Break dependency cycles related to Commands

src/Screenshot.cpp

@@ -95,7 +95,7 @@ class ScreenFrame final : public wxFrame
    wxStatusBar *mStatus;
 
    std::unique_ptr<ScreenshotCommand> mCommand;
-   CommandContext mContext;
+   const CommandContext mContext;
 
    DECLARE_EVENT_TABLE()
 };
@@ -469,7 +469,7 @@ void ScreenFrame::PopulateOrExchange(ShuttleGui & S)
       CentreOnParent();
    }
 
-   SetIcon(mContext.GetProject()->GetIcon());
+   SetIcon(mContext.project.GetIcon());
 }
 
 bool ScreenFrame::ProcessEvent(wxEvent & e)
@@ -564,8 +564,8 @@ void ScreenFrame::SizeMainWindow(int w, int h)
 {
    int top = 20;
 
-   mContext.GetProject()->Maximize(false);
+   mContext.project.Maximize(false);
-   mContext.GetProject()->SetSize(16, 16 + top, w, h);
+   mContext.project.SetSize(16, 16 + top, w, h);
    //Bug383 - Toolbar Resets not wanted.
    //mContext.GetProject()->GetToolManager()->Reset();
 }
@@ -669,9 +669,9 @@ void ScreenFrame::OnCaptureSomething(wxCommandEvent &  event)
 void ScreenFrame::TimeZoom(double seconds)
 {
    int width, height;
-   mContext.GetProject()->GetClientSize(&width, &height);
+   mContext.project.GetClientSize(&width, &height);
-   mContext.GetProject()->mViewInfo.SetZoom((0.75 * width) / seconds);
+   mContext.project.mViewInfo.SetZoom((0.75 * width) / seconds);
-   mContext.GetProject()->RedrawProject();
+   mContext.project.RedrawProject();
 }
 
 void ScreenFrame::OnOneSec(wxCommandEvent & WXUNUSED(event))
@@ -708,7 +708,7 @@ void ScreenFrame::SizeTracks(int h)
    // If there should be more-than-stereo tracks, this makes
    // each channel as high as for a stereo channel
 
-   auto tracks = mContext.GetProject()->GetTracks();
+   auto tracks = mContext.project.GetTracks();
    for (auto t : tracks->Leaders<WaveTrack>()) {
       auto channels = TrackList::Channels(t);
       auto nChannels = channels.size();
@@ -716,15 +716,15 @@ void ScreenFrame::SizeTracks(int h)
       for (auto channel : channels)
          channel->SetHeight(height);
    }
-   mContext.GetProject()->RedrawProject();
+   mContext.project.RedrawProject();
 }
 
 void ScreenFrame::OnShortTracks(wxCommandEvent & WXUNUSED(event))
 {
-   for (auto t : mContext.GetProject()->GetTracks()->Any<WaveTrack>())
+   for (auto t : mContext.project.GetTracks()->Any<WaveTrack>())
       t->SetHeight(t->GetMinimizedHeight());
 
-   mContext.GetProject()->RedrawProject();
+   mContext.project.RedrawProject();
 }
 
 void ScreenFrame::OnMedTracks(wxCommandEvent & WXUNUSED(event))

src/commands/AudacityCommand.cpp

@@ -37,17 +37,33 @@ ShuttleGui.
 
 #include "audacity/ConfigInterface.h"
 
-#include "../Project.h"
 #include "../Shuttle.h"
 #include "../ShuttleGui.h"
 #include "../widgets/ProgressDialog.h"
 #include "../widgets/HelpSystem.h"
 #include "../widgets/ErrorDialog.h"
 
-#include "../commands/ScreenshotCommand.h"
-
 #include <unordered_map>
 
+namespace {
+
+AudacityCommand::VetoDialogHook &GetVetoDialogHook()
+{
+   static AudacityCommand::VetoDialogHook sHook = nullptr;
+   return sHook;
+}
+
+}
+
+auto AudacityCommand::SetVetoDialogHook( VetoDialogHook hook )
+   -> VetoDialogHook
+{
+   auto &theHook = GetVetoDialogHook();
+   auto result = theHook;
+   theHook = hook;
+   return result;
+}
+
 AudacityCommand::AudacityCommand()
 {
    mProgress = NULL;
@@ -70,12 +86,6 @@ VendorSymbol AudacityCommand::GetVendor(){      return XO("Audacity");}
 wxString AudacityCommand::GetVersion(){     return AUDACITY_VERSION_STRING;}
 
 
-bool AudacityCommand::Apply() { 
-   AudacityProject * pProj = GetActiveProject();
-   const CommandContext context( *pProj );
-   return Apply( context );
-};
-
 bool AudacityCommand::Init(){
    if( !mNeedsInit )
       return true;
@@ -105,7 +115,8 @@ bool AudacityCommand::ShowInterface(wxWindow *parent, bool WXUNUSED(forceModal))
    mUIDialog->SetMinSize(mUIDialog->GetSize());
 
    // The Screenshot command might be popping this dialog up, just to capture it.
-   if( ScreenshotCommand::MayCapture( mUIDialog ) )
+   auto hook = GetVetoDialogHook();
+   if( hook && hook( mUIDialog ) )
       return false;
 
    bool res = mUIDialog->ShowModal() != 0;

src/commands/AudacityCommand.h

@@ -45,6 +45,11 @@ class AUDACITY_DLL_API AudacityCommand /* not final */ : public wxEvtHandler,
  public:
    AudacityCommand();
    virtual ~AudacityCommand();
+   
+   // Type of a registered function that, if it returns true,
+   // causes ShowInterface to return early without making any dialog
+   using VetoDialogHook = bool (*) ( wxDialog* );
+   static VetoDialogHook SetVetoDialogHook( VetoDialogHook hook );
 
    // ComponentInterface implementation
 
@@ -64,8 +69,7 @@ class AUDACITY_DLL_API AudacityCommand /* not final */ : public wxEvtHandler,
    virtual bool IsBatchProcessing(){ return mIsBatch;}
    virtual void SetBatchProcessing(bool start){ mIsBatch = start;};
    
-   virtual bool Apply(const CommandContext & WXUNUSED(context) ) {return false;}; 
+   virtual bool Apply(const CommandContext & WXUNUSED(context) ) {return false;};
-   virtual bool Apply(); // redirects to the command context version.
 
    bool ShowInterface(wxWindow *parent, bool forceModal = false);
    virtual void SetHostUI(EffectUIHostInterface * WXUNUSED(host)){;};

src/commands/BatchEvalCommand.cpp

@@ -17,6 +17,12 @@
 #include "BatchEvalCommand.h"
 
 #include "CommandContext.h"
+#include "CommandDirectory.h"
+#include "../Project.h"
+
+static CommandDirectory::RegisterType sRegisterType{
+   std::make_unique<BatchEvalCommandType>()
+};
 
 ComponentInterfaceSymbol BatchEvalCommandType::BuildName()
 {
@@ -35,7 +41,7 @@ void BatchEvalCommandType::BuildSignature(CommandSignature &signature)
 
 OldStyleCommandPointer BatchEvalCommandType::Create(std::unique_ptr<CommandOutputTargets> && WXUNUSED(target))
 {
-   return std::make_shared<BatchEvalCommand>(*this);
+   return std::make_shared<BatchEvalCommand>(*GetActiveProject(), *this);
 }
 
 bool BatchEvalCommand::Apply(const CommandContext & context)

src/commands/BatchEvalCommand.h

@@ -26,6 +26,8 @@ to that system.
 #include "CommandType.h"
 #include "../BatchCommands.h"
 
+class AudacityProject;
+
 class BatchEvalCommandType final : public OldStyleCommandType
 {
 public:
@@ -37,8 +39,8 @@ public:
 class BatchEvalCommand final : public CommandImplementation
 {
 public:
-   BatchEvalCommand(OldStyleCommandType &type)
+   BatchEvalCommand(AudacityProject &project, OldStyleCommandType &type)
-      : CommandImplementation(type)
+      : CommandImplementation(project, type)
    { }
 
    virtual ~BatchEvalCommand();

src/commands/Command.cpp

@@ -79,16 +79,17 @@ classes derived from it.
 #include "Command.h"
 
 #include <map>
+#include <wx/log.h>
 #include <wx/string.h>
 #include <wx/variant.h>
 #include <wx/arrstr.h>
 
-#include "CommandBuilder.h"
 #include "CommandTargets.h"
 #include "CommandDirectory.h"
 
 #include "CommandContext.h"
-#include "../Project.h"
+
+#include "../AudacityException.h"
 
 
 
@@ -119,9 +120,10 @@ bool DecoratedCommand::SetParameter(const wxString &paramName,
    return mCommand->SetParameter(paramName, paramValue);
 }
 
-ApplyAndSendResponse::ApplyAndSendResponse(const OldStyleCommandPointer &cmd, std::unique_ptr<CommandOutputTargets> &target)
+ApplyAndSendResponse::ApplyAndSendResponse(
+   const OldStyleCommandPointer &cmd, std::unique_ptr<CommandOutputTargets> &target)
       : DecoratedCommand(cmd),
-       mCtx( std::make_unique<CommandContext>( *GetActiveProject(), std::move(target) ) )
+       mCtx( std::make_unique<CommandContext>( cmd->mProject, std::move(target) ) )
 {
 }
 
@@ -167,8 +169,10 @@ bool ApplyAndSendResponse::Apply()
    return result;
 }
 
-CommandImplementation::CommandImplementation(OldStyleCommandType &type)
+CommandImplementation::CommandImplementation(
-: mType(type),
+  AudacityProject &project, OldStyleCommandType &type)
+:  OldStyleCommand{ project },
+   mType(type),
    mParams(type.GetSignature().GetDefaults()),
    mSetParams()
 {
@@ -257,7 +261,7 @@ CommandSignature &CommandImplementation::GetSignature()
 bool CommandImplementation::SetParameter(const wxString &paramName, const wxVariant &paramValue)
 {
    wxASSERT(!paramValue.IsType(wxT("null")));
-   CommandContext context( * GetActiveProject());
+   CommandContext context( mProject );
    ParamValueMap::iterator iter = mParams.find(paramName);
    if (iter == mParams.end())
    {

src/commands/Command.h

@@ -28,7 +28,9 @@ class CommandOutputTargets;
 class OldStyleCommand /* not final */
 {
 public:
-   OldStyleCommand() {};
+   AudacityProject &mProject;
+
+   OldStyleCommand(AudacityProject &project) : mProject{ project } {};
    virtual ~OldStyleCommand() { }
    virtual ComponentInterfaceSymbol GetSymbol() = 0;
    virtual CommandSignature &GetSignature() = 0;
@@ -47,7 +49,7 @@ protected:
    OldStyleCommandPointer mCommand;
 public:
    DecoratedCommand(const OldStyleCommandPointer &cmd)
-      : mCommand(cmd)
+      : OldStyleCommand{ cmd->mProject }, mCommand(cmd)
    {
       wxASSERT(cmd != NULL);
    }
@@ -62,10 +64,11 @@ public:
 class ApplyAndSendResponse : public DecoratedCommand
 {
 public:
-   ApplyAndSendResponse(const OldStyleCommandPointer &cmd, std::unique_ptr<CommandOutputTargets> &target);
+   ApplyAndSendResponse(
+      const OldStyleCommandPointer &cmd, std::unique_ptr<CommandOutputTargets> &target);
    bool Apply() override;
    bool Apply(const CommandContext &context) override;// Error to use this.
-   std::unique_ptr<CommandContext> mCtx;
+   std::unique_ptr<const CommandContext> mCtx;
 
 };
 
@@ -95,7 +98,7 @@ protected:
 public:
    /// Constructor should not be called directly; only by a factory which
    /// ensures name and params are set appropriately for the command.
-   CommandImplementation(OldStyleCommandType &type);
+   CommandImplementation(AudacityProject &project, OldStyleCommandType &type);
 
    virtual ~CommandImplementation();
 

src/commands/CommandBuilder.cpp

@@ -25,7 +25,7 @@ system by constructing BatchCommandEval objects.
 #include "CommandBuilder.h"
 
 #include "CommandDirectory.h"
-#include "BatchEvalCommand.h"
+#include "Command.h"
 #include "ScriptCommandRelay.h"
 #include "CommandContext.h"
 #include "CommandTargets.h"

src/commands/CommandContext.cpp

@@ -24,15 +24,13 @@ messaging from a command back to its invoker.
 #include "CommandContext.h"
 
 #include <map>
+#include <wx/app.h>
+#include <wx/log.h>
 #include <wx/string.h>
 #include <wx/variant.h>
 #include <wx/arrstr.h>
 
-#include "CommandBuilder.h"
 #include "CommandTargets.h"
-#include "CommandDirectory.h"
-
-#include "../Project.h"
 
 CommandContext::CommandContext(
       AudacityProject &p
@@ -92,9 +90,6 @@ void CommandContext::Progress( double d ) const
 AudacityApp * CommandContext::GetApp() const
 {  return (AudacityApp *) wxTheApp;}
 
-AudacityProject *CommandContext::GetProject() const
-{  return GetActiveProject();}
-
 void CommandContext::StartArray() const
 {
    if( pOutput )

src/commands/CommandContext.h

@@ -11,8 +11,8 @@
 #ifndef __AUDACITY_COMMAND_CONTEXT__
 #define __AUDACITY_COMMAND_CONTEXT__
 
+#include <memory>
 #include "audacity/Types.h"
-#include "Command.h"
 
 class AudacityProject;
 class AudacityApp;
@@ -56,6 +56,5 @@ public:
    int index;
    CommandParameter parameter;
    AudacityApp *GetApp() const;
-   AudacityProject *GetProject() const;
 };
 #endif

src/commands/CommandDirectory.cpp

@@ -17,10 +17,6 @@ functions to look up a command by name.
 #include "../Audacity.h"
 #include "CommandDirectory.h"
 
-#include "HelpCommand.h"
-#include "MessageCommand.h"
-#include "BatchEvalCommand.h"
-
 std::unique_ptr<CommandDirectory> CommandDirectory::mInstance;
 
 CommandDirectory::CommandDirectory()
@@ -28,7 +24,8 @@ CommandDirectory::CommandDirectory()
    // Create the command map.
    // First we have commands which return information
    //AddCommand(std::make_unique<MessageCommandType>());
-   AddCommand(std::make_unique<BatchEvalCommandType>());
+
+//   AddCommand(std::make_unique<BatchEvalCommandType>());
 
 
    // Legacy adapter commands that previously was needed to 
@@ -68,24 +65,30 @@ CommandDirectory::~CommandDirectory()
 
 OldStyleCommandType *CommandDirectory::LookUp(const wxString &cmdName) const
 {
-   CommandMap::const_iterator iter = mCmdMap.find(cmdName);
+   auto iter = sCmdMap().find(cmdName);
-   if (iter == mCmdMap.end())
+   if (iter == sCmdMap().end())
    {
-      return NULL;
+      return nullptr;
    }
    return iter->second.get();
 }
 
-void CommandDirectory::AddCommand(std::unique_ptr<OldStyleCommandType> &&type)
+CommandMap &CommandDirectory::sCmdMap()
+{
+   static CommandMap theMap;
+   return theMap;
+}
+
+void CommandDirectory::AddCommand(std::unique_ptr<OldStyleCommandType> type)
 {
    wxASSERT(type != NULL);
    // Internal string is shown but only in assertion message
    auto cmdName = type->GetSymbol().Internal();
-   wxASSERT_MSG(mCmdMap.find(cmdName) == mCmdMap.end()
+   wxASSERT_MSG(sCmdMap().find(cmdName) == sCmdMap().end()
          , wxT("A command named ") + cmdName
          + wxT(" already exists."));
 
-   mCmdMap[cmdName] = std::move(type);
+   sCmdMap()[cmdName] = std::move(type);
 }
 
 CommandDirectory *CommandDirectory::Get()

src/commands/CommandDirectory.h

@@ -31,8 +31,17 @@ class CommandDirectory
 {
 private:
    static std::unique_ptr<CommandDirectory> mInstance;
-   CommandMap mCmdMap;
+   static CommandMap &sCmdMap();
+
+   static void AddCommand(std::unique_ptr<OldStyleCommandType> type);
 public:
+   /// Register a type of command with the directory with a statically
+   /// constructed instance of this class.
+   struct RegisterType{
+     RegisterType( std::unique_ptr<OldStyleCommandType> type )
+        { AddCommand( std::move( type ) ); }
+   };
+
    ~CommandDirectory();
 
    /// If a command with the given name has been registered in the directory,
@@ -40,9 +49,6 @@ public:
    /// Otherwise return NULL.
    OldStyleCommandType *LookUp(const wxString &cmdName) const;
 
-   /// Register a type of command with the directory.
-   void AddCommand(std::unique_ptr<OldStyleCommandType> &&type);
-
    /// Get a pointer to the singleton instance
    static CommandDirectory *Get();
 

src/commands/CommandHandler.cpp

@@ -24,6 +24,7 @@
 #include "AppCommandEvent.h"
 #include "ScriptCommandRelay.h"
 #include "../commands/CommandContext.h"
+#include "../commands/Command.h"
 
 CommandHandler::CommandHandler()
  : mCurrentContext(std::make_unique<CommandContext>
@@ -59,5 +60,5 @@ void CommandHandler::OnReceiveCommand(AppCommandEvent &event)
    wxUnusedVar(result);
 
    // Redraw the project
-   mCurrentContext->GetProject()->RedrawProject();
+   mCurrentContext->project.RedrawProject();
 }

src/commands/CommandHandler.h

@@ -25,7 +25,7 @@ class CommandContext;
 class CommandHandler
 {
    private:
-      std::unique_ptr<CommandContext> mCurrentContext;
+      std::unique_ptr<const CommandContext> mCurrentContext;
 
    public:
       CommandHandler();

src/commands/CommandTargets.cpp

@@ -24,9 +24,10 @@ capture the more lengthy output from some commands.
 #include "../Audacity.h"
 #include "CommandTargets.h"
 
+#include <wx/app.h>
+#include <wx/statusbr.h>
 #include <wx/string.h>
 #include "../ShuttleGui.h"
-#include "../Project.h"
 #include "../widgets/ErrorDialog.h"
 
 void CommandMessageTarget::StartArray()
@@ -375,7 +376,8 @@ void LongMessageDialog::OnCancel(wxCommandEvent & WXUNUSED(evt)){
 void LongMessageDialog::AcceptText( const wxString & Text )
 {
    if( pDlg == NULL ){
-      pDlg = new LongMessageDialog( GetActiveProject(), _( "Long Message" ) );
+      pDlg = new LongMessageDialog(
+         wxTheApp->GetTopWindow(), _( "Long Message" ) );
       pDlg->Init();
       pDlg->Show();
    }

src/commands/CompareAudioCommand.cpp

@@ -46,10 +46,6 @@ bool CompareAudioCommand::DefineParams( ShuttleParams & S ){
    return true;
 }
 
-bool CompareAudioCommand::Apply(){
-   return true;
-}
-
 void CompareAudioCommand::PopulateOrExchange(ShuttleGui & S)
 {
    S.AddSpace(0, 5);
@@ -107,7 +103,7 @@ inline int min(int a, int b)
 
 bool CompareAudioCommand::Apply(const CommandContext & context)
 {
-   if (!GetSelection(context, *context.GetProject()))
+   if (!GetSelection(context, context.project))
    {
       return false;
    }

src/commands/CompareAudioCommand.h

@@ -33,7 +33,6 @@ public:
    wxString GetDescription() override {return _("Compares a range on two tracks.");};
    bool DefineParams( ShuttleParams & S ) override;
    void PopulateOrExchange(ShuttleGui & S) override;
-   bool Apply() override;
 
    // AudacityCommand overrides
    wxString ManualPage() override {return wxT("Extra_Menu:_Scriptables_II#compare_Audio");};

src/commands/DragCommand.cpp

@@ -90,7 +90,7 @@ bool DragCommand::Apply(const CommandContext & context)
    if( !bHasToY )
       mToY = 10;
 
-   wxWindow * pWin = context.GetProject();
+   wxWindow * pWin = &context.project;
    wxWindow * pWin1 = nullptr;
    wxMouseEvent Evt( wxEVT_MOTION );
    Evt.m_x = mFromX;

src/commands/GetInfoCommand.cpp

@@ -121,7 +121,7 @@ bool GetInfoCommand::Apply(const CommandContext &context)
    if( mFormat == kLisp )
    {
       CommandContext LispyContext( 
-         *(context.GetProject()), 
+         context.project,
          std::make_unique<LispifiedCommandOutputTargets>( *context.pOutput.get() )
          );
       return ApplyInner( LispyContext );
@@ -130,7 +130,7 @@ bool GetInfoCommand::Apply(const CommandContext &context)
    if( mFormat == kBrief )
    {
       CommandContext BriefContext( 
-         *(context.GetProject()), 
+         context.project,
          std::make_unique<BriefCommandOutputTargets>( *context.pOutput.get() )
          );
       return ApplyInner( BriefContext );
@@ -159,7 +159,7 @@ bool GetInfoCommand::ApplyInner(const CommandContext &context)
 
 bool GetInfoCommand::SendMenus(const CommandContext &context)
 {
-   wxMenuBar * pBar = context.GetProject()->GetMenuBar();
+   wxMenuBar * pBar = context.project.GetMenuBar();
    if(!pBar ){
       wxLogDebug("No menus");
       return false;
@@ -418,10 +418,10 @@ wxSpinCtrl * ShuttleGuiGetDefinition::TieSpinCtrl(
 bool GetInfoCommand::SendPreferences(const CommandContext &context)
 {
    context.StartArray();
-   GlobalPrefsDialog dialog( context.GetProject() );
+   GlobalPrefsDialog dialog( &context.project );
    // wxCommandEvent Evt;
    //dialog.Show();
-   wxWindow * pWin = context.GetProject();
+   wxWindow * pWin = &context.project;
    ShuttleGuiGetDefinition S(pWin, *((context.pOutput)->mStatusTarget) );
    dialog.ShuttleAll( S );
    context.EndArray();
@@ -454,7 +454,7 @@ bool GetInfoCommand::SendCommands(const CommandContext &context, int flags )
 bool GetInfoCommand::SendBoxes(const CommandContext &context)
 {
    //context.Status("Boxes");
-   wxWindow * pWin = context.GetProject();
+   wxWindow * pWin = &context.project;
 
    context.StartArray();
    wxRect R = pWin->GetScreenRect();
@@ -483,11 +483,11 @@ bool GetInfoCommand::SendBoxes(const CommandContext &context)
 
 bool GetInfoCommand::SendTracks(const CommandContext & context)
 {
-   TrackList *projTracks = context.GetProject()->GetTracks();
+   TrackList *projTracks = context.project.GetTracks();
    context.StartArray();
    for (auto trk : projTracks->Leaders())
    {
-      TrackPanel *panel = context.GetProject()->GetTrackPanel();
+      TrackPanel *panel = context.project.GetTrackPanel();
       Track * fTrack = panel->GetFocusedTrack();
 
       context.StartStruct();
@@ -530,7 +530,7 @@ bool GetInfoCommand::SendTracks(const CommandContext & context)
 
 bool GetInfoCommand::SendClips(const CommandContext &context)
 {
-   TrackList *tracks = context.GetProject()->GetTracks();
+   TrackList *tracks = context.project.GetTracks();
    int i=0;
    context.StartArray();
    for (auto waveTrack : tracks->Leaders<WaveTrack>()) {
@@ -552,7 +552,7 @@ bool GetInfoCommand::SendClips(const CommandContext &context)
 
 bool GetInfoCommand::SendEnvelopes(const CommandContext &context)
 {
-   TrackList *tracks = context.GetProject()->GetTracks();
+   TrackList *tracks = context.project.GetTracks();
    int i=0;
    int j=0;
    context.StartArray();
@@ -589,7 +589,7 @@ bool GetInfoCommand::SendEnvelopes(const CommandContext &context)
 
 bool GetInfoCommand::SendLabels(const CommandContext &context)
 {
-   TrackList *tracks = context.GetProject()->GetTracks();
+   TrackList *tracks = context.project.GetTracks();
    int i=0;
    context.StartArray();
    for (auto t : tracks->Leaders()) {
@@ -640,7 +640,7 @@ void GetInfoCommand::ExploreMenu( const CommandContext &context, wxMenu * pMenu,
    if( !pMenu )
       return;
 
-   CommandManager * pMan = context.GetProject()->GetCommandManager();
+   CommandManager * pMan = context.project.GetCommandManager();
 
    wxMenuItemList list = pMenu->GetMenuItems();
    size_t lcnt = list.size();
@@ -714,7 +714,7 @@ void GetInfoCommand::ExploreAdornments( const CommandContext &context,
 void GetInfoCommand::ExploreTrackPanel( const CommandContext &context,
    wxPoint P, wxWindow * pWin, int WXUNUSED(Id), int depth )
 {
-   AudacityProject * pProj = context.GetProject();
+   AudacityProject * pProj = &context.project;
    TrackPanel * pTP = pProj->GetTrackPanel();
 
    wxRect trackRect = pWin->GetRect();

src/commands/ImportExportCommands.cpp

@@ -40,7 +40,7 @@ void ImportCommand::PopulateOrExchange(ShuttleGui & S)
 }
 
 bool ImportCommand::Apply(const CommandContext & context){
-   return context.GetProject()->Import(mFileName);
+   return context.project.Import(mFileName);
 }
 
 
@@ -66,8 +66,8 @@ void ExportCommand::PopulateOrExchange(ShuttleGui & S)
 bool ExportCommand::Apply(const CommandContext & context)
 {
    double t0, t1;
-   t0 = context.GetProject()->mViewInfo.selectedRegion.t0();
+   t0 = context.project.mViewInfo.selectedRegion.t0();
-   t1 = context.GetProject()->mViewInfo.selectedRegion.t1();
+   t1 = context.project.mViewInfo.selectedRegion.t1();
 
    // Find the extension and check it's valid
    int splitAt = mFileName.Find(wxUniChar('.'), true);
@@ -80,7 +80,7 @@ bool ExportCommand::Apply(const CommandContext & context)
 
    Exporter exporter;
 
-   bool exportSuccess = exporter.Process(context.GetProject(),
+   bool exportSuccess = exporter.Process(&context.project,
                                          std::max(0, mnChannels),
                                          extension, mFileName,
                                          true, t0, t1);

src/commands/OpenSaveCommands.cpp

@@ -44,17 +44,17 @@ void OpenProjectCommand::PopulateOrExchange(ShuttleGui & S)
 
 bool OpenProjectCommand::Apply(const CommandContext & context){
 
-   auto oldFileName = context.GetProject()->GetFileName();
+   auto oldFileName = context.project.GetFileName();
    if(mFileName.empty())
    {
-      auto project = context.GetProject();
+      auto project = &context.project;
       AudacityProject::OpenFiles(project);
    }
    else
    {
-      context.GetProject()->OpenFile(mFileName, mbAddToHistory);
+      context.project.OpenFile(mFileName, mbAddToHistory);
    }
-   const auto &newFileName = context.GetProject()->GetFileName();
+   const auto &newFileName = context.project.GetFileName();
 
    // Because Open does not return a success or failure, we have to guess
    // at this point, based on whether the project file name has
@@ -85,7 +85,7 @@ void SaveProjectCommand::PopulateOrExchange(ShuttleGui & S)
 bool SaveProjectCommand::Apply(const CommandContext &context)
 {
    if(mFileName.empty())
-      return context.GetProject()->SaveAs(mbCompress);
+      return context.project.SaveAs(mbCompress);
    else
-      return context.GetProject()->SaveAs(mFileName,mbCompress,mbAddToHistory);
+      return context.project.SaveAs(mFileName,mbCompress,mbAddToHistory);
 }

src/commands/ScreenshotCommand.cpp

@@ -20,6 +20,8 @@ small calculations of rectangles.
 #include "../Audacity.h"
 #include "ScreenshotCommand.h"
 
+#include <mutex>
+
 #include "../Project.h"
 #include <wx/toplevel.h>
 #include <wx/dcscreen.h>
@@ -31,6 +33,7 @@ small calculations of rectangles.
 
 #include "../AdornedRulerPanel.h"
 #include "../TrackPanel.h"
+#include "../effects/Effect.h"
 #include "../toolbars/ToolManager.h"
 #include "../Prefs.h"
 #include "../Shuttle.h"
@@ -87,7 +90,19 @@ kBackgroundStrings[ ScreenshotCommand::nBackgrounds ] =
 };
 
 
-bool ScreenshotCommand::DefineParams( ShuttleParams & S ){ 
+ScreenshotCommand::ScreenshotCommand()
+{
+   mbBringToTop=true;
+   mIgnore=NULL;
+   
+   static std::once_flag flag;
+   std::call_once( flag, []{
+      AudacityCommand::SetVetoDialogHook( MayCapture );
+      Effect::SetVetoDialogHook( MayCapture );
+   });
+}
+
+bool ScreenshotCommand::DefineParams( ShuttleParams & S ){
    S.Define(                               mPath,        wxT("Path"),         wxT(""));
    S.DefineEnum(                           mWhat,        wxT("CaptureWhat"),  kwindow,kCaptureWhatStrings, nCaptureWhats );
    S.DefineEnum(                           mBack,        wxT("Background"),   kNone, kBackgroundStrings, nBackgrounds );
@@ -579,7 +594,7 @@ void ScreenshotCommand::CaptureScriptables(
 
 void ScreenshotCommand::CaptureCommands( 
    const CommandContext & context, const wxArrayStringEx & Commands ){
-   AudacityProject * pProject = context.GetProject();
+   AudacityProject * pProject = &context.project;
    CommandManager * pMan = pProject->GetCommandManager();
    wxString Str;
    // Yucky static variables.  Is there a better way?  The problem is that we need the
@@ -792,16 +807,16 @@ bool ScreenshotCommand::Apply(const CommandContext & context)
    GetDerivedParams();
    //Don't reset the toolbars to a known state.
    //We will be capturing variations of them.
-   //context.GetProject()->GetToolManager()->Reset();
+   //context.project.GetToolManager()->Reset();
 
-   wxTopLevelWindow *w = GetFrontWindow(context.GetProject());
+   wxTopLevelWindow *w = GetFrontWindow(&context.project);
    if (!w)
       return false;
 
-   TrackPanel *panel = context.GetProject()->GetTrackPanel();
+   TrackPanel *panel = context.project.GetTrackPanel();
    AdornedRulerPanel *ruler = panel->mRuler;
 
-   int nTracks = context.GetProject()->GetTracks()->size();
+   int nTracks = context.project.GetTracks()->size();
 
    int x1,y1,x2,y2;
    w->ClientToScreen(&x1, &y1);
@@ -811,47 +826,47 @@ bool ScreenshotCommand::Apply(const CommandContext & context)
 
    switch (mCaptureMode) {
    case kwindow:
-      return Capture(context,  WindowFileName( context.GetProject(), w ) , w, GetWindowRect(w));
+      return Capture(context,  WindowFileName( &context.project, w ) , w, GetWindowRect(w));
    case kfullwindow:
    case kwindowplus:
-      return Capture(context,  WindowFileName( context.GetProject(), w ) , w, GetFullWindowRect(w));
+      return Capture(context,  WindowFileName( &context.project, w ) , w, GetFullWindowRect(w));
    case kfullscreen:
       return Capture(context, mFileName, w,GetScreenRect());
    case ktoolbars:
-      return CaptureDock(context, context.GetProject()->GetToolManager()->GetTopDock(), mFileName);
+      return CaptureDock(context, context.project.GetToolManager()->GetTopDock(), mFileName);
    case kscriptables:
-      CaptureScriptables(context, context.GetProject(), mFileName);
+      CaptureScriptables(context, &context.project, mFileName);
       break;
    case keffects:
-      CaptureEffects(context, context.GetProject(), mFileName);
+      CaptureEffects(context, &context.project, mFileName);
       break;
    case kpreferences:
-      CapturePreferences(context, context.GetProject(), mFileName);
+      CapturePreferences(context, &context.project, mFileName);
       break;
    case kselectionbar:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), SelectionBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), SelectionBarID, mFileName);
    case kspectralselection:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), SpectralSelectionBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), SpectralSelectionBarID, mFileName);
    case ktools:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), ToolsBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), ToolsBarID, mFileName);
    case ktransport:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), TransportBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), TransportBarID, mFileName);
    case kmixer:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), MixerBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), MixerBarID, mFileName);
    case kmeter:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), MeterBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), MeterBarID, mFileName);
    case krecordmeter:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), RecordMeterBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), RecordMeterBarID, mFileName);
    case kplaymeter:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), PlayMeterBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), PlayMeterBarID, mFileName);
    case kedit:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), EditBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), EditBarID, mFileName);
    case kdevice:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), DeviceBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), DeviceBarID, mFileName);
    case ktranscription:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), TranscriptionBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), TranscriptionBarID, mFileName);
    case kscrub:
-      return CaptureToolbar(context, context.GetProject()->GetToolManager(), ScrubbingBarID, mFileName);
+      return CaptureToolbar(context, context.project.GetToolManager(), ScrubbingBarID, mFileName);
    case ktrackpanel:
       return Capture(context, mFileName, panel, GetPanelRect(panel));
    case kruler:
@@ -859,9 +874,9 @@ bool ScreenshotCommand::Apply(const CommandContext & context)
    case ktracks:
       return Capture(context, mFileName, panel, GetTracksRect(panel));
    case kfirsttrack:
-      return Capture(context, mFileName, panel, GetTrackRect( context.GetProject(), panel, 0 ) );
+      return Capture(context, mFileName, panel, GetTrackRect( &context.project, panel, 0 ) );
    case ksecondtrack:
-      return Capture(context, mFileName, panel, GetTrackRect( context.GetProject(), panel, 1 ) );
+      return Capture(context, mFileName, panel, GetTrackRect( &context.project, panel, 1 ) );
    case ktracksplus:
    {  wxRect r = GetTracksRect(panel);
       r.SetTop( r.GetTop() - ruler->GetRulerHeight() );
@@ -869,36 +884,36 @@ bool ScreenshotCommand::Apply(const CommandContext & context)
       return Capture(context, mFileName, panel, r);
    }
    case kfirsttrackplus:
-   {  wxRect r = GetTrackRect(context.GetProject(), panel, 0 );
+   {  wxRect r = GetTrackRect(&context.project, panel, 0 );
       r.SetTop( r.GetTop() - ruler->GetRulerHeight() );
       r.SetHeight( r.GetHeight() + ruler->GetRulerHeight() );
       return Capture(context, mFileName, panel, r );
    }
    case kfirsttwotracks:
-   {  wxRect r = GetTrackRect( context.GetProject(), panel, 0 );
+   {  wxRect r = GetTrackRect( &context.project, panel, 0 );
-      r = r.Union( GetTrackRect( context.GetProject(), panel, 1 ));
+      r = r.Union( GetTrackRect( &context.project, panel, 1 ));
       return Capture(context, mFileName, panel, r );
    }
    case kfirstthreetracks:
-   {  wxRect r = GetTrackRect( context.GetProject(), panel, 0 );
+   {  wxRect r = GetTrackRect( &context.project, panel, 0 );
-      r = r.Union( GetTrackRect( context.GetProject(), panel, 2 ));
+      r = r.Union( GetTrackRect( &context.project, panel, 2 ));
       return Capture(context, mFileName, panel, r );
    }
    case kfirstfourtracks:
-   {  wxRect r = GetTrackRect( context.GetProject(), panel, 0 );
+   {  wxRect r = GetTrackRect( &context.project, panel, 0 );
-      r = r.Union( GetTrackRect( context.GetProject(), panel, 3 ));
+      r = r.Union( GetTrackRect( &context.project, panel, 3 ));
       return Capture(context, mFileName, panel, r );
    }
    case kalltracks:
-   {  wxRect r = GetTrackRect( context.GetProject(), panel, 0 );
+   {  wxRect r = GetTrackRect( &context.project, panel, 0 );
-      r = r.Union( GetTrackRect( context.GetProject(), panel, nTracks-1 ));
+      r = r.Union( GetTrackRect( &context.project, panel, nTracks-1 ));
       return Capture(context, mFileName, panel, r );
    }
    case kalltracksplus:
-   {  wxRect r = GetTrackRect( context.GetProject(), panel, 0 );
+   {  wxRect r = GetTrackRect( &context.project, panel, 0 );
       r.SetTop( r.GetTop() - ruler->GetRulerHeight() );
       r.SetHeight( r.GetHeight() + ruler->GetRulerHeight() );
-      r = r.Union( GetTrackRect( context.GetProject(), panel, nTracks-1 ));
+      r = r.Union( GetTrackRect( &context.project, panel, nTracks-1 ));
       return Capture(context, mFileName, panel, r );
    }
    default:

src/commands/ScreenshotCommand.h

@@ -78,7 +78,7 @@ public:
       nCaptureWhats
    };
 
-   ScreenshotCommand(){ mbBringToTop=true;mIgnore=NULL;};
+   ScreenshotCommand();
    // ComponentInterface overrides
    ComponentInterfaceSymbol GetSymbol() override {return SCREENSHOT_PLUGIN_SYMBOL;};
    wxString GetDescription() override {return _("Takes screenshots.");};

src/commands/ScriptCommandRelay.cpp

@@ -24,8 +24,8 @@ code out of ModuleManager.
 #include "CommandTargets.h"
 #include "CommandBuilder.h"
 #include "AppCommandEvent.h"
-#include "../Project.h"
 #include <wx/app.h>
+#include <wx/window.h>
 #include <wx/string.h>
 
 // Declare static class members
@@ -52,13 +52,16 @@ void ScriptCommandRelay::Run()
 }
 
 /// Send a command to a project, to be applied in that context.
-void ScriptCommandRelay::PostCommand(AudacityProject *project, const OldStyleCommandPointer &cmd)
+void ScriptCommandRelay::PostCommand(
+   wxWindow *pWindow, const OldStyleCommandPointer &cmd)
 {
-   wxASSERT(project != NULL);
+   wxASSERT( pWindow );
    wxASSERT(cmd != NULL);
-   AppCommandEvent ev;
+   if ( pWindow ) {
-   ev.SetCommand(cmd);
+      AppCommandEvent ev;
-   project->GetEventHandler()->AddPendingEvent(ev);
+      ev.SetCommand(cmd);
+      pWindow->GetEventHandler()->AddPendingEvent(ev);
+   }
 }
 
 /// This is the function which actually obeys one command.  Rather than applying
@@ -71,9 +74,8 @@ int ExecCommand(wxString *pIn, wxString *pOut)
       CommandBuilder builder(*pIn);
       if (builder.WasValid())
       {
-         AudacityProject *project = GetActiveProject();
          OldStyleCommandPointer cmd = builder.GetCommand();
-         ScriptCommandRelay::PostCommand(project, cmd);
+         ScriptCommandRelay::PostCommand(wxTheApp->GetTopWindow(), cmd);
 
          *pOut = wxEmptyString;
       }

src/commands/ScriptCommandRelay.h

@@ -20,11 +20,11 @@
 
 #include "../MemoryX.h"
 
+class wxWindow;
 class CommandHandler;
 class ResponseQueue;
 class Response;
 class ResponseQueueTarget;
-class AudacityProject;
 class OldStyleCommand;
 using OldStyleCommandPointer = std::shared_ptr<OldStyleCommand>;
 class wxString;
@@ -50,7 +50,8 @@ class ScriptCommandRelay
       static void SetCommandHandler(CommandHandler &ch);
 
       static void Run();
-      static void PostCommand(AudacityProject *project, const OldStyleCommandPointer &cmd);
+      static void PostCommand(
+         wxWindow *pWindow, const OldStyleCommandPointer &cmd);
       static void SendResponse(const wxString &response);
       static Response ReceiveResponse();
       static std::shared_ptr<ResponseQueueTarget> GetResponseTarget();

src/commands/SelectCommand.cpp

@@ -85,7 +85,7 @@ void SelectTimeCommand::PopulateOrExchange(ShuttleGui & S)
 bool SelectTimeCommand::Apply(const CommandContext & context){
    // Many commands need focus on track panel.
    // No harm in setting it with a scripted select.
-   context.GetProject()->GetTrackPanel()->SetFocus();
+   context.project.GetTrackPanel()->SetFocus();
    if( !bHasT0 && !bHasT1 )
       return true;
 
@@ -97,7 +97,7 @@ bool SelectTimeCommand::Apply(const CommandContext & context){
    if( !bHasRelativeSpec )
       mRelativeTo = 0;
 
-   AudacityProject * p = context.GetProject();
+   AudacityProject * p = &context.project;
    double end = p->GetTracks()->GetEndTime();
    double t0;
    double t1;
@@ -164,7 +164,7 @@ bool SelectFrequenciesCommand::Apply(const CommandContext & context){
    if( !bHasBottom )
       mBottom = 0.0;
 
-   context.GetProject()->SSBL_ModifySpectralSelection(
+   context.project.SSBL_ModifySpectralSelection(
       mBottom, mTop, false);// false for not done.
    return true;
 }
@@ -214,7 +214,7 @@ bool SelectTracksCommand::Apply(const CommandContext &context)
    // Used to invalidate cached selection and tracks.
    Effect::IncEffectCounter();
    int index = 0;
-   TrackList *tracks = context.GetProject()->GetTracks();
+   TrackList *tracks = context.project.GetTracks();
 
    // Defaults if no value...
    if( !bHasNumTracks ) 

src/commands/SetLabelCommand.cpp

@@ -66,8 +66,8 @@ bool SetLabelCommand::Apply(const CommandContext & context)
    // this code could be put in subroutines/reduced.
 
    //wxString mode = GetString(wxT("Type"));
-   AudacityProject * p = context.GetProject();
+   AudacityProject * p = &context.project;
-   TrackList *tracks = context.GetProject()->GetTracks();
+   TrackList *tracks = context.project.GetTracks();
    LabelStruct * pLabel = NULL;
    int i=0;
    int nn=0;

src/commands/SetProjectCommand.cpp

@@ -66,7 +66,7 @@ void SetProjectCommand::PopulateOrExchange(ShuttleGui & S)
 
 bool SetProjectCommand::Apply(const CommandContext & context)
 {
-   AudacityProject * pProj = context.GetProject();
+   AudacityProject * pProj = &context.project;
    if( bHasName )
       pProj->SetLabel(mName);
 

src/commands/SetTrackInfoCommand.cpp

@@ -94,7 +94,7 @@ bool SetTrackBase::Apply(const CommandContext & context  )
 {
    long i = 0;// track counter
    long j = 0;// channel counter
-   auto tracks = context.GetProject()->GetTracks();
+   auto tracks = context.project.GetTracks();
    for ( auto t : tracks->Leaders() )
    {
       auto channels = TrackList::Channels(t);
@@ -163,7 +163,7 @@ bool SetTrackStatusCommand::ApplyInner(const CommandContext & context, Track * t
    if( !bIsSecondChannel ){
       if( bHasFocused )
       {
-         TrackPanel *panel = context.GetProject()->GetTrackPanel();
+         TrackPanel *panel = context.project.GetTrackPanel();
          if( bFocused)
             panel->SetFocusedTrack( t );
          else if( t== panel->GetFocusedTrack() )

src/effects/Effect.cpp

@@ -59,6 +59,7 @@ greater use in future.
 #include "../ShuttleGui.h"
 #include "../Shuttle.h"
 #include "../WaveTrack.h"
+#include "../commands/Command.h"
 #include "../toolbars/ControlToolBar.h"
 #include "../widgets/AButton.h"
 #include "../widgets/ProgressDialog.h"
@@ -76,8 +77,6 @@ greater use in future.
 #include <Cocoa/Cocoa.h>
 #endif
 
-#include "../commands/ScreenshotCommand.h"
-
 #include <unordered_map>
 
 // Effect application counter
@@ -109,6 +108,25 @@ const wxString Effect::kFactoryDefaultsIdent = wxT("<Factory Defaults>");
 
 using t2bHash = std::unordered_map< void*, bool >;
 
+namespace {
+
+Effect::VetoDialogHook &GetVetoDialogHook()
+{
+   static Effect::VetoDialogHook sHook = nullptr;
+   return sHook;
+}
+
+}
+
+auto Effect::SetVetoDialogHook( VetoDialogHook hook )
+   -> VetoDialogHook
+{
+   auto &theHook = GetVetoDialogHook();
+   auto result = theHook;
+   theHook = hook;
+   return result;
+}
+
 Effect::Effect()
 {
    mClient = NULL;
@@ -556,7 +574,8 @@ bool Effect::ShowInterface(wxWindow *parent, bool forceModal)
    mUIDialog->Fit();
    mUIDialog->SetMinSize(mUIDialog->GetSize());
 
-   if( ScreenshotCommand::MayCapture( mUIDialog ) )
+   auto hook = GetVetoDialogHook();
+   if( hook && hook( mUIDialog ) )
       return false;
 
    if( SupportsRealtime() && !forceModal )
@@ -3303,7 +3322,9 @@ void EffectUIHost::OnApply(wxCommandEvent & evt)
    if( mEffect )
       mEffect->Apply();
    if( mCommand )
-      mCommand->Apply();
+      // PRL:  I don't like the global and would rather pass *mProject!
+      // But I am preserving old behavior
+      mCommand->Apply( CommandContext{ *GetActiveProject() } );
 }
 
 void EffectUIHost::DoCancel()

src/effects/Effect.h

@@ -72,6 +72,11 @@ class AUDACITY_DLL_API Effect /* not final */ : public wxEvtHandler,
    Effect();
    virtual ~Effect();
 
+   // Type of a registered function that, if it returns true,
+   // causes ShowInterface to return early without making any dialog
+   using VetoDialogHook = bool (*) ( wxDialog* );
+   static VetoDialogHook SetVetoDialogHook( VetoDialogHook hook );
+
    // ComponentInterface implementation
 
    PluginPath GetPath() override;

src/effects/EffectManager.cpp

@@ -35,6 +35,7 @@ effects.
 
 #include "../ShuttleGetDefinition.h"
 #include "../commands/CommandContext.h"
+#include "../commands/Command.h"
 #include "../PluginManager.h"