Update Play button appearance in idle time...

... so most calls to ControlToolBar::SetPlay are removed.  One remains in
TransportMenus, which will not be problematic for untangling dependencies,
and one remains where the toolbar remakes its own buttons.

But the routines that start and stop the streams, importantly, don't use it.

src/ProjectAudioManager.cpp

@@ -192,6 +192,18 @@ void ProjectAudioManager::OnSoundActivationThreshold()
    }
 }
 
+bool ProjectAudioManager::Playing() const
+{
+   auto gAudioIO = AudioIO::Get();
+   return
+      gAudioIO->IsBusy() &&
+      ControlToolBar::Get( mProject ).CanStopAudioStream() &&
+      // ... and not merely monitoring
+      !gAudioIO->IsMonitoring() &&
+      // ... and not punch-and-roll recording
+      gAudioIO->GetNumCaptureChannels() == 0;
+}
+
 bool ProjectAudioManager::Recording() const
 {
    auto gAudioIO = AudioIO::Get();
@@ -265,7 +277,6 @@ bool DoPlayStopSelect
    //If busy, stop playing, make sure everything is unpaused.
    if (scrubber.HasMark() ||
        gAudioIO->IsStreamActive(token)) {
-      toolbar.SetPlay(false);        //Pops
       toolbar.SetStop(true);         //Pushes stop down
 
       // change the selection
@@ -321,7 +332,6 @@ void DoPlayStopSelect(AudacityProject &project)
       toolbar.OnStop(evt);
    else if (!gAudioIO->IsBusy()) {
       //Otherwise, start playing (assuming audio I/O isn't busy)
-      //toolbar->SetPlay(true); // Not needed as set in PlayPlayRegion()
       toolbar.SetStop(false);
 
       // Will automatically set mLastPlayMode

src/ProjectAudioManager.h

@@ -36,16 +36,22 @@ public:
    void ResetTimerRecordCancelled() { mTimerRecordCanceled = false; }
 
    bool Paused() const { return mPaused; }
-   
+
+   bool Playing() const;
+
    // Whether recording into this project (not just into some project) is
    // active
    bool Recording() const;
 
    // Whether the last attempt to start recording requested appending to tracks
    bool Appending() const { return mAppending; }
+   bool Looping() const { return mLooping; }
+   bool Cutting() const { return mCutting; }
 
    void SetPaused( bool value ) { mPaused = value; }
    void SetAppending( bool value ) { mAppending = value; }
+   void SetLooping( bool value ) { mLooping = value; }
+   void SetCutting( bool value ) { mCutting = value; }
 
 private:
    // Audio IO callback methods
@@ -63,6 +69,8 @@ private:
 
    bool mPaused{ false };
    bool mAppending{ false };
+   bool mLooping{ false };
+   bool mCutting{ false };
 };
 
 AudioIOStartStreamOptions DefaultPlayOptions( AudacityProject &project );

src/menus/TransportMenus.cpp

@@ -42,8 +42,7 @@ namespace {
 /// and pops the play button up.  Then, if nothing is now
 /// playing, it pushes the play button down and enables
 /// the stop button.
-bool MakeReadyToPlay(AudacityProject &project,
-   bool loop = false, bool cutpreview = false)
+bool MakeReadyToPlay(AudacityProject &project)
 {
    auto &toolbar = ControlToolBar::Get( project );
    wxCommandEvent evt;
@@ -53,6 +52,7 @@ bool MakeReadyToPlay(AudacityProject &project,
    if (gAudioIO->IsStreamActive(
       ProjectAudioIO::Get( project ).GetAudioIOToken()
    )) {
+      // Make momentary changes of button appearances
       toolbar.SetPlay(false);        //Pops
       toolbar.SetStop(true);         //Pushes stop down
       toolbar.OnStop(evt);
@@ -65,11 +65,6 @@ bool MakeReadyToPlay(AudacityProject &project,
    if (gAudioIO->IsBusy())
       return false;
 
-   ControlToolBar::PlayAppearance appearance =
-      cutpreview ? ControlToolBar::PlayAppearance::CutPreview
-      : loop ? ControlToolBar::PlayAppearance::Looped
-      : ControlToolBar::PlayAppearance::Straight;
-   toolbar.SetPlay(true, appearance);
    toolbar.SetStop(false);
 
    return true;
@@ -97,7 +92,6 @@ void DoPlayStop(const CommandContext &context)
    //If this project is playing, stop playing, make sure everything is unpaused.
    auto gAudioIO = AudioIOBase::Get();
    if (gAudioIO->IsStreamActive(token)) {
-      toolbar.SetPlay(false);        //Pops
       toolbar.SetStop(true);         //Pushes stop down
       toolbar.StopPlaying();
    }
@@ -116,7 +110,6 @@ void DoPlayStop(const CommandContext &context)
       if(iter != finish) {
          auto otherProject = *iter;
          auto &otherToolbar = ControlToolBar::Get( *otherProject );
-         otherToolbar.SetPlay(false);        //Pops
          otherToolbar.SetStop(true);         //Pushes stop down
          otherToolbar.StopPlaying();
       }
@@ -126,7 +119,6 @@ void DoPlayStop(const CommandContext &context)
          //update the playing area
          window.TP_DisplaySelection();
          //Otherwise, start playing (assuming audio I/O isn't busy)
-         //toolbar->SetPlay(true); // Not needed as done in PlayPlayRegion.
          toolbar.SetStop(false);
 
          // Will automatically set mLastPlayMode
@@ -135,7 +127,6 @@ void DoPlayStop(const CommandContext &context)
    }
    else if (!gAudioIO->IsBusy()) {
       //Otherwise, start playing (assuming audio I/O isn't busy)
-      //toolbar->SetPlay(true); // Not needed as done in PlayPlayRegion.
       toolbar.SetStop(false);
 
       // Will automatically set mLastPlayMode
@@ -223,7 +214,7 @@ void OnPlayLooped(const CommandContext &context)
 {
    auto &project = context.project;
 
-   if( !MakeReadyToPlay(project, true) )
+   if( !MakeReadyToPlay(project) )
       return;
 
    // Now play in a loop
@@ -790,7 +781,7 @@ void OnPlayCutPreview(const CommandContext &context)
 {
    auto &project = context.project;
 
-   if ( !MakeReadyToPlay(project, false, true) )
+   if ( !MakeReadyToPlay(project) )
       return;
 
    // Play with cut preview

src/toolbars/ControlToolBar.cpp

@@ -535,6 +535,8 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
                                    bool playWhiteSpace /* = false */)
 // STRONG-GUARANTEE (for state of mCutPreviewTracks)
 {
+   auto &projectAudioManager = ProjectAudioManager::Get( mProject );
+
    if (!CanStopAudioStream())
       return -1;
 
@@ -556,23 +558,12 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
    if (backwards)
       std::swap(t0, t1);
 
-   {
-      PlayAppearance appearance;
-      switch( mode ) {
-         case PlayMode::cutPreviewPlay:
-            appearance = PlayAppearance::CutPreview; break;
-         case PlayMode::loopedPlay:
-            appearance = PlayAppearance::Looped; break;
-         default:
-            appearance = PlayAppearance::Straight; break;
-      }
-      SetPlay(true, appearance);
-   }
+   projectAudioManager.SetLooping( mode == PlayMode::loopedPlay );
+   projectAudioManager.SetCutting( mode == PlayMode::cutPreviewPlay );
 
    bool success = false;
    auto cleanup = finally( [&] {
       if (!success) {
-         SetPlay(false);
          SetStop(false);
       }
    } );
@@ -744,25 +735,28 @@ void ControlToolBar::PlayCurrentRegion(bool looped /* = false */,
 
 void ControlToolBar::OnKeyEvent(wxKeyEvent & event)
 {
+   // PRL: is this handler really ever reached?  Is the ControlToolBar ever
+   // focused?  Isn't there a global event filter that interprets the spacebar
+   // key (or other key chosen in preferences) and dispatches to DoPlayStop,
+   // according to CommandManager's table, before we come to this redundant
+   // function?
+
    if (event.ControlDown() || event.AltDown()) {
       event.Skip();
       return;
    }
 
    auto gAudioIO = AudioIOBase::Get();
+   auto &projectAudioManager = ProjectAudioManager::Get( mProject );
 
    // Does not appear to be needed on Linux. Perhaps on some other platform?
    // If so, "!CanStopAudioStream()" should probably apply.
    if (event.GetKeyCode() == WXK_SPACE) {
-      if (gAudioIO->IsStreamActive(
-         ProjectAudioIO::Get( mProject ).GetAudioIOToken()
-      )) {
-         SetPlay(false);
+      if ( projectAudioManager.Playing() || projectAudioManager.Recording() ) {
          SetStop(true);
          StopPlaying();
       }
       else if (!gAudioIO->IsBusy()) {
-         //SetPlay(true);// Not needed as done in PlayPlayRegion
          SetStop(false);
          PlayCurrentRegion();
       }
@@ -833,7 +827,9 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
    SetStop(false);
    if(stopStream)
       gAudioIO->StopStream();
-   SetPlay(false);
+
+   projectAudioManager.SetLooping( false );
+   projectAudioManager.SetCutting( false );
 
    #ifdef EXPERIMENTAL_AUTOMATED_INPUT_LEVEL_ADJUSTMENT
       gAudioIO->AILADisable();
@@ -1068,7 +1064,6 @@ bool ControlToolBar::DoRecord(AudacityProject &project,
    bool success = false;
    auto cleanup = finally([&] {
       if (!success) {
-         SetPlay(false);
          SetStop(false);
       }
    });
@@ -1296,6 +1291,28 @@ void ControlToolBar::OnIdle(wxIdleEvent & event)
       mRecord->PushDown();
       mRecord->SetAlternateIdx( projectAudioManager.Appending() ? 0 : 1 );
    }
+
+   if ( !(projectAudioManager.Playing() || Scrubber::Get(mProject).HasMark())
+   ) {
+      mPlay->PopUp();
+      mPlay->SetAlternateIdx(
+         wxGetKeyState(WXK_CONTROL)
+         ? 2
+         : wxGetKeyState(WXK_SHIFT)
+            ? 1
+            : 0
+      );
+   }
+   else {
+      mPlay->PushDown();
+      mPlay->SetAlternateIdx(
+         projectAudioManager.Cutting()
+         ? 2
+         : projectAudioManager.Looping()
+            ? 1
+            : 0
+      );
+   }
    
    UpdateStatusBar();
    EnableDisableButtons();

src/tracks/ui/Scrubbing.cpp

@@ -330,7 +330,6 @@ void Scrubber::MarkScrubStart(
    mSeeking = seek;
    CheckMenuItems();
 
-   ctb.SetPlay(true, ControlToolBar::PlayAppearance::Straight );
    // Commented out for Bug 1421
    //   mSeeking
    //   ? ControlToolBar::PlayAppearance::Seek
@@ -732,14 +731,6 @@ void Scrubber::StopScrubbing()
    mDragging = false;
    mSeeking = false;
 
-   if (!IsScrubbing())
-   {
-      // Marked scrub start, but
-      // didn't really play, but did change button apperance
-      auto &ctb = ControlToolBar::Get( *mProject );
-      ctb.SetPlay(false, ControlToolBar::PlayAppearance::Straight);
-   }
-
    AdornedRulerPanel::Get( *mProject ).DrawBothOverlays();
    CheckMenuItems();
 }