Double click on Record button pins record head right, not center

src/Project.cpp

@@ -257,6 +257,9 @@ void ScrollBar::SetScrollbar(int position, int thumbSize,
 {
    // Mitigate flashing of scrollbars by refreshing only when something really changes.
 
+   // PRL:  This may have been made unnecessary by other fixes for flashing, see
+   // commit ac05b190bee7dd0000bce56edb0e5e26185c972f
+
    auto changed =
       position != GetThumbPosition() ||
       thumbSize != GetThumbSize() ||
@@ -5366,7 +5369,7 @@ void AudacityProject::PlaybackScroller::OnTimer(wxCommandEvent &event)
    // Let other listeners get the notification
    event.Skip();
 
-   if (mActive && mProject->IsAudioActive())
+   if (mMode != Mode::Off && mProject->IsAudioActive())
    {
       // Pan the view, so that we center the play indicator.
 
@@ -5375,9 +5378,19 @@ void AudacityProject::PlaybackScroller::OnTimer(wxCommandEvent &event)
       const int posX = viewInfo.TimeToPosition(viewInfo.mRecentStreamTime);
       int width;
       trackPanel->GetTracksUsableArea(&width, NULL);
-      const int deltaX = posX - width / 2;
+      int deltaX;
+      switch (mMode)
+      {
+         default:
+            wxASSERT(false);
+            /* fallthru */
+         case Mode::Centered:
+            deltaX = posX - width / 2;    break;
+         case Mode::Right:
+            deltaX = posX - width;        break;
+      }
       viewInfo.h =
-      viewInfo.OffsetTimeByPixels(viewInfo.h, deltaX, true);
+         viewInfo.OffsetTimeByPixels(viewInfo.h, deltaX, true);
       if (!viewInfo.bScrollBeyondZero)
          // Can't scroll too far left
          viewInfo.h = std::max(0.0, viewInfo.h);

src/Project.h

@@ -728,16 +728,23 @@ public:
       explicit PlaybackScroller(AudacityProject *project);
       ~PlaybackScroller();
 
-      void Activate(bool active)
+      enum class Mode {
+         Off,
+         Centered,
+         Right,
+      };
+
+      Mode GetMode() const { return mMode; }
+      void Activate(Mode mode)
       {
-         mActive = active;
+         mMode = mode;
       }
 
    private:
       void OnTimer(wxCommandEvent &event);
 
       AudacityProject *mProject;
-      bool mActive { false };
+      Mode mMode { Mode::Off };
    };
    std::unique_ptr<PlaybackScroller> mPlaybackScroller;
 

src/toolbars/ControlToolBar.cpp

@@ -751,7 +751,8 @@ void ControlToolBar::OnPlay(wxCommandEvent & WXUNUSED(evt))
    auto p = GetActiveProject();
 
    if (doubleClicked)
-      p->GetPlaybackScroller().Activate(true);
+      p->GetPlaybackScroller().Activate
+         (AudacityProject::PlaybackScroller::Mode::Centered);
    else {
       if (!CanStopAudioStream())
          return;
@@ -794,7 +795,8 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
    AudacityProject *project = GetActiveProject();
 
    if(project) {
-      project->GetPlaybackScroller().Activate(false);
+      project->GetPlaybackScroller().Activate
+         (AudacityProject::PlaybackScroller::Mode::Off);
       // Let scrubbing code do some appearance change
       project->GetScrubber().StopScrubbing();
    }
@@ -855,7 +857,8 @@ void ControlToolBar::OnRecord(wxCommandEvent &evt)
    mRecord->ClearDoubleClicked();
 
    if (doubleClicked) {
-      GetActiveProject()->GetPlaybackScroller().Activate(true);
+      GetActiveProject()->GetPlaybackScroller().Activate
+         (AudacityProject::PlaybackScroller::Mode::Right);
       return;
    }
 

src/toolbars/TranscriptionToolBar.cpp

@@ -480,7 +480,8 @@ void TranscriptionToolBar::OnPlaySpeed(wxCommandEvent & WXUNUSED(event))
    button->ClearDoubleClicked();
 
    if (doubleClicked) {
-      GetActiveProject()->GetPlaybackScroller().Activate(true);
+      GetActiveProject()->GetPlaybackScroller().Activate
+         (AudacityProject::PlaybackScroller::Mode::Centered);
 
       // Pop up the button
       SetButton(false, button);

src/tracks/ui/PlayIndicatorOverlay.cpp

@@ -165,9 +165,12 @@ void PlayIndicatorOverlay::OnTimer(wxCommandEvent &event)
 
       // BG: Scroll screen if option is set
       // msmeyer: But only if not playing looped or in one-second mode
+      // PRL: and not scrolling with play/record head fixed right
       if (viewInfo.bUpdateTrackIndicator &&
           mProject->mLastPlayMode != PlayMode::loopedPlay &&
           mProject->mLastPlayMode != PlayMode::oneSecondPlay &&
+          mProject->GetPlaybackScroller().GetMode() !=
+             AudacityProject::PlaybackScroller::Mode::Right &&
          playPos >= 0 &&
          !onScreen &&
          !gAudioIO->IsPaused())

src/tracks/ui/Scrubbing.cpp

@@ -331,7 +331,9 @@ bool Scrubber::MaybeStartScrubbing(wxCoord xx)
          mScrubStartClockTimeMillis = ::wxGetLocalTimeMillis();
 
       if (IsScrubbing()) {
-         mProject->GetPlaybackScroller().Activate(mSmoothScrollingScrub);
+         using Mode = AudacityProject::PlaybackScroller::Mode;
+         mProject->GetPlaybackScroller().Activate
+            (mSmoothScrollingScrub ? Mode::Centered : Mode::Off);
          mScrubHasFocus = true;
          mLastScrubPosition = xx;
 
@@ -423,7 +425,8 @@ void Scrubber::StopScrubbing()
    UncheckAllMenuItems();
 
    mScrubStartPosition = -1;
-   mProject->GetPlaybackScroller().Activate(false);
+   mProject->GetPlaybackScroller().Activate
+      (AudacityProject::PlaybackScroller::Mode::Off);
    mDragging = false;
 
    if (!IsScrubbing())
@@ -706,7 +709,9 @@ void Scrubber::DoScrub(bool scroll, bool seek)
    }
    else if(!match) {
       mSmoothScrollingScrub = scroll;
-      mProject->GetPlaybackScroller().Activate(scroll);
+      using Mode = AudacityProject::PlaybackScroller::Mode;
+      mProject->GetPlaybackScroller().Activate
+         (scroll ? Mode::Centered : Mode::Off);
       mAlwaysSeeking = seek;
       UncheckAllMenuItems();
       CheckMenuItem();

src/widgets/Ruler.cpp

@@ -2533,7 +2533,8 @@ void AdornedRulerPanel::OnMouseEvents(wxMouseEvent &evt)
 
 void AdornedRulerPanel::HandleQPDoubleClick(wxMouseEvent &evt, wxCoord mousePosX)
 {
-   mProject->GetPlaybackScroller().Activate(true);
+   mProject->GetPlaybackScroller().Activate
+      (AudacityProject::PlaybackScroller::Mode::Centered);
 }
 
 void AdornedRulerPanel::HandleQPClick(wxMouseEvent &evt, wxCoord mousePosX)