New preference for pinned play head, also in Transport menu

src/Menus.cpp

@@ -69,6 +69,7 @@ simplifies construction of menu items.
 #include "export/Export.h"
 #include "export/ExportMultiple.h"
 #include "prefs/PrefsDialog.h"
+#include "prefs/PlaybackPrefs.h"
 #include "ShuttleGui.h"
 #include "HistoryWindow.h"
 #include "LyricsWindow.h"
@@ -772,6 +773,11 @@ void AudacityProject::CreateMenusAndCommands()
 
       c->AddSeparator();
 
+      c->AddCheck(wxT("PinnedHead"), _("Pinned Recording/Playback Head"),
+                  FN(OnTogglePinnedHead), 0,
+                  // Switching of scrolling on and off is permitted even during transport
+                  AlwaysEnabledFlag, AlwaysEnabledFlag);
+
       c->AddCheck(wxT("Duplex"), _("&Overdub (on/off)"), FN(OnTogglePlayRecording), 0);
       c->AddCheck(wxT("SWPlaythrough"), _("So&ftware Playthrough (on/off)"), FN(OnToggleSWPlaythrough), 0);
 
@@ -1840,6 +1846,10 @@ void AudacityProject::ModifyToolbarMenus()
    gPrefs->Read(wxT("/AudioIO/AutomatedInputLevelAdjustment"),&active, false);
    mCommandManager.Check(wxT("AutomatedInputLevelAdjustmentOnOff"), active);
 #endif
+
+   active = PlaybackPrefs::GetPinnedHeadPreference();
+   mCommandManager.Check(wxT("PinnedHead"), active);
+
    gPrefs->Read(wxT("/AudioIO/Duplex"),&active, true);
    mCommandManager.Check(wxT("Duplex"), active);
    gPrefs->Read(wxT("/AudioIO/SWPlaythrough"),&active, false);
@@ -2360,6 +2370,18 @@ void AudacityProject::OnToggleSoundActivated()
    ModifyAllProjectToolbarMenus();
 }
 
+void AudacityProject::OnTogglePinnedHead()
+{
+   PlaybackPrefs::SetPinnedHeadPreference(
+      !PlaybackPrefs::GetPinnedHeadPreference(), true);
+   ModifyAllProjectToolbarMenus();
+
+   // Change what happens in case transport is in progress right now
+   auto ctb = GetActiveProject()->GetControlToolBar();
+   if (ctb)
+      ctb->StartScrollingIfPreferred();
+}
+
 void AudacityProject::OnTogglePlayRecording()
 {
    bool Duplex;

src/Menus.h

@@ -313,6 +313,7 @@ void OnResetToolBars();
 
 void OnSoundActivated();
 void OnToggleSoundActivated();
+void OnTogglePinnedHead();
 void OnTogglePlayRecording();
 void OnToggleSWPlaythrough();
 #ifdef EXPERIMENTAL_AUTOMATED_INPUT_LEVEL_ADJUSTMENT

src/prefs/PlaybackPrefs.cpp

@@ -19,13 +19,25 @@
 *//********************************************************************/
 
 #include "../Audacity.h"
+#include "PlaybackPrefs.h"
 
 #include <wx/defs.h>
 #include <wx/textctrl.h>
 
 #include "../ShuttleGui.h"
+#include "../Prefs.h"
 
-#include "PlaybackPrefs.h"
+namespace {
+   const wxChar *PinnedHeadPreferenceKey()
+   {
+      return wxT("/AudioIO/PinnedHead");
+   }
+
+   bool PinnedHeadPreferenceDefault()
+   {
+      return false;
+   }
+}
 
 PlaybackPrefs::PlaybackPrefs(wxWindow * parent)
 :  PrefsPanel(parent, _("Playback"))
@@ -113,6 +125,11 @@ void PlaybackPrefs::PopulateOrExchange(ShuttleGui & S)
       S.EndThreeColumn();
    }
    S.EndStatic();
+
+   // This affects recording too, though it is in playback preferences.
+   S.TieCheckBox(_("Pinned playback/recording head"),
+                 PinnedHeadPreferenceKey(),
+                 PinnedHeadPreferenceDefault());
 }
 
 bool PlaybackPrefs::Apply()
@@ -123,8 +140,21 @@ bool PlaybackPrefs::Apply()
    return true;
 }
 
+bool PlaybackPrefs::GetPinnedHeadPreference()
+{
+   return gPrefs->ReadBool(PinnedHeadPreferenceKey(), PinnedHeadPreferenceDefault());
+}
+
+void PlaybackPrefs::SetPinnedHeadPreference(bool value, bool flush)
+{
+   gPrefs->Write(PinnedHeadPreferenceKey(), value);
+   if(flush)
+      gPrefs->Flush();
+}
+
 PrefsPanel *PlaybackPrefsFactory::Create(wxWindow *parent)
 {
    wxASSERT(parent); // to justify safenew
    return safenew PlaybackPrefs(parent);
 }
+

src/prefs/PlaybackPrefs.h

@@ -27,6 +27,9 @@ class PlaybackPrefs final : public PrefsPanel
    virtual ~PlaybackPrefs();
    bool Apply() override;
 
+   static bool GetPinnedHeadPreference();
+   static void SetPinnedHeadPreference(bool value, bool flush = false);
+
  private:
    void Populate();
    void PopulateOrExchange(ShuttleGui & S);

src/toolbars/ControlToolBar.cpp

@@ -68,6 +68,7 @@
 #include "../widgets/Meter.h"
 
 #include "../tracks/ui/Scrubbing.h"
+#include "../prefs/PlaybackPrefs.h"
 
 IMPLEMENT_CLASS(ControlToolBar, ToolBar);
 
@@ -635,15 +636,16 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
                NoteTrackArray(),
 #endif
                tcp0, tcp1, myOptions);
-         } else
+         }
-         {
+         else {
             // Cannot create cut preview tracks, clean up and exit
             SetPlay(false);
             SetStop(false);
             SetRecord(false);
             return -1;
          }
-      } else {
+      }
+      else {
          // Lifted the following into AudacityProject::GetDefaultPlayOptions()
          /*
          if (!timetrack) {
@@ -682,6 +684,8 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
       return -1;
    }
 
+   StartScrollingIfPreferred();
+
    // Let other UI update appearance
    if (p)
       p->GetRulerPanel()->HideQuickPlayIndicator();
@@ -1076,6 +1080,8 @@ void ControlToolBar::OnRecord(wxCommandEvent &evt)
       if (success) {
          p->SetAudioIOToken(token);
          mBusyProject = p;
+
+         StartScrollingIfPreferred();
       }
       else {
          if (shifted) {
@@ -1263,6 +1269,14 @@ void ControlToolBar::UpdateStatusBar(AudacityProject *pProject)
    pProject->GetStatusBar()->SetStatusText(StateForStatusBar(), stateStatusBarField);
 }
 
+void ControlToolBar::StartScrollingIfPreferred()
+{
+   if (PlaybackPrefs::GetPinnedHeadPreference())
+      StartScrolling();
+   else
+      StopScrolling();
+}
+
 void ControlToolBar::StartScrolling()
 {
    using Mode = AudacityProject::PlaybackScroller::Mode;

src/toolbars/ControlToolBar.h

@@ -107,6 +107,7 @@ class ControlToolBar final : public ToolBar {
    void UpdateStatusBar(AudacityProject *pProject);
 
    // Starting and stopping of scrolling display
+   void StartScrollingIfPreferred();
    void StartScrolling();
    void StopScrolling();