Fix for bug 814

src/AudacityApp.h

@@ -90,6 +90,7 @@ enum
    IsSyncLockedFlag       = 0x08000000,  //awd
    IsRealtimeNotActiveFlag= 0x10000000,  //lll
    CaptureNotBusyFlag     = 0x20000000,
+   CanStopAudioStreamFlag = 0x40000000,
 
    NoFlagsSpecifed        = 0xffffffff
 };

src/AudioIO.h

@@ -219,6 +219,7 @@ class AUDACITY_DLL_API AudioIO final {
    bool IsStreamActive(int token);
 
    wxLongLong GetLastPlaybackTime() const { return mLastPlaybackTimeMillis; }
+   AudacityProject *GetOwningProject() const { return mOwningProject; }
 
 #ifdef EXPERIMENTAL_MIDI_OUT
    /** \brief Compute the current PortMidi timestamp time.

src/Menus.cpp

@@ -796,30 +796,25 @@ void AudacityProject::CreateMenusAndCommands()
       /*i18n-hint: 'Transport' is the name given to the set of controls that
       play, record, pause etc. */
       c->BeginMenu(_("T&ransport"));
-      c->SetDefaultFlags(AudioIONotBusyFlag, AudioIONotBusyFlag);
+      c->SetDefaultFlags(CanStopAudioStreamFlag, CanStopAudioStreamFlag);
 
       /* i18n-hint: (verb) Start or Stop audio playback*/
-      c->AddItem(wxT("PlayStop"), _("Pl&ay/Stop"), FN(OnPlayStop), wxT("Space"),
-         AlwaysEnabledFlag,
-         AlwaysEnabledFlag);
-      c->AddItem(wxT("PlayStopSelect"), _("Play/Stop and &Set Cursor"), FN(OnPlayStopSelect), wxT("Shift+A"),
-         AlwaysEnabledFlag,
-         AlwaysEnabledFlag);
+      c->AddItem(wxT("PlayStop"), _("Pl&ay/Stop"), FN(OnPlayStop), wxT("Space"));
+      c->AddItem(wxT("PlayStopSelect"), _("Play/Stop and &Set Cursor"), FN(OnPlayStopSelect), wxT("Shift+A"));
       c->AddItem(wxT("PlayLooped"), _("&Loop Play"), FN(OnPlayLooped), wxT("Shift+Space"),
-         WaveTracksExistFlag | AudioIONotBusyFlag,
-         WaveTracksExistFlag | AudioIONotBusyFlag);
-      c->AddItem(wxT("Pause"), _("&Pause"), FN(OnPause), wxT("P"),
-         AlwaysEnabledFlag,
-         AlwaysEnabledFlag);
+         WaveTracksExistFlag | AudioIONotBusyFlag | CanStopAudioStreamFlag,
+         WaveTracksExistFlag | AudioIONotBusyFlag | CanStopAudioStreamFlag);
+      c->AddItem(wxT("Pause"), _("&Pause"), FN(OnPause), wxT("P"));
       c->AddItem(wxT("SkipStart"), _("S&kip to Start"), FN(OnSkipStart), wxT("Home"),
-         AudioIONotBusyFlag,
-         AudioIONotBusyFlag);
+                 AudioIONotBusyFlag, AudioIONotBusyFlag);
       c->AddItem(wxT("SkipEnd"), _("Skip to E&nd"), FN(OnSkipEnd), wxT("End"),
-         WaveTracksExistFlag | AudioIONotBusyFlag,
-         WaveTracksExistFlag | AudioIONotBusyFlag);
+                 WaveTracksExistFlag | AudioIONotBusyFlag,
+                 WaveTracksExistFlag | AudioIONotBusyFlag);
 
       c->AddSeparator();
 
+      c->SetDefaultFlags(AudioIONotBusyFlag | CanStopAudioStreamFlag,
+                         AudioIONotBusyFlag | CanStopAudioStreamFlag);
       /* i18n-hint: (verb)*/
       c->AddItem(wxT("Record"), _("&Record"), FN(OnRecord), wxT("R"));
       c->AddItem(wxT("TimerRecord"), _("&Timer Record..."), FN(OnTimerRecord), wxT("Shift+T"));
@@ -1809,6 +1804,10 @@ wxUint32 AudacityProject::GetUpdateFlags()
       if (!mIsCapturing)
       flags |= CaptureNotBusyFlag;
 
+   ControlToolBar *bar = GetControlToolBar();
+   if (bar->ControlToolBar::CanStopAudioStream())
+      flags |= CanStopAudioStreamFlag;
+
    return flags;
 }
 

src/toolbars/ControlToolBar.cpp

@@ -389,12 +389,12 @@ void ControlToolBar::Repaint( wxDC *dc )
 
 void ControlToolBar::EnableDisableButtons()
 {
-   //TIDY-ME: Button logic could be neater.
    AudacityProject *p = GetActiveProject();
    bool tracks = false;
+
    bool playing = mPlay->IsDown();
    bool recording = mRecord->IsDown();
-   bool busy = gAudioIO->IsBusy() || playing || recording;
+   bool notBusy = !gAudioIO->IsBusy();
 
    // Only interested in audio type tracks
    if (p) {
@@ -411,22 +411,18 @@ void ControlToolBar::EnableDisableButtons()
       }
    }
 
-   const bool enablePlay = (!recording) || (tracks && !busy);
-   mPlay->SetEnabled(enablePlay);
-   // Enable and disable the other play button 
-   if (p)
-   {
-      TranscriptionToolBar *const pttb = p->GetTranscriptionToolBar();
-      if (pttb)
-         pttb->SetEnabled(enablePlay);
+   if (p) {
+      TranscriptionToolBar *const playAtSpeedTB = p->GetTranscriptionToolBar();
+      if (playAtSpeedTB)
+         playAtSpeedTB->SetEnabled(CanStopAudioStream() && tracks && !recording);
    }
 
-   mRecord->SetEnabled(!busy && !playing);
-
-   mStop->SetEnabled(busy);
-   mRewind->SetEnabled(!busy);
-   mFF->SetEnabled(tracks && !busy);
-   mPause->SetEnabled(true);
+   mPlay->SetEnabled(CanStopAudioStream() && tracks && !recording);
+   mRecord->SetEnabled(CanStopAudioStream() && notBusy && !playing);
+   mStop->SetEnabled(CanStopAudioStream() && (playing || recording));
+   mRewind->SetEnabled(!playing && !recording);
+   mFF->SetEnabled(tracks && !playing && !recording);
+   mPause->SetEnabled(CanStopAudioStream());
 }
 
 void ControlToolBar::SetPlay(bool down, bool looped, bool cutPreview)
@@ -483,6 +479,9 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
                                    bool backwards, /* = false */
                                    bool playWhiteSpace /* = false */)
 {
+   if (!CanStopAudioStream())
+      return -1;
+
    // Uncomment this for laughs!
    // backwards = true;
 
@@ -667,6 +666,9 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
 void ControlToolBar::PlayCurrentRegion(bool looped /* = false */,
                                        bool cutpreview /* = false */)
 {
+   if (!CanStopAudioStream())
+      return;
+
    AudacityProject *p = GetActiveProject();
 
    if (p)
@@ -695,6 +697,8 @@ void ControlToolBar::OnKeyEvent(wxKeyEvent & event)
       return;
    }
 
+   // 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(GetActiveProject()->GetAudioIOToken())) {
          SetPlay(false);
@@ -713,6 +717,9 @@ void ControlToolBar::OnKeyEvent(wxKeyEvent & event)
 
 void ControlToolBar::OnPlay(wxCommandEvent & WXUNUSED(evt))
 {
+   if (!CanStopAudioStream())
+      return;
+
    StopPlaying();
 
    AudacityProject *p = GetActiveProject();
@@ -724,8 +731,17 @@ void ControlToolBar::OnPlay(wxCommandEvent & WXUNUSED(evt))
 
 void ControlToolBar::OnStop(wxCommandEvent & WXUNUSED(evt))
 {
-   StopPlaying();
-   UpdateStatusBar();
+   if (CanStopAudioStream()) {
+      StopPlaying();
+      UpdateStatusBar();
+   }
+}
+
+bool ControlToolBar::CanStopAudioStream()
+{
+   return (!gAudioIO->IsStreamActive() ||
+           gAudioIO->IsMonitoring() ||
+           gAudioIO->GetOwningProject() == GetActiveProject());
 }
 
 void ControlToolBar::PlayDefault()
@@ -739,6 +755,9 @@ void ControlToolBar::PlayDefault()
 
 void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
 {
+   if (!CanStopAudioStream())
+      return;
+
    mStop->PushDown();
 
    SetStop(false);
@@ -779,8 +798,12 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
 
 void ControlToolBar::Pause()
 {
-   wxCommandEvent dummy;
-   OnPause(dummy);
+   if (!CanStopAudioStream())
+      gAudioIO->SetPaused(!gAudioIO->IsPaused());
+   else {
+      wxCommandEvent dummy;
+      OnPause(dummy);
+   }
 }
 
 void ControlToolBar::OnRecord(wxCommandEvent &evt)
@@ -984,7 +1007,7 @@ void ControlToolBar::OnRecord(wxCommandEvent &evt)
       #ifdef EXPERIMENTAL_AUTOMATED_INPUT_LEVEL_ADJUSTMENT
          gAudioIO->AILAInitialize();
       #endif
-         
+
       AudioIOStartStreamOptions options(p->GetDefaultPlayOptions());
       int token = gAudioIO->StartStream(playbackTracks,
                                         newRecordingTracks,
@@ -1027,6 +1050,10 @@ void ControlToolBar::OnRecord(wxCommandEvent &evt)
 
 void ControlToolBar::OnPause(wxCommandEvent & WXUNUSED(evt))
 {
+   if (!CanStopAudioStream()) {
+      return;
+   }
+
 #ifdef EXPERIMENTAL_SCRUBBING_SUPPORT
    if (gAudioIO->IsScrubbing())
       // Pausing does not make sense.  Force the button

src/toolbars/ControlToolBar.h

@@ -64,6 +64,9 @@ class ControlToolBar final : public ToolBar {
 
    bool IsRecordDown();
 
+   // A project is only allowed to stop an audio stream that it owns.
+   bool CanStopAudioStream ();
+
    // Play currently selected region, or if nothing selected,
    // play from current cursor.
    void PlayCurrentRegion(bool looped = false, bool cutpreview = false);