Move the code that scrolls during scrub out of Scrubbing.cpp

src/Project.cpp

@@ -933,14 +933,18 @@ AudacityProject::AudacityProject(wxWindow * parent, wxWindowID id,
    mCursorOverlay = std::make_unique<EditCursorOverlay>(this);
 
 #ifdef EXPERIMENTAL_SCRUBBING_BASIC
-   // This must follow construction of *mIndicatorOverlay, because it must
-   // attach its timer event handler later (so that its handler is invoked
-   // earlier)
    mScrubOverlay = std::make_unique<ScrubbingOverlay>(this);
    mScrubber = std::make_unique<Scrubber>(this);
 #endif
 
-   // This must follow construction of *mScrubOverlay, because it must
+   // More order dependencies here...
+   // This must follow construction of *mIndicatorOverlay, because it must
+   // attach its timer event handler later (so that its handler is invoked
+   // earlier)
+   mPlaybackScroller = std::make_unique<PlaybackScroller>(this);
+
+   // This must follow construction of *mPlaybackScroller,
+   // because it must
    // attach its timer event handler later (so that its handler is invoked
    // earlier)
    this->Connect(EVT_TRACK_PANEL_TIMER,
@@ -5315,3 +5319,46 @@ int AudacityProject::GetEstimatedRecordingMinsLeftOnDisk() {
    int iRecMins = (int)(dRecTime / 60.0);
    return iRecMins;
 }
+
+AudacityProject::PlaybackScroller::PlaybackScroller(AudacityProject *project)
+: mProject(project)
+{
+   mProject->Connect(EVT_TRACK_PANEL_TIMER,
+                     wxCommandEventHandler(PlaybackScroller::OnTimer),
+                     NULL,
+                     this);
+}
+
+AudacityProject::PlaybackScroller::~PlaybackScroller()
+{
+   mProject->Disconnect(EVT_TRACK_PANEL_TIMER,
+                        wxCommandEventHandler(PlaybackScroller::OnTimer),
+                        NULL,
+                        this);
+}
+
+void AudacityProject::PlaybackScroller::OnTimer(wxCommandEvent &event)
+{
+   // Let other listeners get the notification
+   event.Skip();
+
+#ifdef EXPERIMENTAL_SCRUBBING_SMOOTH_SCROLL
+   if (mActive && mProject->IsAudioActive())
+   {
+      // Pan the view, so that we center the play indicator.
+
+      ViewInfo &viewInfo = mProject->GetViewInfo();
+      TrackPanel *const trackPanel = mProject->GetTrackPanel();
+      const int posX = viewInfo.TimeToPosition(viewInfo.mRecentStreamTime);
+      int width;
+      trackPanel->GetTracksUsableArea(&width, NULL);
+      const int deltaX = posX - width / 2;
+      viewInfo.h =
+      viewInfo.OffsetTimeByPixels(viewInfo.h, deltaX, true);
+      if (!viewInfo.bScrollBeyondZero)
+         // Can't scroll too far left
+         viewInfo.h = std::max(0.0, viewInfo.h);
+      trackPanel->Refresh(false);
+   }
+#endif
+}

src/Project.h

@@ -720,6 +720,28 @@ public:
    const Scrubber &GetScrubber() const { return *mScrubber; }
 #endif
 
+   class PlaybackScroller final : public wxEvtHandler
+   {
+   public:
+      explicit PlaybackScroller(AudacityProject *project);
+      ~PlaybackScroller();
+
+      void Activate(bool active)
+      {
+         mActive = active;
+      }
+
+   private:
+      void OnTimer(wxCommandEvent &event);
+
+      AudacityProject *mProject;
+      bool mActive { false };
+   };
+   std::unique_ptr<PlaybackScroller> mPlaybackScroller;
+
+public:
+   PlaybackScroller &GetPlaybackScroller() { return *mPlaybackScroller; }
+
    DECLARE_EVENT_TABLE()
 };
 

src/tracks/ui/Scrubbing.cpp

@@ -200,7 +200,7 @@ void Scrubber::MarkScrubStart(
    // needed for the decision to start scrubbing later when handling
    // drag events.
 #ifdef EXPERIMENTAL_SCRUBBING_SMOOTH_SCROLL
-   mSmoothScrollingScrub = smoothScrolling;
+   SetScrollScrubbing (smoothScrolling);
 #endif
    mAlwaysSeeking = alwaysSeeking;
    mScrubStartPosition = xx;
@@ -356,25 +356,6 @@ void Scrubber::ContinueScrubbing()
       if (mScrubSpeedDisplayCountdown > 0)
          --mScrubSpeedDisplayCountdown;
    }
-
-#ifdef EXPERIMENTAL_SCRUBBING_SMOOTH_SCROLL
-   if (mSmoothScrollingScrub) {
-      // Pan the view, so that we center the play indicator.
-
-      ViewInfo &viewInfo = mProject->GetViewInfo();
-      TrackPanel *const trackPanel = mProject->GetTrackPanel();
-      const int posX = viewInfo.TimeToPosition(viewInfo.mRecentStreamTime);
-      int width;
-      trackPanel->GetTracksUsableArea(&width, NULL);
-      const int deltaX = posX - width / 2;
-      viewInfo.h =
-         viewInfo.OffsetTimeByPixels(viewInfo.h, deltaX, true);
-      if (!viewInfo.bScrollBeyondZero)
-         // Can't scroll too far left
-         viewInfo.h = std::max(0.0, viewInfo.h);
-      trackPanel->Refresh(false);
-   }
-#endif
 }
 
 void Scrubber::StopScrubbing()
@@ -382,7 +363,7 @@ void Scrubber::StopScrubbing()
    UncheckAllMenuItems();
 
    mScrubStartPosition = -1;
-   mSmoothScrollingScrub = false;
+   SetScrollScrubbing (false);
 
    if (!IsScrubbing())
    {
@@ -393,6 +374,12 @@ void Scrubber::StopScrubbing()
    }
 }
 
+void Scrubber::SetScrollScrubbing(bool scrollScrubbing)
+{
+   mSmoothScrollingScrub = scrollScrubbing;
+   mProject->GetPlaybackScroller().Activate(scrollScrubbing);
+}
+
 bool Scrubber::IsScrubbing() const
 {
    if (mScrubToken <= 0)
@@ -403,6 +390,7 @@ bool Scrubber::IsScrubbing() const
       const_cast<Scrubber&>(*this).mScrubToken = -1;
       const_cast<Scrubber&>(*this).mScrubStartPosition = -1;
 #ifdef EXPERIMENTAL_SCRUBBING_SMOOTH_SCROLL
+      // Don't call SetScrollScrubbing
       const_cast<Scrubber&>(*this).mSmoothScrollingScrub = false;
 #endif
       return false;
@@ -557,7 +545,6 @@ void ScrubbingOverlay::Draw
    dc.DrawText(mLastScrubSpeedText, mLastScrubRect.GetX(), mLastScrubRect.GetY());
 }
 
-
 void ScrubbingOverlay::OnTimer(wxCommandEvent &event)
 {
    // Let other listeners get the notification
@@ -666,7 +653,7 @@ void Scrubber::DoScrub(bool scroll, bool seek)
       MarkScrubStart(xx, scroll, seek);
    }
    else if(!match) {
-      mSmoothScrollingScrub = scroll;
+      SetScrollScrubbing(scroll);
       mAlwaysSeeking = seek;
       UncheckAllMenuItems();
       CheckMenuItem();

src/tracks/ui/Scrubbing.h

@@ -54,8 +54,11 @@ public:
    bool HasStartedScrubbing() const
    { return GetScrubStartPosition() >= 0; }
    bool IsScrubbing() const;
+
    bool IsScrollScrubbing() const // If true, implies HasStartedScrubbing()
    { return mSmoothScrollingScrub; }
+   void SetScrollScrubbing(bool scrollScrubbing);
+
    bool IsAlwaysSeeking() const
    { return mAlwaysSeeking; }