Do not store pause state in ControlToolBar...

... Move that into ProjectAudioManager instead, and update the button, only to
reflect it, in idle time.

However, AudioIO also has its mPaused member variable, and it is not obvious
that it was always kept the same as the button state.  No attempt was made
here to identify and fix any bugs, but only to preserve behavior.

src/ProjectAudioManager.h

@@ -35,6 +35,10 @@ public:
    void SetTimerRecordCancelled() { mTimerRecordCanceled = true; }
    void ResetTimerRecordCancelled() { mTimerRecordCanceled = false; }
 
+   bool Paused() const { return mPaused; }
+
+   void SetPaused( bool value ) { mPaused = value; }
+
 private:
    // Audio IO callback methods
    void OnAudioIORate(int rate) override;
@@ -48,6 +52,8 @@ private:
 
    //flag for cancellation of timer record.
    bool mTimerRecordCanceled{ false };
+
+   bool mPaused{ false };
 };
 
 AudioIOStartStreamOptions DefaultPlayOptions( AudacityProject &project );

src/toolbars/ControlToolBar.cpp

@@ -110,8 +110,6 @@ END_EVENT_TABLE()
 ControlToolBar::ControlToolBar( AudacityProject &project )
 : ToolBar(project, TransportBarID, _("Transport"), wxT("Control"))
 {
-   mPaused = false;
-
    gPrefs->Read(wxT("/GUI/ErgonomicTransportButtons"), &mErgonomicTransportButtons, true);
    mStrLocale = gPrefs->Read(wxT("/Locale/Language"), wxT(""));
 
@@ -496,8 +494,8 @@ void ControlToolBar::EnableDisableButtons()
       !(playing && !paused)
    );
    mStop->SetEnabled(CanStopAudioStream() && (playing || recording));
-   mRewind->SetEnabled(IsPauseDown() || (!playing && !recording));
-   mFF->SetEnabled(tracks && (IsPauseDown() || (!playing && !recording)));
+   mRewind->SetEnabled(paused || (!playing && !recording));
+   mFF->SetEnabled(tracks && (paused || (!playing && !recording)));
 
    mPause->SetEnabled(CanStopAudioStream());
 }
@@ -544,11 +542,6 @@ void ControlToolBar::SetRecord(bool down, bool altAppearance)
    EnableDisableButtons();
 }
 
-bool ControlToolBar::IsPauseDown() const
-{
-   return mPause->IsDown();
-}
-
 bool ControlToolBar::IsRecordDown() const
 {
    return mRecord->IsDown();
@@ -842,6 +835,7 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
    StopScrolling();
 
    AudacityProject *project = &mProject;
+   auto &projectAudioManager = ProjectAudioManager::Get( mProject );
 
    if(project) {
       // Let scrubbing code do some appearance change
@@ -866,10 +860,9 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
       gAudioIO->AILADisable();
    #endif
 
-   mPause->PopUp();
-   mPaused=false;
+   projectAudioManager.SetPaused( false );
    //Make sure you tell gAudioIO to unpause
-   gAudioIO->SetPaused(mPaused);
+   gAudioIO->SetPaused( false );
 
    ClearCutPreviewTracks();
 
@@ -1273,21 +1266,14 @@ bool ControlToolBar::DoRecord(AudacityProject &project,
 
 void ControlToolBar::OnPause(wxCommandEvent & WXUNUSED(evt))
 {
+   auto &projectAudioManager = ProjectAudioManager::Get( mProject );
+
    if (!CanStopAudioStream()) {
       return;
    }
 
-
-   if(mPaused)
-   {
-      mPause->PopUp();
-      mPaused=false;
-   }
-   else
-   {
-      mPause->PushDown();
-      mPaused=true;
-   }
+   bool paused = !projectAudioManager.Paused();
+   projectAudioManager.SetPaused( paused );
 
    auto gAudioIO = AudioIO::Get();
 
@@ -1298,7 +1284,7 @@ void ControlToolBar::OnPause(wxCommandEvent & WXUNUSED(evt))
 
    // Bug 1494 - Pausing a seek or scrub should just STOP as
    // it is confusing to be in a paused scrub state.
-   bool bStopInstead = mPaused && 
+   bool bStopInstead = paused &&
       gAudioIO->IsScrubbing() && 
       !scrubber.IsSpeedPlaying();
 
@@ -1309,18 +1295,26 @@ void ControlToolBar::OnPause(wxCommandEvent & WXUNUSED(evt))
    }
    
    if (gAudioIO->IsScrubbing())
-      scrubber.Pause(mPaused);
+      scrubber.Pause(paused);
    else
 #endif
    {
-      gAudioIO->SetPaused(mPaused);
+      gAudioIO->SetPaused(paused);
    }
 }
 
 void ControlToolBar::OnIdle(wxIdleEvent & event)
 {
    event.Skip();
+
+   auto &projectAudioManager = ProjectAudioManager::Get( mProject );
+   if ( projectAudioManager.Paused() )
+      mPause->PushDown();
+   else
+      mPause->PopUp();
+
    UpdateStatusBar();
+   EnableDisableButtons();
 }
 
 void ControlToolBar::OnRewind(wxCommandEvent & WXUNUSED(evt))

src/toolbars/ControlToolBar.h

@@ -97,7 +97,6 @@ class ControlToolBar final : public ToolBar {
    void SetStop(bool down);
    void SetRecord(bool down, bool altAppearance = false);
 
-   bool IsPauseDown() const;
    bool IsRecordDown() const;
 
    // A project is only allowed to stop an audio stream that it owns.
@@ -183,9 +182,6 @@ class ControlToolBar final : public ToolBar {
 
    static AudacityProject *mBusyProject;
 
-   // Maybe button state values shouldn't be duplicated in this toolbar?
-   bool mPaused;         //Play or record is paused or not paused?
-
    // Activate ergonomic order for transport buttons
    bool mErgonomicTransportButtons;
 

src/tracks/ui/Scrubbing.cpp

@@ -869,9 +869,7 @@ void Scrubber::OnActivateOrDeactivateApp(wxActivateEvent &event)
    // Pause if Pause down, or not scrubbing.
    if (!mProject)
       Pause(true);
-   else if ( !ControlToolBar::Find( *mProject ) )
-      Pause( true );
-   else if (ControlToolBar::Get( *mProject ).IsPauseDown())
+   else if (ProjectAudioManager::Get( *mProject ).Paused())
       Pause( true );
    else if (!IsScrubbing())
       Pause( true );