(), &TimeRuler::DragReleased, this, static_cast<void(TimeBasedWidget::*)()>(&TimeBasedWidget::StopCatchUpScrollTimer));
 
   scrollbar_ = new ResizableTimelineScrollBar(Qt::Horizontal, this);
   connect(scrollbar_, &ResizableScrollBar::ResizeBegan, this, &TimeBasedWidget::ScrollBarResizeBegan);
@@ -348,7 +349,7 @@ void TimeBasedWidget::SetTime(const rational &time)
 {
   if (UserIsDraggingPlayhead()) {
     // If the user is dragging the playhead, we will simply nudge over and not use autoscroll rules.
-    QMetaObject::invokeMethod(this, "CatchUpScrollToPlayhead", Qt::QueuedConnection);
+    SetCatchUpScrollValue(qRound(TimeToScene(time)) - scrollbar_->value());
   } else {
     // Otherwise, assume we jumped to this out of nowhere and must now autoscroll
     switch (static_cast<AutoScroll::Method>(OLIVE_CONFIG("Autoscroll").toInt())) {

app/widget/timebased/timebasedwidget.h

@@ -121,9 +121,6 @@ public slots:
 
   void DeleteSelected();
 
-protected slots:
-  void SetTimeAndSignal(const rational& t);
-
 protected:
   ResizableTimelineScrollBar* scrollbar() const;
 
@@ -153,10 +150,6 @@ protected:
   void SetCatchUpScrollValue(QScrollBar *b, int v, int maximum);
   void SetCatchUpScrollValue(int v);
   void StopCatchUpScrollTimer(QScrollBar *b);
-  void StopCatchUpScrollTimer()
-  {
-    StopCatchUpScrollTimer(scrollbar_);
-  }
 
   virtual const QVector<Block*> *GetSnapBlocks() const { return nullptr; }
   virtual const QVector<KeyframeViewInputConnection*> *GetSnapKeyframes() const { return nullptr; }
@@ -177,6 +170,13 @@ protected slots:
 
   static void PageScrollInternal(QScrollBar* bar, int maximum, int screen_position, bool whole_page_scroll);
 
+  void SetTimeAndSignal(const olive::rational& t);
+
+  void StopCatchUpScrollTimer()
+  {
+    StopCatchUpScrollTimer(scrollbar_);
+  }
+
 signals:
   void TimeChanged(const rational&);