audacity/src/effects/Effect.cpp

/**********************************************************************

  Audacity: A Digital Audio Editor

  Effect.cpp

  Dominic Mazzoni
  Vaughan Johnson
  Martyn Shaw

*******************************************************************//**

\class Effect
\brief Base class for many of the effects in Audacity.

*//****************************************************************//**

\class EffectDialog
\brief New (Jun-2006) base class for effects dialogs.  Likely to get
greater use in future.

*//*******************************************************************/

#include "../Audacity.h"
#include "Effect.h"

#include <algorithm>

#include <wx/defs.h>
#include <wx/hashmap.h>
#include <wx/msgdlg.h>
#include <wx/sizer.h>
#include <wx/stockitem.h>
#include <wx/string.h>
#include <wx/tglbtn.h>
#include <wx/timer.h>
#include <wx/utils.h>
#include <wx/log.h>

#include "audacity/ConfigInterface.h"

#include "../AudacityException.h"
#include "../AudioIO.h"
#include "../LabelTrack.h"
#include "../Mix.h"
#include "../Prefs.h"
#include "../Project.h"
#include "../ShuttleGui.h"
#include "../WaveTrack.h"
#include "../toolbars/ControlToolBar.h"
#include "../widgets/AButton.h"
#include "../widgets/ProgressDialog.h"
#include "../ondemand/ODManager.h"
#include "TimeWarper.h"
#include "nyquist/Nyquist.h"

#if defined(__WXMAC__)
#include <Cocoa/Cocoa.h>
#endif

#include "../Experimental.h"

static const int kDummyID = 20000;
static const int kSaveAsID = 20001;
static const int kImportID = 20002;
static const int kExportID = 20003;
static const int kDefaultsID = 20004;
static const int kOptionsID = 20005;
static const int kUserPresetsDummyID = 20006;
static const int kDeletePresetDummyID = 20007;
static const int kMenuID = 20100;
static const int kEnableID = 20101;
static const int kPlayID = 20102;
static const int kRewindID = 20103;
static const int kFFwdID = 20104;
static const int kPlaybackID = 20105;
static const int kCaptureID = 20106;
static const int kUserPresetsID = 21000;
static const int kDeletePresetID = 22000;
static const int kFactoryPresetsID = 23000;

const wxString Effect::kUserPresetIdent = wxT("User Preset:");
const wxString Effect::kFactoryPresetIdent = wxT("Factory Preset:");
const wxString Effect::kCurrentSettingsIdent = wxT("<Current Settings>");
const wxString Effect::kFactoryDefaultsIdent = wxT("<Factory Defaults>");

WX_DECLARE_VOIDPTR_HASH_MAP( bool, t2bHash );

Effect::Effect()
{
   mClient = NULL;

   mTracks = NULL;
   mOutputTracksType = Track::None;
   mT0 = 0.0;
   mT1 = 0.0;
   mDuration = 0.0;
   mIsPreview = false;
   mIsLinearEffect = false;
   mPreviewWithNotSelected = false;
   mPreviewFullSelection = false;
   mNumTracks = 0;
   mNumGroups = 0;
   mProgress = NULL;

   mRealtimeSuspendLock.Enter();
   mRealtimeSuspendCount = 1;    // Effects are initially suspended
   mRealtimeSuspendLock.Leave();

   mUIParent = NULL;
   mUIDialog = NULL;

   mNumAudioIn = 0;
   mNumAudioOut = 0;

   mBufferSize = 0;
   mBlockSize = 0;
   mNumChannels = 0;

   mUIDebug = false;

   AudacityProject *p = GetActiveProject();
   mProjectRate = p ? p->GetRate() : 44100;

   mIsBatch = false;
}

Effect::~Effect()
{
   if (mUIDialog)
   {
      mUIDialog->Close();
   }
}

// EffectIdentInterface implementation

EffectType Effect::GetType()
{
   if (mClient)
   {
      return mClient->GetType();
   }

   return EffectTypeNone;
}

wxString Effect::GetPath()
{
   if (mClient)
   {
      return mClient->GetPath();
   }

   return BUILTIN_EFFECT_PREFIX + GetSymbol();
}

wxString Effect::GetSymbol()
{
   if (mClient)
   {
      return mClient->GetSymbol();
   }

   return wxEmptyString;
}

wxString Effect::GetName()
{
   if (mClient)
   {
      return mClient->GetName();
   }

   return GetSymbol();
}

wxString Effect::GetVendor()
{
   if (mClient)
   {
      return mClient->GetVendor();
   }

   return XO("Audacity");
}

wxString Effect::GetVersion()
{
   if (mClient)
   {
      return mClient->GetVersion();
   }

   return AUDACITY_VERSION_STRING;
}

wxString Effect::GetDescription()
{
   if (mClient)
   {
      return mClient->GetDescription();
   }

   return wxEmptyString;
}

wxString Effect::GetFamily()
{
   if (mClient)
   {
      return mClient->GetFamily();
   }

   return XO("Audacity");
}

bool Effect::IsInteractive()
{
   if (mClient)
   {
      return mClient->IsInteractive();
   }

   return true;
}

bool Effect::IsDefault()
{
   if (mClient)
   {
      return mClient->IsDefault();
   }

   return true;
}

bool Effect::IsLegacy() 
{
   if (mClient)
   {
      return false;
   }

   return true;
}

bool Effect::SupportsRealtime()
{
   if (mClient)
   {
      return mClient->SupportsRealtime();
   }

   return false;
}

bool Effect::SupportsAutomation()
{
   if (mClient)
   {
      return mClient->SupportsAutomation();
   }

   return true;
}

// EffectClientInterface implementation

bool Effect::SetHost(EffectHostInterface *host)
{
   if (mClient)
   {
      return mClient->SetHost(host);
   }

   return true;
}

unsigned Effect::GetAudioInCount()
{
   if (mClient)
   {
      return mClient->GetAudioInCount();
   }

   return 0;
}

unsigned Effect::GetAudioOutCount()
{
   if (mClient)
   {
      return mClient->GetAudioOutCount();
   }

   return 0;
}

int Effect::GetMidiInCount()
{
   if (mClient)
   {
      return mClient->GetMidiInCount();
   }

   return 0;
}

int Effect::GetMidiOutCount()
{
   if (mClient)
   {
      return mClient->GetMidiOutCount();
   }

   return 0;
}

void Effect::SetSampleRate(double rate)
{
   if (mClient)
   {
      mClient->SetSampleRate(rate);
   }

   mSampleRate = rate;
}

size_t Effect::SetBlockSize(size_t maxBlockSize)
{
   if (mClient)
   {
      return mClient->SetBlockSize(maxBlockSize);
   }

   mBlockSize = maxBlockSize;

   return mBlockSize;
}

sampleCount Effect::GetLatency()
{
   if (mClient)
   {
      return mClient->GetLatency();
   }

   return 0;
}

size_t Effect::GetTailSize()
{
   if (mClient)
   {
      return mClient->GetTailSize();
   }

   return 0;
}

bool Effect::IsReady()
{
   if (mClient)
   {
      return mClient->IsReady();
   }

   return true;
}

bool Effect::ProcessInitialize(sampleCount totalLen, ChannelNames chanMap)
{
   if (mClient)
   {
      return mClient->ProcessInitialize(totalLen, chanMap);
   }

   return true;
}

bool Effect::ProcessFinalize()
{
   if (mClient)
   {
      return mClient->ProcessFinalize();
   }

   return true;
}

size_t Effect::ProcessBlock(float **inBlock, float **outBlock, size_t blockLen)
{
   if (mClient)
   {
      return mClient->ProcessBlock(inBlock, outBlock, blockLen);
   }

   return 0;
}

bool Effect::RealtimeInitialize()
{
   if (mClient)
   {
      mBlockSize = mClient->SetBlockSize(512);
      return mClient->RealtimeInitialize();
   }

   mBlockSize = 512;

   return false;
}

bool Effect::RealtimeAddProcessor(unsigned numChannels, float sampleRate)
{
   if (mClient)
   {
      return mClient->RealtimeAddProcessor(numChannels, sampleRate);
   }

   return true;
}

bool Effect::RealtimeFinalize()
{
   if (mClient)
   {
      return mClient->RealtimeFinalize();
   }

   return false;
}

bool Effect::RealtimeSuspend()
{
   if (mClient)
   {
      if (mClient->RealtimeSuspend())
      {
         mRealtimeSuspendLock.Enter();
         mRealtimeSuspendCount++;
         mRealtimeSuspendLock.Leave();
         return true;
      }

      return false;
   }

   mRealtimeSuspendLock.Enter();
   mRealtimeSuspendCount++;
   mRealtimeSuspendLock.Leave();

   return true;
}

bool Effect::RealtimeResume()
{
   if (mClient)
   {
      if (mClient->RealtimeResume())
      {
         mRealtimeSuspendLock.Enter();
         mRealtimeSuspendCount--;
         mRealtimeSuspendLock.Leave();
         return true;
      }

      return false;
   }

   mRealtimeSuspendLock.Enter();
   mRealtimeSuspendCount--;
   mRealtimeSuspendLock.Leave();

   return true;
}

bool Effect::RealtimeProcessStart()
{
   if (mClient)
   {
      return mClient->RealtimeProcessStart();
   }

   return true;
}

size_t Effect::RealtimeProcess(int group,
                                    float **inbuf,
                                    float **outbuf,
                                    size_t numSamples)
{
   if (mClient)
   {
      return mClient->RealtimeProcess(group, inbuf, outbuf, numSamples);
   }

   return 0;
}

bool Effect::RealtimeProcessEnd()
{
   if (mClient)
   {
      return mClient->RealtimeProcessEnd();
   }

   return true;
}

bool Effect::ShowInterface(wxWindow *parent, bool forceModal)
{
   if (!IsInteractive())
   {
      return true;
   }

   if (mUIDialog)
   {
      if ( mUIDialog->Close(true) )
         mUIDialog = nullptr;
      return false;
   }

   if (mClient)
   {
      return mClient->ShowInterface(parent, forceModal);
   }

   // mUIDialog is null
   auto cleanup = valueRestorer( mUIDialog );
   
   mUIDialog = CreateUI(parent, this);
   if (!mUIDialog)
   {
      return false;
   }

   mUIDialog->Layout();
   mUIDialog->Fit();
   mUIDialog->SetMinSize(mUIDialog->GetSize());

   if (SupportsRealtime() && !forceModal)
   {
      mUIDialog->Show();
      cleanup.release();

      // Return false to bypass effect processing
      return false;
   }

   bool res = mUIDialog->ShowModal() != 0;

   return res;
}

bool Effect::GetAutomationParameters(EffectAutomationParameters & parms)
{
   if (mClient)
   {
      return mClient->GetAutomationParameters(parms);
   }

   return true;
}

bool Effect::SetAutomationParameters(EffectAutomationParameters & parms)
{
   if (mClient)
   {
      return mClient->SetAutomationParameters(parms);
   }

   return true;
}

bool Effect::LoadUserPreset(const wxString & name)
{
   if (mClient)
   {
      return mClient->LoadUserPreset(name);
   }

   wxString parms;
   if (!GetPrivateConfig(name, wxT("Parameters"), parms))
   {
      return false;
   }

   return SetAutomationParameters(parms);
}

bool Effect::SaveUserPreset(const wxString & name)
{
   if (mClient)
   {
      return mClient->SaveUserPreset(name);
   }

   wxString parms;
   if (!GetAutomationParameters(parms))
   {
      return false;
   }

   return SetPrivateConfig(name, wxT("Parameters"), parms);
}

wxArrayString Effect::GetFactoryPresets()
{
   if (mClient)
   {
      return mClient->GetFactoryPresets();
   }

   return wxArrayString();
}

bool Effect::LoadFactoryPreset(int id)
{
   if (mClient)
   {
      return mClient->LoadFactoryPreset(id);
   }

   return true;
}

bool Effect::LoadFactoryDefaults()
{
   if (mClient)
   {
      return mClient->LoadFactoryDefaults();
   }

   return LoadUserPreset(GetFactoryDefaultsGroup());
}

// EffectUIClientInterface implementation

void Effect::SetHostUI(EffectUIHostInterface *WXUNUSED(host))
{
}

bool Effect::PopulateUI(wxWindow *parent)
{
   mUIParent = parent;
   mUIParent->PushEventHandler(this);

//   LoadUserPreset(GetCurrentSettingsGroup());

   ShuttleGui S(mUIParent, eIsCreating);
   PopulateOrExchange(S);

   mUIParent->SetMinSize(mUIParent->GetSizer()->GetMinSize());

   return true;
}

bool Effect::IsGraphicalUI()
{
   return false;
}

bool Effect::ValidateUI()
{
   return mUIParent->Validate();
}

bool Effect::HideUI()
{
   return true;
}

bool Effect::CloseUI()
{
   if (mUIParent)
      mUIParent->RemoveEventHandler(this);

   mUIParent = NULL;
   mUIDialog = NULL;

   return true;
}

bool Effect::CanExportPresets()
{
   return false;
}

void Effect::ExportPresets()
{
}

void Effect::ImportPresets()
{
}

bool Effect::HasOptions()
{
   return false;
}

void Effect::ShowOptions()
{
}

// EffectHostInterface implementation

double Effect::GetDefaultDuration()
{
   return 30.0;
}

double Effect::GetDuration()
{
   if (mDuration < 0.0)
   {
      mDuration = 0.0;
   }

   return mDuration;
}

wxString Effect::GetDurationFormat()
{
   return mDurationFormat;
}

wxString Effect::GetSelectionFormat()
{
   return GetActiveProject()->GetSelectionFormat();
}

void Effect::SetDuration(double seconds)
{
   if (seconds < 0.0)
   {
      seconds = 0.0;
   }

   if (GetType() == EffectTypeGenerate)
   {
      SetPrivateConfig(GetCurrentSettingsGroup(), wxT("LastUsedDuration"), seconds);
   }

   mDuration = seconds;

   mIsSelection = false;

   return;
}

bool Effect::Apply()
{
   // This is absolute hackage...but easy and I can't think of another way just now.
   //
   // It should callback to the EffectManager to kick off the processing
   return GetActiveProject()->OnEffect(GetID(), AudacityProject::OnEffectFlags::kConfigured);
}

void Effect::Preview()
{
   Preview(false);
}

wxDialog *Effect::CreateUI(wxWindow *parent, EffectUIClientInterface *client)
{
   Destroy_ptr<EffectUIHost> dlg
      { safenew EffectUIHost{ parent, this, client} };

   if (dlg->Initialize())
   {
      // release() is safe because parent will own it
      return dlg.release();
   }

   return NULL;
}

wxString Effect::GetUserPresetsGroup(const wxString & name)
{
   wxString group = wxT("UserPresets");
   if (!name.IsEmpty())
   {
      group += wxCONFIG_PATH_SEPARATOR + name;
   }

   return group;
}

wxString Effect::GetCurrentSettingsGroup()
{
   return wxT("CurrentSettings");
}

wxString Effect::GetFactoryDefaultsGroup()
{
   return wxT("FactoryDefaults");
}

wxString Effect::GetSavedStateGroup()
{
   return wxT("SavedState");
}

// ConfigClientInterface implementation
bool Effect::HasSharedConfigGroup(const wxString & group)
{
   return PluginManager::Get().HasSharedConfigGroup(GetID(), group);
}

bool Effect::GetSharedConfigSubgroups(const wxString & group, wxArrayString & subgroups)
{
   return PluginManager::Get().GetSharedConfigSubgroups(GetID(), group, subgroups);
}

bool Effect::GetSharedConfig(const wxString & group, const wxString & key, wxString & value, const wxString & defval)
{
   return PluginManager::Get().GetSharedConfig(GetID(), group, key, value, defval);
}

bool Effect::GetSharedConfig(const wxString & group, const wxString & key, int & value, int defval)
{
   return PluginManager::Get().GetSharedConfig(GetID(), group, key, value, defval);
}

bool Effect::GetSharedConfig(const wxString & group, const wxString & key, bool & value, bool defval)
{
   return PluginManager::Get().GetSharedConfig(GetID(), group, key, value, defval);
}

bool Effect::GetSharedConfig(const wxString & group, const wxString & key, float & value, float defval)
{
   return PluginManager::Get().GetSharedConfig(GetID(), group, key, value, defval);
}

bool Effect::GetSharedConfig(const wxString & group, const wxString & key, double & value, double defval)
{
   return PluginManager::Get().GetSharedConfig(GetID(), group, key, value, defval);
}

bool Effect::SetSharedConfig(const wxString & group, const wxString & key, const wxString & value)
{
   return PluginManager::Get().SetSharedConfig(GetID(), group, key, value);
}

bool Effect::SetSharedConfig(const wxString & group, const wxString & key, const int & value)
{
   return PluginManager::Get().SetSharedConfig(GetID(), group, key, value);
}

bool Effect::SetSharedConfig(const wxString & group, const wxString & key, const bool & value)
{
   return PluginManager::Get().SetSharedConfig(GetID(), group, key, value);
}

bool Effect::SetSharedConfig(const wxString & group, const wxString & key, const float & value)
{
   return PluginManager::Get().SetSharedConfig(GetID(), group, key, value);
}

bool Effect::SetSharedConfig(const wxString & group, const wxString & key, const double & value)
{
   return PluginManager::Get().SetSharedConfig(GetID(), group, key, value);
}

bool Effect::RemoveSharedConfigSubgroup(const wxString & group)
{
   return PluginManager::Get().RemoveSharedConfigSubgroup(GetID(), group);
}

bool Effect::RemoveSharedConfig(const wxString & group, const wxString & key)
{
   return PluginManager::Get().RemoveSharedConfig(GetID(), group, key);
}

bool Effect::HasPrivateConfigGroup(const wxString & group)
{
   return PluginManager::Get().HasPrivateConfigGroup(GetID(), group);
}

bool Effect::GetPrivateConfigSubgroups(const wxString & group, wxArrayString & subgroups)
{
   return PluginManager::Get().GetPrivateConfigSubgroups(GetID(), group, subgroups);
}

bool Effect::GetPrivateConfig(const wxString & group, const wxString & key, wxString & value, const wxString & defval)
{
   return PluginManager::Get().GetPrivateConfig(GetID(), group, key, value, defval);
}

bool Effect::GetPrivateConfig(const wxString & group, const wxString & key, int & value, int defval)
{
   return PluginManager::Get().GetPrivateConfig(GetID(), group, key, value, defval);
}

bool Effect::GetPrivateConfig(const wxString & group, const wxString & key, bool & value, bool defval)
{
   return PluginManager::Get().GetPrivateConfig(GetID(), group, key, value, defval);
}

bool Effect::GetPrivateConfig(const wxString & group, const wxString & key, float & value, float defval)
{
   return PluginManager::Get().GetPrivateConfig(GetID(), group, key, value, defval);
}

bool Effect::GetPrivateConfig(const wxString & group, const wxString & key, double & value, double defval)
{
   return PluginManager::Get().GetPrivateConfig(GetID(), group, key, value, defval);
}

bool Effect::SetPrivateConfig(const wxString & group, const wxString & key, const wxString & value)
{
   return PluginManager::Get().SetPrivateConfig(GetID(), group, key, value);
}

bool Effect::SetPrivateConfig(const wxString & group, const wxString & key, const int & value)
{
   return PluginManager::Get().SetPrivateConfig(GetID(), group, key, value);
}

bool Effect::SetPrivateConfig(const wxString & group, const wxString & key, const bool & value)
{
   return PluginManager::Get().SetPrivateConfig(GetID(), group, key, value);
}

bool Effect::SetPrivateConfig(const wxString & group, const wxString & key, const float & value)
{
   return PluginManager::Get().SetPrivateConfig(GetID(), group, key, value);
}

bool Effect::SetPrivateConfig(const wxString & group, const wxString & key, const double & value)
{
   return PluginManager::Get().SetPrivateConfig(GetID(), group, key, value);
}

bool Effect::RemovePrivateConfigSubgroup(const wxString & group)
{
   return PluginManager::Get().RemovePrivateConfigSubgroup(GetID(), group);
}

bool Effect::RemovePrivateConfig(const wxString & group, const wxString & key)
{
   return PluginManager::Get().RemovePrivateConfig(GetID(), group, key);
}

// Effect implementation

PluginID Effect::GetID()
{
   if (mClient)
   {
      return PluginManager::GetID(mClient);
   }

   return PluginManager::GetID(this);
}

bool Effect::Startup(EffectClientInterface *client)
{
   // Let destructor know we need to be shutdown
   mClient = client;

   // Set host so client startup can use our services
   if (!SetHost(this))
   {
      // Bail if the client startup fails
      mClient = NULL;
      return false;
   }

   mNumAudioIn = GetAudioInCount();
   mNumAudioOut = GetAudioOutCount();

   bool haveDefaults;
   GetPrivateConfig(GetFactoryDefaultsGroup(), wxT("Initialized"), haveDefaults, false);
   if (!haveDefaults)
   {
      SaveUserPreset(GetFactoryDefaultsGroup());
      SetPrivateConfig(GetFactoryDefaultsGroup(), wxT("Initialized"), true);
   }
   LoadUserPreset(GetCurrentSettingsGroup());

   return Startup();
}

bool Effect::Startup()
{
   return true;
}

bool Effect::GetAutomationParameters(wxString & parms)
{
   EffectAutomationParameters eap;

   if (mUIDialog && !TransferDataFromWindow())
   {
      return false;
   }

   if (!GetAutomationParameters(eap))
   {
      return false;
   }

   return eap.GetParameters(parms);
}

bool Effect::SetAutomationParameters(const wxString & parms)
{
   wxString preset = parms;
   bool success = false;
   if (preset.StartsWith(kUserPresetIdent))
   {
      preset.Replace(kUserPresetIdent, wxEmptyString, false);
      success = LoadUserPreset(GetUserPresetsGroup(preset));
   }
   else if (preset.StartsWith(kFactoryPresetIdent))
   {
      preset.Replace(kFactoryPresetIdent, wxEmptyString, false);
      wxArrayString presets = GetFactoryPresets();
      success = LoadFactoryPreset(presets.Index(preset));
   }
   else if (preset.StartsWith(kCurrentSettingsIdent))
   {
      preset.Replace(kCurrentSettingsIdent, wxEmptyString, false);
      success = LoadUserPreset(GetCurrentSettingsGroup());
   }
   else if (preset.StartsWith(kFactoryDefaultsIdent))
   {
      preset.Replace(kFactoryDefaultsIdent, wxEmptyString, false);
      success = LoadUserPreset(GetFactoryDefaultsGroup());
   }
   else
   {
      EffectAutomationParameters eap(parms);
      success = SetAutomationParameters(eap);
   }

   if (!success)
   {
      wxMessageBox(
         wxString::Format(
            _("%s: Could not load settings below. Default settings will be used.\n\n%s"),
            GetName().c_str(),
            preset.c_str()
         )
      );

      return false;
   }

   if (!mUIDialog)
   {
      return true;
   }

   return TransferDataToWindow();
}

wxArrayString Effect::GetUserPresets()
{
   wxArrayString presets;

   GetPrivateConfigSubgroups(GetUserPresetsGroup(wxEmptyString), presets);

   presets.Sort();

   return presets;
}

bool Effect::HasCurrentSettings()
{
   return HasPrivateConfigGroup(GetCurrentSettingsGroup());
}

bool Effect::HasFactoryDefaults()
{
   return HasPrivateConfigGroup(GetFactoryDefaultsGroup());
}

wxString Effect::GetPreset(wxWindow * parent, const wxString & parms)
{
   EffectPresetsDialog dlg(parent, this);
   dlg.Layout();
   dlg.Fit();
   dlg.SetSize(dlg.GetMinSize());
   dlg.CenterOnParent();
   dlg.SetSelected(parms);

   if (dlg.ShowModal())
   {
      return dlg.GetSelected();
   }

   return wxEmptyString;
}

bool Effect::IsBatchProcessing()
{
   return mIsBatch;
}

void Effect::SetBatchProcessing(bool start)
{
   mIsBatch = start;

   if (start)
   {
      SaveUserPreset(GetSavedStateGroup());
   }
   else
   {
      LoadUserPreset(GetSavedStateGroup());
   }
}

bool Effect::DoEffect(wxWindow *parent,
                      double projectRate,
                      TrackList *list,
                      TrackFactory *factory,
                      SelectedRegion *selectedRegion,
                      bool shouldPrompt /* = true */)
{
   wxASSERT(selectedRegion->duration() >= 0.0);

   mOutputTracks.reset();

   mFactory = factory;
   mProjectRate = projectRate;
   mTracks = list;
   
   bool isSelection = false;

   mDuration = 0.0;

   if (GetType() == EffectTypeGenerate)
   {
      GetPrivateConfig(GetCurrentSettingsGroup(), wxT("LastUsedDuration"), mDuration, GetDefaultDuration());
   }

   mT0 = selectedRegion->t0();
   mT1 = selectedRegion->t1();
   if (mT1 > mT0)
   {
      // there is a selection: let's fit in there...
      // MJS: note that this is just for the TTC and is independent of the track rate
      // but we do need to make sure we have the right number of samples at the project rate
      double quantMT0 = QUANTIZED_TIME(mT0, mProjectRate);
      double quantMT1 = QUANTIZED_TIME(mT1, mProjectRate);
      mDuration = quantMT1 - quantMT0;
      mT1 = mT0 + mDuration;

      isSelection = true;
   }

   mDurationFormat = isSelection ? _("hh:mm:ss + samples") : _("hh:mm:ss + milliseconds");

#ifdef EXPERIMENTAL_SPECTRAL_EDITING
   mF0 = selectedRegion->f0();
   mF1 = selectedRegion->f1();
   wxArrayString Names;
   if( mF0 != SelectedRegion::UndefinedFrequency )
      Names.Add(wxT("control-f0"));
   if( mF1 != SelectedRegion::UndefinedFrequency )
      Names.Add(wxT("control-f1"));
   SetPresetParameters( &Names, NULL );

#endif
   CountWaveTracks();

   // Note: Init may read parameters from preferences
   if (!Init())
   {
      return false;
   }

   // Prompting will be bypassed when applying an effect that has already 
   // been configured, e.g. repeating the last effect on a different selection.
   // Prompting may call Effect::Preview
   if (shouldPrompt && IsInteractive() && !PromptUser(parent))
   {
      return false;
   }

   auto cleanup = finally( [&] {
      End();

      // In case of failed effect, be sure to free memory.
      ReplaceProcessedTracks( false );
   } );

   bool returnVal = true;
   bool skipFlag = CheckWhetherSkipEffect();
   if (skipFlag == false)
   {
      ProgressDialog progress{
         GetName(),
         wxString::Format(_("Applying %s..."), GetName().c_str()),
         pdlgHideStopButton
      };
      auto vr = valueRestorer( mProgress, &progress );

      returnVal = Process();
   }

   if (returnVal)
   {
      selectedRegion->setTimes(mT0, mT1);
   }

   return returnVal;
}

bool Effect::Delegate( Effect &delegate,
   wxWindow *parent, SelectedRegion *selectedRegion, bool shouldPrompt)
{
   return delegate.DoEffect( parent, mProjectRate, mTracks, mFactory,
      selectedRegion, shouldPrompt );
}

// All legacy effects should have this overridden
bool Effect::Init()
{
   return true;
}

// Remove this method once NoiseReduction gets migrated
bool Effect::PromptUser(wxWindow *parent)
{
   return ShowInterface(parent, IsBatchProcessing());
}

int Effect::GetPass()
{
   return mPass;
}

bool Effect::InitPass1()
{
   return true;
}

bool Effect::InitPass2()
{
   return false;
}

bool Effect::Process()
{
   CopyInputTracks(Track::All);
   bool bGoodResult = true;

   // It's possible that the number of channels the effect expects changed based on
   // the parameters (the Audacity Reverb effect does when the stereo width is 0).
   mNumAudioIn = GetAudioInCount();
   mNumAudioOut = GetAudioOutCount();

   mPass = 1;
   if (InitPass1())
   {
      bGoodResult = ProcessPass();
      mPass = 2;
      if (bGoodResult && InitPass2())
      {
         bGoodResult = ProcessPass();
      }
   }

   ReplaceProcessedTracks(bGoodResult); 

   return bGoodResult;
}

bool Effect::ProcessPass()
{
   bool bGoodResult = true;
   bool isGenerator = GetType() == EffectTypeGenerate;

   FloatBuffers inBuffer, outBuffer;
   ArrayOf<float *> inBufPos, outBufPos;

   ChannelName map[3];

   mBufferSize = 0;
   mBlockSize = 0;

   TrackListIterator iter(mOutputTracks.get());
   int count = 0;
   bool clear = false;
   Track* t = iter.First();

   for (t = iter.First(); t; t = iter.Next())
   {
      if (t->GetKind() != Track::Wave || !t->GetSelected())
      {
         if (t->IsSyncLockSelected())
         {
            t->SyncLockAdjust(mT1, mT0 + mDuration);
         }
         continue;
      }

      WaveTrack *left = (WaveTrack *)t;
      WaveTrack *right;
      sampleCount len;
      sampleCount leftStart;
      sampleCount rightStart;

      if (!isGenerator)
      {
         GetSamples(left, &leftStart, &len);
         mSampleCnt = len;
      }
      else
      {
         len = 0;
         leftStart = 0;
         mSampleCnt = left->TimeToLongSamples(mDuration);
      }

      mNumChannels = 1;

      if (left->GetChannel() == Track::LeftChannel)
      {
         map[0] = ChannelNameFrontLeft;
      }
      else if (left->GetChannel() == Track::RightChannel)
      {
         map[0] = ChannelNameFrontRight;
      }
      else
      {
         map[0] = ChannelNameMono;
      }
      map[1] = ChannelNameEOL;

      right = NULL;
      rightStart = 0;
      if (left->GetLinked() && mNumAudioIn > 1)
      {
         // Assume linked track is wave
         right = static_cast<WaveTrack *>(iter.Next());
         if (!isGenerator)
         {
            GetSamples(right, &rightStart, &len);
         }
         clear = false;
         mNumChannels = 2;

         if (right->GetChannel() == Track::LeftChannel)
         {
            map[1] = ChannelNameFrontLeft;
         }
         else if (right->GetChannel() == Track::RightChannel)
         {
            map[1] = ChannelNameFrontRight;
         }
         else
         {
            map[1] = ChannelNameMono;
         }
         map[2] = ChannelNameEOL;
      }

      // Let the client know the sample rate
      SetSampleRate(left->GetRate());

      // Get the block size the client wants to use
      auto max = left->GetMaxBlockSize() * 2;
      mBlockSize = SetBlockSize(max);

      // Calculate the buffer size to be at least the max rounded up to the clients
      // selected block size.
      const auto prevBufferSize = mBufferSize;
      mBufferSize = ((max + (mBlockSize - 1)) / mBlockSize) * mBlockSize;

      // If the buffer size has changed, then (re)allocate the buffers
      if (prevBufferSize != mBufferSize)
      {
         // Always create the number of input buffers the client expects even if we don't have
         // the same number of channels.
         inBufPos.reinit( mNumAudioIn );
         inBuffer.reinit( mNumAudioIn, mBufferSize );

         // We won't be using more than the first 2 buffers, so clear the rest (if any)
         for (size_t i = 2; i < mNumAudioIn; i++)
         {
            for (size_t j = 0; j < mBufferSize; j++)
            {
               inBuffer[i][j] = 0.0;
            }
         }

         // Always create the number of output buffers the client expects even if we don't have
         // the same number of channels.
         // Output buffers get an extra mBlockSize worth to give extra room if
         // the plugin adds latency
         outBufPos.reinit( mNumAudioOut );
         outBuffer.reinit( mNumAudioOut, mBufferSize + mBlockSize );
      }

      // (Re)Set the input buffer positions
      for (size_t i = 0; i < mNumAudioIn; i++)
      {
         inBufPos[i] = inBuffer[i].get();
      }

      // (Re)Set the output buffer positions
      for (size_t i = 0; i < mNumAudioOut; i++)
      {
         outBufPos[i] = outBuffer[i].get();
      }

      // Clear unused input buffers
      if (!right && !clear && mNumAudioIn > 1)
      {
         for (size_t j = 0; j < mBufferSize; j++)
         {
            inBuffer[1][j] = 0.0;
         }
         clear = true;
      }

      // Go process the track(s)
      bGoodResult = ProcessTrack(
         count, map, left, right, leftStart, rightStart, len,
         inBuffer, outBuffer, inBufPos, outBufPos);
      if (!bGoodResult)
      {
         break;
      }

      count++;
   }

   if (bGoodResult && GetType() == EffectTypeGenerate)
   {
      mT1 = mT0 + mDuration;
   }

   return bGoodResult;
}

bool Effect::ProcessTrack(int count,
                          ChannelNames map,
                          WaveTrack *left,
                          WaveTrack *right,
                          sampleCount leftStart,
                          sampleCount rightStart,
                          sampleCount len,
                          FloatBuffers &inBuffer,
                          FloatBuffers &outBuffer,
                          ArrayOf< float * > &inBufPos,
                          ArrayOf< float *> &outBufPos)
{
   bool rc = true;

   // Give the plugin a chance to initialize
   if (!ProcessInitialize(len, map))
   {
      return false;
   }

   { // Start scope for cleanup
   auto cleanup = finally( [&] {
      // Allow the plugin to cleanup
      if (!ProcessFinalize())
      {
         // In case of non-exceptional flow of control, set rc
         rc = false;
      }
   } );

   // For each input block of samples, we pass it to the effect along with a
   // variable output location.  This output location is simply a pointer into a
   // much larger buffer.  This reduces the number of calls required to add the
   // samples to the output track.
   //
   // Upon return from the effect, the output samples are "moved to the left" by
   // the number of samples in the current latency setting, effectively removing any
   // delay introduced by the effect.
   //
   // At the same time the total number of delayed samples are gathered and when
   // there is no further input data to process, the loop continues to call the
   // effect with an empty input buffer until the effect has had a chance to 
   // return all of the remaining delayed samples.
   auto inLeftPos = leftStart;
   auto inRightPos = rightStart;
   auto outLeftPos = leftStart;
   auto outRightPos = rightStart;

   auto inputRemaining = len;
   decltype(GetLatency()) curDelay = 0, delayRemaining = 0;
   decltype(mBlockSize) curBlockSize = 0;

   decltype(mBufferSize) inputBufferCnt = 0;
   decltype(mBufferSize) outputBufferCnt = 0;
   bool cleared = false;

   auto chans = std::min<unsigned>(mNumAudioOut, mNumChannels);

   std::unique_ptr<WaveTrack> genLeft, genRight;
   decltype(len) genLength = 0;
   bool isGenerator = GetType() == EffectTypeGenerate;
   bool isProcessor = GetType() == EffectTypeProcess;
   double genDur = 0;
   if (isGenerator)
   {
      if (mIsPreview) {
         gPrefs->Read(wxT("/AudioIO/EffectsPreviewLen"), &genDur, 6.0);
         genDur = wxMin(mDuration, CalcPreviewInputLength(genDur));
      }
      else {
         genDur = mDuration;
      }

      genLength = sampleCount((left->GetRate() * genDur) + 0.5);  // round to nearest sample
      delayRemaining = genLength;
      cleared = true;

      // Create temporary tracks
      genLeft = mFactory->NewWaveTrack(left->GetSampleFormat(), left->GetRate());
      if (right)
      {
         genRight = mFactory->NewWaveTrack(right->GetSampleFormat(), right->GetRate());
      }
   }

   // Call the effect until we run out of input or delayed samples
   while (inputRemaining != 0 || delayRemaining != 0)
   {
      // Still working on the input samples
      if (inputRemaining != 0)
      {
         // Need to refill the input buffers
         if (inputBufferCnt == 0)
         {
            // Calculate the number of samples to get
            inputBufferCnt =
               limitSampleBufferSize( mBufferSize, inputRemaining );

            // Fill the input buffers
            left->Get((samplePtr) inBuffer[0].get(), floatSample, inLeftPos, inputBufferCnt);
            if (right)
            {
               right->Get((samplePtr) inBuffer[1].get(), floatSample, inRightPos, inputBufferCnt);
            }

            // Reset the input buffer positions
            for (size_t i = 0; i < mNumChannels; i++)
            {
               inBufPos[i] = inBuffer[i].get();
            }
         }

         // Calculate the number of samples to process
         curBlockSize = mBlockSize;
         if (curBlockSize > inputRemaining)
         {
            // We've reached the last block...set current block size to what's left 
            // inputRemaining is positive and bounded by a size_t
            curBlockSize = inputRemaining.as_size_t();
            inputRemaining = 0;

            // Clear the remainder of the buffers so that a full block can be passed
            // to the effect
            auto cnt = mBlockSize - curBlockSize;
            for (size_t i = 0; i < mNumChannels; i++)
            {
               for (decltype(cnt) j = 0 ; j < cnt; j++)
               {
                  inBufPos[i][j + curBlockSize] = 0.0;
               }
            }

            // Might be able to use up some of the delayed samples
            if (delayRemaining != 0)
            {
               // Don't use more than needed
               cnt = limitSampleBufferSize(cnt, delayRemaining);
               delayRemaining -= cnt;
               curBlockSize += cnt;
            }
         }
      }
      // We've exhausted the input samples and are now working on the delay
      else if (delayRemaining != 0)
      {
         // Calculate the number of samples to process
         curBlockSize = limitSampleBufferSize( mBlockSize, delayRemaining );
         delayRemaining -= curBlockSize;

         // From this point on, we only want to feed zeros to the plugin
         if (!cleared)
         {
            // Reset the input buffer positions
            for (size_t i = 0; i < mNumChannels; i++)
            {
               inBufPos[i] = inBuffer[i].get();

               // And clear
               for (size_t j = 0; j < mBlockSize; j++)
               {
                  inBuffer[i][j] = 0.0;
               }
            }
            cleared = true;
         }
      }

      // Finally call the plugin to process the block
      decltype(curBlockSize) processed;
      try
      {
         processed = ProcessBlock(inBufPos.get(), outBufPos.get(), curBlockSize);
      }
      catch( const AudacityException &e )
      {
         // PRL: Bug 437:
         // Pass this along to our application-level handler
         throw;
      }
      catch(...)
      {
         // PRL:
         // Exceptions for other reasons, maybe in third-party code...
         // Continue treating them as we used to, but I wonder if these
         // should now be treated the same way.
         return false;
      }
      wxASSERT(processed == curBlockSize);
      wxUnusedVar(processed);

      // Bump to next input buffer position
      if (inputRemaining != 0)
      {
         for (size_t i = 0; i < mNumChannels; i++)
         {
            inBufPos[i] += curBlockSize;
         }
         inputRemaining -= curBlockSize;
         inputBufferCnt -= curBlockSize;
      }

      // "ls" and "rs" serve as the input sample index for the left and
      // right channels when processing the input samples.  If we flip
      // over to processing delayed samples, they simply become counters
      // for the progress display.
      inLeftPos += curBlockSize;
      inRightPos += curBlockSize;

      // Get the current number of delayed samples and accumulate
      if (isProcessor)
      {
         auto delay = GetLatency();
         curDelay += delay;
         delayRemaining += delay;

         // If the plugin has delayed the output by more samples than our current
         // block size, then we leave the output pointers alone.  This effectively
         // removes those delayed samples from the output buffer.
         if (curDelay >= curBlockSize)
         {
            curDelay -= curBlockSize;
            curBlockSize = 0;
         }
         // We have some delayed samples, at the beginning of the output samples,
         // so overlay them by shifting the remaining output samples.
         else if (curDelay > 0)
         {
            // curDelay is bounded by curBlockSize:
            auto delay = curDelay.as_size_t();
            curBlockSize -= delay;
            for (size_t i = 0; i < chans; i++)
            {
               memmove(outBufPos[i], outBufPos[i] + delay, sizeof(float) * curBlockSize);
            }
            curDelay = 0;
         }
      }

      // Adjust the number of samples in the output buffers
      outputBufferCnt += curBlockSize;

      // Still have room in the output buffers
      if (outputBufferCnt < mBufferSize)
      {
         // Bump to next output buffer position
         for (size_t i = 0; i < chans; i++)
         {
            outBufPos[i] += curBlockSize;
         }
      }
      // Output buffers have filled
      else
      {
         if (isProcessor)
         {
            // Write them out
            left->Set((samplePtr) outBuffer[0].get(), floatSample, outLeftPos, outputBufferCnt);
            if (right)
            {
               if (chans >= 2)
               {
                  right->Set((samplePtr) outBuffer[1].get(), floatSample, outRightPos, outputBufferCnt);
               }
               else
               {
                  right->Set((samplePtr) outBuffer[0].get(), floatSample, outRightPos, outputBufferCnt);
               }
            }
         }
         else if (isGenerator)
         {
            genLeft->Append((samplePtr) outBuffer[0].get(), floatSample, outputBufferCnt);
            if (genRight)
            {
               genRight->Append((samplePtr) outBuffer[1].get(), floatSample, outputBufferCnt);
            }
         }

         // Reset the output buffer positions
         for (size_t i = 0; i < chans; i++)
         {
            outBufPos[i] = outBuffer[i].get();
         }

         // Bump to the next track position
         outLeftPos += outputBufferCnt;
         outRightPos += outputBufferCnt;
         outputBufferCnt = 0;
      }

      if (mNumChannels > 1)
      {
         if (TrackGroupProgress(count,
               (inLeftPos - leftStart).as_double() /
               (isGenerator ? genLength : len).as_double()))
         {
            rc = false;
            break;
         }
      }
      else
      {
         if (TrackProgress(count,
               (inLeftPos - leftStart).as_double() /
               (isGenerator ? genLength : len).as_double()))
         {
            rc = false;
            break;
         }
      }
   }

   // Put any remaining output
   if (rc && outputBufferCnt)
   {
      if (isProcessor)
      {
         left->Set((samplePtr) outBuffer[0].get(), floatSample, outLeftPos, outputBufferCnt);
         if (right)
         {
            if (chans >= 2)
            {
               right->Set((samplePtr) outBuffer[1].get(), floatSample, outRightPos, outputBufferCnt);
            }
            else
            {
               right->Set((samplePtr) outBuffer[0].get(), floatSample, outRightPos, outputBufferCnt);
            }
         }
      }
      else if (isGenerator)
      {
         genLeft->Append((samplePtr) outBuffer[0].get(), floatSample, outputBufferCnt);
         if (genRight)
         {
            genRight->Append((samplePtr) outBuffer[1].get(), floatSample, outputBufferCnt);
         }
      }
   }

   if (rc && isGenerator)
   {
      AudacityProject *p = GetActiveProject();

      // PRL:  this code was here and could not have been the right
      // intent, mixing time and sampleCount values:
      // StepTimeWarper warper(mT0 + genLength, genLength - (mT1 - mT0));

      // This looks like what it should have been:
      // StepTimeWarper warper(mT0 + genDur, genDur - (mT1 - mT0));
      // But rather than fix it, I will just disable the use of it for now.
      // The purpose was to remap split lines inside the selected region when
      // a generator replaces it with sound of different duration.  But
      // the "correct" version might have the effect of mapping some splits too
      // far left, to before the selection.
      // In practice the wrong version probably did nothing most of the time,
      // because the cutoff time for the step time warper was 44100 times too
      // far from mT0.

      // Transfer the data from the temporary tracks to the actual ones
      genLeft->Flush();
      // mT1 gives us the NEW selection. We want to replace up to GetSel1().
      left->ClearAndPaste(mT0, p->GetSel1(), genLeft.get(), true, true,
                          nullptr /* &warper */);

      if (genRight)
      {
         genRight->Flush();
         right->ClearAndPaste(mT0, mT1, genRight.get(), true, true,
                              nullptr /* &warper */);
      }
   }

   } // End scope for cleanup
   return rc;
}

void Effect::End()
{
}

void Effect::PopulateOrExchange(ShuttleGui & WXUNUSED(S))
{
   return;
}

bool Effect::TransferDataToWindow()
{
   return true;
}

bool Effect::TransferDataFromWindow()
{
   return true;
}

bool Effect::EnableApply(bool enable)
{
   // May be called during initialization, so try to find the dialog
   wxWindow *dlg = mUIDialog;
   if (!dlg && mUIParent)
   {
      dlg = wxGetTopLevelParent(mUIParent);
   }

   if (dlg)
   {
      wxWindow *apply = dlg->FindWindow(wxID_APPLY);

      // Don't allow focus to get trapped
      if (!enable)
      {
         wxWindow *focus = dlg->FindFocus();
         if (focus == apply)
         {
            dlg->FindWindow(wxID_CLOSE)->SetFocus();
         }
      }

      apply->Enable(enable);
   }

   EnablePreview(enable);

   return enable;
}

bool Effect::EnablePreview(bool enable)
{
   // May be called during initialization, so try to find the dialog
   wxWindow *dlg = mUIDialog;
   if (!dlg && mUIParent)
   {
      dlg = wxGetTopLevelParent(mUIParent);
   }

   if (dlg)
   {
      wxWindow *play = dlg->FindWindow(kPlayID);
      if (play)
      {
         wxWindow *rewind = dlg->FindWindow(kRewindID);
         wxWindow *ffwd = dlg->FindWindow(kFFwdID);

         // Don't allow focus to get trapped
         if (!enable)
         {
            wxWindow *focus = dlg->FindFocus();
            if (focus && (focus == play || focus == rewind || focus == ffwd))
            {
               dlg->FindWindow(wxID_CLOSE)->SetFocus();
            }
         }

         play->Enable(enable);
         if (SupportsRealtime())
         {
            rewind->Enable(enable);
            ffwd->Enable(enable);
         }
      }
   }

   return enable;
}

void Effect::EnableDebug(bool enable)
{
   mUIDebug = enable;
}

void Effect::SetLinearEffectFlag(bool linearEffectFlag)
{
   mIsLinearEffect = linearEffectFlag;
}

void Effect::SetPreviewFullSelectionFlag(bool previewDurationFlag)
{
   mPreviewFullSelection = previewDurationFlag;
}


void Effect::IncludeNotSelectedPreviewTracks(bool includeNotSelected)
{
   mPreviewWithNotSelected = includeNotSelected;
}

bool Effect::TotalProgress(double frac)
{
   auto updateResult = (mProgress ?
      mProgress->Update(frac) :
      ProgressResult::Success);
   return (updateResult != ProgressResult::Success);
}

bool Effect::TrackProgress(int whichTrack, double frac, const wxString &msg)
{
   auto updateResult = (mProgress ?
      mProgress->Update(whichTrack + frac, (double) mNumTracks, msg) :
      ProgressResult::Success);
   return (updateResult != ProgressResult::Success);
}

bool Effect::TrackGroupProgress(int whichGroup, double frac, const wxString &msg)
{
   auto updateResult = (mProgress ?
      mProgress->Update(whichGroup + frac, (double) mNumGroups, msg) :
      ProgressResult::Success);
   return (updateResult != ProgressResult::Success);
}

void Effect::GetSamples(
   const WaveTrack *track, sampleCount *start, sampleCount *len)
{
   double trackStart = track->GetStartTime();
   double trackEnd = track->GetEndTime();
   double t0 = mT0 < trackStart ? trackStart : mT0;
   double t1 = mT1 > trackEnd ? trackEnd : mT1;

#if 0
   if (GetType() & INSERT_EFFECT) {
      t1 = t0 + mDuration;
      if (mT0 == mT1) {
         // Not really part of the calculation, but convenient to put here
         track->InsertSilence(t0, t1);
      }
   }
#endif

   if (t1 > t0) {
      *start = track->TimeToLongSamples(t0);
      auto end = track->TimeToLongSamples(t1);
      *len = end - *start;
   }
   else {
      *start = 0;
      *len  = 0;
   }
}

//
// private methods
//
// Use these two methods to copy the input tracks to mOutputTracks, if
// doing the processing on them, and replacing the originals only on success (and not cancel).
// Copy the group tracks that have tracks selected
void Effect::CopyInputTracks()
{
   CopyInputTracks(Track::Wave);
}

void Effect::CopyInputTracks(int trackType)
{
   // Reset map
   mIMap.clear();
   mOMap.clear();

   mOutputTracks = std::make_unique<TrackList>();
   mOutputTracksType = trackType;

   //iterate over tracks of type trackType (All types if Track::All)
   TrackListOfKindIterator aIt(trackType, mTracks);
   t2bHash added;

   for (Track *aTrack = aIt.First(); aTrack; aTrack = aIt.Next())
   {
      // Include selected tracks, plus sync-lock selected tracks for Track::All.
      if (aTrack->GetSelected() ||
            (trackType == Track::All && aTrack->IsSyncLockSelected()))
      {
         Track *o = mOutputTracks->Add(aTrack->Duplicate());
         mIMap.push_back(aTrack);
         mOMap.push_back(o);
      }
   }
}

Track *Effect::AddToOutputTracks(std::unique_ptr<Track> &&t)
{
   mIMap.push_back(NULL);
   mOMap.push_back(t.get());
   return mOutputTracks->Add(std::move(t));
}

Effect::AddedAnalysisTrack::AddedAnalysisTrack(Effect *pEffect, const wxString &name)
   : mpEffect(pEffect)
{
   LabelTrack::Holder pTrack{ pEffect->mFactory->NewLabelTrack() };
   mpTrack = pTrack.get();
   if (!name.empty())
      pTrack->SetName(name);
   pEffect->mTracks->Add(std::move(pTrack));
}

Effect::AddedAnalysisTrack::AddedAnalysisTrack(AddedAnalysisTrack &&that)
{
   mpEffect = that.mpEffect;
   mpTrack = that.mpTrack;
   that.Commit();
}

void Effect::AddedAnalysisTrack::Commit()
{
   mpEffect = nullptr;
}

Effect::AddedAnalysisTrack::~AddedAnalysisTrack()
{
   if (mpEffect) {
      // not committed -- DELETE the label track
      mpEffect->mTracks->Remove(mpTrack);
   }
}

auto Effect::AddAnalysisTrack(const wxString &name) -> std::shared_ptr<AddedAnalysisTrack>
{
   return std::shared_ptr<AddedAnalysisTrack>
      { safenew AddedAnalysisTrack{ this, name } };
}

Effect::ModifiedAnalysisTrack::ModifiedAnalysisTrack
   (Effect *pEffect, const LabelTrack *pOrigTrack, const wxString &name)
   : mpEffect(pEffect)
{
   // copy LabelTrack here, so it can be undone on cancel
   auto newTrack = pOrigTrack->Copy(pOrigTrack->GetStartTime(), pOrigTrack->GetEndTime());

   mpTrack = static_cast<LabelTrack*>(newTrack.get());

   // Why doesn't LabelTrack::Copy complete the job? :
   mpTrack->SetOffset(pOrigTrack->GetStartTime());
   if (!name.empty())
      mpTrack->SetName(name);

   // mpOrigTrack came from mTracks which we own but expose as const to subclasses
   // So it's okay that we cast it back to const
   mpOrigTrack =
      pEffect->mTracks->Replace(const_cast<LabelTrack*>(pOrigTrack),
#ifdef __AUDACITY_OLD_STD__
      std::shared_ptr<Track>(newTrack.release())
#else
      std::move(newTrack)
#endif
   );
}

Effect::ModifiedAnalysisTrack::ModifiedAnalysisTrack(ModifiedAnalysisTrack &&that)
{
   mpEffect = that.mpEffect;
   mpTrack = that.mpTrack;
   mpOrigTrack = std::move(that.mpOrigTrack);
   that.Commit();
}

void Effect::ModifiedAnalysisTrack::Commit()
{
   mpEffect = nullptr;
}

Effect::ModifiedAnalysisTrack::~ModifiedAnalysisTrack()
{
   if (mpEffect) {
      // not committed -- DELETE the label track
      // mpOrigTrack came from mTracks which we own but expose as const to subclasses
      // So it's okay that we cast it back to const
      mpEffect->mTracks->Replace(mpTrack, std::move(mpOrigTrack));
   }
}

auto Effect::ModifyAnalysisTrack
   (const LabelTrack *pOrigTrack, const wxString &name) -> ModifiedAnalysisTrack
{
   return{ this, pOrigTrack, name };
}

// If bGoodResult, replace mTracks tracks with successfully processed mOutputTracks copies.
// Else clear and DELETE mOutputTracks copies.
void Effect::ReplaceProcessedTracks(const bool bGoodResult)
{
   if (!bGoodResult) {
      // Free resources, unless already freed.

      // Processing failed or was cancelled so throw away the processed tracks.
      if ( mOutputTracks )
         mOutputTracks->Clear();

      // Reset map
      mIMap.clear();
      mOMap.clear();

      mOutputTracksType = Track::None;

      //TODO:undo the non-gui ODTask transfer
      return;
   }

   // Assume resources need to be freed.
   wxASSERT(mOutputTracks); // Make sure we at least did the CopyInputTracks().

   auto iterOut = mOutputTracks->begin(), iterEnd = mOutputTracks->end();

   size_t cnt = mOMap.size();
   size_t i = 0;

   for (; iterOut != iterEnd; ++i) {
      ListOfTracks::value_type o = std::move(*iterOut);
      // If tracks were removed from mOutputTracks, then there will be
      // tracks in the map that must be removed from mTracks.
      while (i < cnt && mOMap[i] != o.get()) {
         const auto t = mIMap[i];
         if (t) {
            mTracks->Remove(t);
         }
         i++;
      }

      // This should never happen
      wxASSERT(i < cnt);

      // Remove the track from the output list...don't DELETE it
      iterOut = mOutputTracks->erase(iterOut);

      const auto  t = mIMap[i];
      if (t == NULL)
      {
         // This track is a NEW addition to output tracks; add it to mTracks
         mTracks->Add(std::move(o));
      }
      else
      {
         // Replace mTracks entry with the NEW track
         WaveTrack *newTrack = static_cast<WaveTrack*>(o.get());
         mTracks->Replace(t, std::move(o));

         // Swap the wavecache track the ondemand task uses, since now the NEW
         // one will be kept in the project
         if (ODManager::IsInstanceCreated()) {
            ODManager::Instance()->ReplaceWaveTrack((WaveTrack *)t,
                                                    newTrack);
         }
      }
   }

   // If tracks were removed from mOutputTracks, then there may be tracks
   // left at the end of the map that must be removed from mTracks.
   while (i < cnt) {
      const auto t = mIMap[i];
      if (t) {
         mTracks->Remove(t);
      }
      i++;
   }

   // Reset map
   mIMap.clear();
   mOMap.clear();

   // Make sure we processed everything
   wxASSERT(mOutputTracks->empty());

   // The output list is no longer needed
   mOutputTracks.reset();
   mOutputTracksType = Track::None;
}

void Effect::CountWaveTracks()
{
   mNumTracks = 0;
   mNumGroups = 0;

   TrackListOfKindIterator iter(Track::Wave, mTracks);
   Track *t = iter.First();

   while(t) {
      if (!t->GetSelected()) {
         t = iter.Next();
         continue;
      }

      if (t->GetKind() == Track::Wave) {
         mNumTracks++;
         if (!t->GetLinked())
            mNumGroups++;
      }
      t = iter.Next();
   }
}

double Effect::CalcPreviewInputLength(double previewLength)
{
   return previewLength;
}

// RealtimeAddProcessor and RealtimeProcess use the same method of
// determining the current processor index, so updates to one should
// be reflected in the other.
bool Effect::RealtimeAddProcessor(int group, unsigned chans, float rate)
{
   auto ichans = chans;
   auto ochans = chans;
   auto gchans = chans;

   // Reset processor index
   if (group == 0)
   {
      mCurrentProcessor = 0;
      mGroupProcessor.Clear();
   }

   // Remember the processor starting index
   mGroupProcessor.Add(mCurrentProcessor);

   // Call the client until we run out of input or output channels
   while (ichans > 0 && ochans > 0)
   {
      // If we don't have enough input channels to accomodate the client's
      // requirements, then we replicate the input channels until the
      // client's needs are met.
      if (ichans < mNumAudioIn)
      {
         // All input channels have been consumed
         ichans = 0;
      }
      // Otherwise fullfil the client's needs with as many input channels as possible.
      // After calling the client with this set, we will loop back up to process more
      // of the input/output channels.
      else if (ichans >= mNumAudioIn)
      {
         gchans = mNumAudioIn;
         ichans -= gchans;
      }

      // If we don't have enough output channels to accomodate the client's
      // requirements, then we provide all of the output channels and fulfill
      // the client's needs with dummy buffers.  These will just get tossed.
      if (ochans < mNumAudioOut)
      {
         // All output channels have been consumed
         ochans = 0;
      }
      // Otherwise fullfil the client's needs with as many output channels as possible.
      // After calling the client with this set, we will loop back up to process more
      // of the input/output channels.
      else if (ochans >= mNumAudioOut)
      {
         ochans -= mNumAudioOut;
      }

      // Add a NEW processor
      RealtimeAddProcessor(gchans, rate);

      // Bump to next processor
      mCurrentProcessor++;
   }

   return true;
}

// RealtimeAddProcessor and RealtimeProcess use the same method of
// determining the current processor group, so updates to one should
// be reflected in the other.
size_t Effect::RealtimeProcess(int group,
                                    unsigned chans,
                                    float **inbuf,
                                    float **outbuf,
                                    size_t numSamples)
{
   //
   // The caller passes the number of channels to process and specifies
   // the number of input and output buffers.  There will always be the
   // same number of output buffers as there are input buffers.
   //
   // Effects always require a certain number of input and output buffers,
   // so if the number of channels we're curently processing are different
   // than what the effect expects, then we use a few methods of satisfying
   // the effects requirements.
   float **clientIn = (float **) alloca(mNumAudioIn * sizeof(float *));
   float **clientOut = (float **) alloca(mNumAudioOut * sizeof(float *));
   float *dummybuf = (float *) alloca(numSamples * sizeof(float));
   decltype(numSamples) len = 0;
   auto ichans = chans;
   auto ochans = chans;
   auto gchans = chans;
   unsigned indx = 0;
   unsigned ondx = 0;

   int processor = mGroupProcessor[group];

   // Call the client until we run out of input or output channels
   while (ichans > 0 && ochans > 0)
   {
      // If we don't have enough input channels to accomodate the client's
      // requirements, then we replicate the input channels until the
      // client's needs are met.
      if (ichans < mNumAudioIn)
      {
         for (size_t i = 0; i < mNumAudioIn; i++)
         {
            if (indx == ichans)
            {
               indx = 0;
            }
            clientIn[i] = inbuf[indx++];
         }

         // All input channels have been consumed
         ichans = 0;
      }
      // Otherwise fullfil the client's needs with as many input channels as possible.
      // After calling the client with this set, we will loop back up to process more
      // of the input/output channels.
      else if (ichans >= mNumAudioIn)
      {
         gchans = 0;
         for (size_t i = 0; i < mNumAudioIn; i++, ichans--, gchans++)
         {
            clientIn[i] = inbuf[indx++];
         }
      }

      // If we don't have enough output channels to accomodate the client's
      // requirements, then we provide all of the output channels and fulfill
      // the client's needs with dummy buffers.  These will just get tossed.
      if (ochans < mNumAudioOut)
      {
         for (size_t i = 0; i < mNumAudioOut; i++)
         {
            if (i < ochans)
            {
               clientOut[i] = outbuf[i];
            }
            else
            {
               clientOut[i] = dummybuf;
            }
         }

         // All output channels have been consumed
         ochans = 0;
      }
      // Otherwise fullfil the client's needs with as many output channels as possible.
      // After calling the client with this set, we will loop back up to process more
      // of the input/output channels.
      else if (ochans >= mNumAudioOut)
      {
         for (size_t i = 0; i < mNumAudioOut; i++, ochans--)
         {
            clientOut[i] = outbuf[ondx++];
         }
      }

      // Finally call the plugin to process the block
      len = 0;
      for (decltype(numSamples) block = 0; block < numSamples; block += mBlockSize)
      {
         auto cnt = std::min(numSamples - block, mBlockSize);
         len += RealtimeProcess(processor, clientIn, clientOut, cnt);

         for (size_t i = 0 ; i < mNumAudioIn; i++)
         {
            clientIn[i] += cnt;
         }

         for (size_t i = 0 ; i < mNumAudioOut; i++)
         {
            clientOut[i] += cnt;
         }
      }

      // Bump to next processor
      processor++;
   }

   return len;
}

bool Effect::IsRealtimeActive()
{
   return mRealtimeSuspendCount == 0;
}

bool Effect::IsHidden()
{
   return false;
}

void Effect::Preview(bool dryOnly)
{
   if (mNumTracks == 0) { // nothing to preview
      return;
   }

   if (gAudioIO->IsBusy()) {
      return;
   }

   wxWindow *FocusDialog = wxWindow::FindFocus();

   double previewDuration;
   bool isNyquist = (GetFamily().IsSameAs(NYQUISTEFFECTS_FAMILY))? true : false;
   bool isGenerator = GetType() == EffectTypeGenerate;

   // Mix a few seconds of audio from all of the tracks
   double previewLen;
   gPrefs->Read(wxT("/AudioIO/EffectsPreviewLen"), &previewLen, 6.0);

   const double rate = mProjectRate;

   if (isNyquist && isGenerator) {
      previewDuration = CalcPreviewInputLength(previewLen);
   }
   else {
      previewDuration = wxMin(mDuration, CalcPreviewInputLength(previewLen));
   }

   double t1 = mT0 + previewDuration;

   if ((t1 > mT1) && !(isNyquist && isGenerator)) {
      t1 = mT1;
   }

   if (t1 <= mT0)
      return;

   bool success = true;
   auto vr0 = valueRestorer( mT0 );
   auto vr1 = valueRestorer( mT1 );
   // Most effects should stop at t1.
   if (!mPreviewFullSelection)
      mT1 = t1;

   // Save the original track list
   TrackList *saveTracks = mTracks;

   auto cleanup = finally( [&] {
      mTracks = saveTracks;

      // Effect is already inited; we will call Process, End, and then Init
      // again, so the state is exactly the way it was before Preview
      // was called.
      if (!dryOnly) {
         End();
         GuardedCall< void >( [&]{ Init(); } );
      }

      if (FocusDialog) {
         FocusDialog->SetFocus();
      }

      // In case of failed effect, be sure to free memory.
      ReplaceProcessedTracks( false );
   } );

   // Build NEW tracklist from rendering tracks
   auto uTracks = std::make_unique<TrackList>();
   mTracks = uTracks.get();

   // Linear Effect preview optimised by pre-mixing to one track.
   // Generators need to generate per track.
   if (mIsLinearEffect && !isGenerator) {
      WaveTrack::Holder mixLeft, mixRight;
      MixAndRender(saveTracks, mFactory, rate, floatSample, mT0, t1, mixLeft, mixRight);
      if (!mixLeft)
         return;

      mixLeft->Offset(-mixLeft->GetStartTime());
      mixLeft->InsertSilence(0.0, mT0);
      mixLeft->SetSelected(true);
      mixLeft->SetDisplay(WaveTrack::NoDisplay);
      mTracks->Add(std::move(mixLeft));
      if (mixRight) {
         mixRight->Offset(-mixRight->GetStartTime());
         mixRight->InsertSilence(0.0, mT0);
         mixRight->SetSelected(true);
         mTracks->Add(std::move(mixRight));
      }
   }
   else {
      TrackListOfKindIterator iter(Track::Wave, saveTracks);
      WaveTrack *src = (WaveTrack *) iter.First();
      while (src)
      {
         if (src->GetSelected() || mPreviewWithNotSelected) {
            auto dest = src->Copy(mT0, t1);
            dest->InsertSilence(0.0, mT0);
            dest->SetSelected(src->GetSelected());
            static_cast<WaveTrack*>(dest.get())->SetDisplay(WaveTrack::NoDisplay);
            mTracks->Add(std::move(dest));
         }
         src = (WaveTrack *) iter.Next();
      }
   }


   // Update track/group counts
   CountWaveTracks();

   // Apply effect
   if (!dryOnly) {
      ProgressDialog progress{
         GetName(),
         _("Preparing preview"),
         pdlgHideCancelButton
      }; // Have only "Stop" button.
      auto vr = valueRestorer( mProgress, &progress );

      auto vr2 = valueRestorer( mIsPreview, true );

      success = Process();
   }

   if (success)
   {
      WaveTrackConstArray playbackTracks;
      WaveTrackArray recordingTracks;

      SelectedTrackListOfKindIterator iter(Track::Wave, mTracks);
      WaveTrack *src = (WaveTrack *) iter.First();
      while (src) {
         playbackTracks.push_back(src);
         src = (WaveTrack *) iter.Next();
      }
      // Some effects (Paulstretch) may need to generate more
      // than previewLen, so take the min.
      t1 = std::min(mT0 + previewLen, mT1);

#ifdef EXPERIMENTAL_MIDI_OUT
      NoteTrackArray empty;
#endif
      // Start audio playing
      AudioIOStartStreamOptions options { rate };
      int token =
         gAudioIO->StartStream(playbackTracks, recordingTracks,
#ifdef EXPERIMENTAL_MIDI_OUT
                            empty,
#endif
                            mT0, t1, options);

      if (token) {
         auto previewing = ProgressResult::Success;
         // The progress dialog must be deleted before stopping the stream
         // to allow events to flow to the app during StopStream processing.
         // The progress dialog blocks these events.
         {
            ProgressDialog progress
            (GetName(), _("Previewing"), pdlgHideCancelButton);

            while (gAudioIO->IsStreamActive(token) && previewing == ProgressResult::Success) {
               ::wxMilliSleep(100);
               previewing = progress.Update(gAudioIO->GetStreamTime() - mT0, t1 - mT0);
            }
         }

         gAudioIO->StopStream();

         while (gAudioIO->IsBusy()) {
            ::wxMilliSleep(100);
         }
      }
      else {
         wxMessageBox(_("Error opening sound device. Try changing the audio host, playback device and the project sample rate."),
                      _("Error"), wxOK | wxICON_EXCLAMATION, FocusDialog);
      }
   }
}

BEGIN_EVENT_TABLE(EffectDialog, wxDialogWrapper)
   EVT_BUTTON(wxID_OK, EffectDialog::OnOk)
END_EVENT_TABLE()

EffectDialog::EffectDialog(wxWindow * parent,
                           const wxString & title,
                           int type,
                           int flags,
                           int additionalButtons)
: wxDialogWrapper(parent, wxID_ANY, title, wxDefaultPosition, wxDefaultSize, flags)
{
   mType = type;
   mAdditionalButtons = additionalButtons;
}

void EffectDialog::Init()
{
   ShuttleGui S(this, eIsCreating);

   S.SetBorder(5);
   S.StartVerticalLay(true);
   {
      PopulateOrExchange(S);

      long buttons = eOkButton;
      if (mType != EffectTypeAnalyze)
      {
         buttons |= eCancelButton;
         if (mType == EffectTypeProcess)
         {
            buttons |= ePreviewButton;
         }
      }
      S.AddStandardButtons(buttons|mAdditionalButtons);
   }
   S.EndVerticalLay();

   Layout();
   Fit();
   SetMinSize(GetSize());
   Center();
}

/// This is a virtual function which will be overridden to
/// provide the actual parameters that we want for each
/// kind of dialog.
void EffectDialog::PopulateOrExchange(ShuttleGui & WXUNUSED(S))
{
   return;
}

bool EffectDialog::TransferDataToWindow()
{
   ShuttleGui S(this, eIsSettingToDialog);
   PopulateOrExchange(S);

   return true;
}

bool EffectDialog::TransferDataFromWindow()
{
   ShuttleGui S(this, eIsGettingFromDialog);
   PopulateOrExchange(S);

   return true;
}

bool EffectDialog::Validate()
{
   return true;
}

void EffectDialog::OnPreview(wxCommandEvent & WXUNUSED(evt))
{
   return;
}

void EffectDialog::OnOk(wxCommandEvent & WXUNUSED(evt))
{
   // On wxGTK (wx2.8.12), the default action is still executed even if
   // the button is disabled.  This appears to affect all wxDialogs, not
   // just our Effects dialogs.  So, this is a only temporary workaround
   // for legacy effects that disable the OK button.  Hopefully this has
   // been corrected in wx3.
   if (FindWindow(wxID_OK)->IsEnabled() && Validate() && TransferDataFromWindow())
   {
      EndModal(true);
   }

   return;
}

///////////////////////////////////////////////////////////////////////////////
//
// EffectPanel
//
///////////////////////////////////////////////////////////////////////////////

class EffectPanel final : public wxPanelWrapper
{
public:
   EffectPanel(wxWindow *parent)
   :  wxPanelWrapper(parent)
   {
      // This fools NVDA into not saying "Panel" when the dialog gets focus
      SetName(wxT("\a"));
      SetLabel(wxT("\a"));

      mAcceptsFocus = true;
   }

   virtual ~EffectPanel()
   {
   }

   // ============================================================================
   // wxWindow implementation
   // ============================================================================

   bool AcceptsFocus() const override
   {
      return mAcceptsFocus;
   }

   // So that wxPanel is not included in Tab traversal, when required - see wxWidgets bug 15581
   bool AcceptsFocusFromKeyboard() const override
   {
      return mAcceptsFocus;
   }

   // ============================================================================
   // EffectPanel implementation
   // ============================================================================
   void SetAccept(bool accept)
   {
      mAcceptsFocus = accept;
   }

private:
   bool mAcceptsFocus;
};

///////////////////////////////////////////////////////////////////////////////
//
// EffectUIHost
//
///////////////////////////////////////////////////////////////////////////////

#include "../../images/Effect.h"

BEGIN_EVENT_TABLE(EffectUIHost, wxDialogWrapper)
   EVT_INIT_DIALOG(EffectUIHost::OnInitDialog)
   EVT_ERASE_BACKGROUND(EffectUIHost::OnErase)
   EVT_PAINT(EffectUIHost::OnPaint)
   EVT_CLOSE(EffectUIHost::OnClose)
   EVT_BUTTON(wxID_APPLY, EffectUIHost::OnApply)
   EVT_BUTTON(wxID_CANCEL, EffectUIHost::OnCancel)
   EVT_BUTTON(eDebugID, EffectUIHost::OnDebug)
   EVT_BUTTON(kMenuID, EffectUIHost::OnMenu)
   EVT_CHECKBOX(kEnableID, EffectUIHost::OnEnable)
   EVT_BUTTON(kPlayID, EffectUIHost::OnPlay)
   EVT_BUTTON(kRewindID, EffectUIHost::OnRewind)
   EVT_BUTTON(kFFwdID, EffectUIHost::OnFFwd)
   EVT_MENU(kSaveAsID, EffectUIHost::OnSaveAs)
   EVT_MENU(kImportID, EffectUIHost::OnImport)
   EVT_MENU(kExportID, EffectUIHost::OnExport)
   EVT_MENU(kOptionsID, EffectUIHost::OnOptions)
   EVT_MENU(kDefaultsID, EffectUIHost::OnDefaults)
   EVT_MENU_RANGE(kUserPresetsID, kUserPresetsID + 999, EffectUIHost::OnUserPreset)
   EVT_MENU_RANGE(kDeletePresetID, kDeletePresetID + 999, EffectUIHost::OnDeletePreset)
   EVT_MENU_RANGE(kFactoryPresetsID, kFactoryPresetsID + 999, EffectUIHost::OnFactoryPreset)
END_EVENT_TABLE()

EffectUIHost::EffectUIHost(wxWindow *parent,
                           Effect *effect,
                           EffectUIClientInterface *client)
:  wxDialogWrapper(parent, wxID_ANY, effect->GetName(),
            wxDefaultPosition, wxDefaultSize,
            wxDEFAULT_DIALOG_STYLE | wxRESIZE_BORDER | wxMINIMIZE_BOX | wxMAXIMIZE_BOX)
{
#if defined(__WXMAC__)
   // Make sure the effect window actually floats above the main window
   [[((NSView *)GetHandle()) window] setLevel:NSFloatingWindowLevel];
#endif

   SetName(effect->GetName());
   SetExtraStyle(wxWS_EX_VALIDATE_RECURSIVELY);

   mParent = parent;
   mEffect = effect;
   mClient = client;

   mProject = GetActiveProject();

   mInitialized = false;
   mSupportsRealtime = false;

   mDisableTransport = false;

   mEnabled = true;

   mPlayPos = 0.0;

   mClient->SetHostUI(this);
}

EffectUIHost::~EffectUIHost()
{
   CleanupRealtime();

   if (mClient)
   {
      mClient->CloseUI();
      mClient = NULL;
   }
}

// ============================================================================
// wxWindow implementation
// ============================================================================

bool EffectUIHost::TransferDataToWindow()
{
   return mEffect->TransferDataToWindow();
}

bool EffectUIHost::TransferDataFromWindow()
{
   return mEffect->TransferDataFromWindow();
}

// ============================================================================
// wxDialog implementation
// ============================================================================

int EffectUIHost::ShowModal()
{
#if defined(__WXMSW__)
   // Swap the Close and Apply buttons
   wxSizer *sz = mApplyBtn->GetContainingSizer();
   wxASSERT(mApplyBtn->GetParent()); // To justify safenew
   wxButton *apply = safenew wxButton(mApplyBtn->GetParent(), wxID_APPLY);
   sz->Replace(mCloseBtn, apply);
   sz->Replace(mApplyBtn, mCloseBtn);
   sz->Layout();
   mApplyBtn->Destroy();
   mApplyBtn = apply;
   mApplyBtn->SetDefault();
   mApplyBtn->SetLabel(wxGetStockLabel(wxID_OK, 0));
   mCloseBtn->SetLabel(wxGetStockLabel(wxID_CANCEL, 0));
#else
   mApplyBtn->SetLabel(wxGetStockLabel(wxID_OK));
   mCloseBtn->SetLabel(wxGetStockLabel(wxID_CANCEL));
#endif

   Layout();

   return wxDialogWrapper::ShowModal();
}

// ============================================================================
// EffectUIHost implementation
// ============================================================================

bool EffectUIHost::Initialize()
{
   EffectPanel *w = safenew EffectPanel(this);
   {
      auto vs = std::make_unique<wxBoxSizer>(wxVERTICAL);
      {
         auto hs = std::make_unique<wxBoxSizer>(wxHORIZONTAL);

         // Try to give the window a sensible default/minimum size
         w->SetMinSize(wxSize(wxMax(600, mParent->GetSize().GetWidth() * 2 / 3),
            mParent->GetSize().GetHeight() / 2));

         mDisableTransport = !gAudioIO->IsAvailable(mProject);
         mPlaying = gAudioIO->IsStreamActive(); // not exactly right, but will suffice
         mCapturing = gAudioIO->IsStreamActive() && gAudioIO->GetNumCaptureChannels() > 0;

         if (!mClient->PopulateUI(w))
         {
            return false;
         }

         hs->Add(w, 1, wxEXPAND);
         vs->Add(hs.release(), 1, wxEXPAND);
      }

      wxPanel *buttonPanel = safenew wxPanelWrapper(this, wxID_ANY);
      wxPanel *const bar = safenew wxPanelWrapper(buttonPanel, wxID_ANY);

      // This fools NVDA into not saying "Panel" when the dialog gets focus
      bar->SetName(wxT("\a"));
      bar->SetLabel(wxT("\a"));

      {
         auto bs = std::make_unique<wxBoxSizer>(wxHORIZONTAL);

         mSupportsRealtime = mEffect->SupportsRealtime();
         mIsGUI = mClient->IsGraphicalUI();
         mIsBatch = mEffect->IsBatchProcessing();

         wxBitmapButton *bb;

         int margin = 0;

#if defined(__WXMAC__)
         margin = 3; // I'm sure it's needed because of the order things are created...
#endif   

         if (!mIsGUI)
         {
            wxASSERT(bar); // To justify safenew
            mMenuBtn = safenew wxButton(bar, kMenuID, _("&Manage"));
            bs->Add(mMenuBtn, 0, wxALIGN_CENTER | wxTOP | wxBOTTOM, margin);
         }
         else
         {
            wxASSERT(bar); // To justify safenew
            mMenuBtn = safenew wxBitmapButton(bar, kMenuID, CreateBitmap(effect_menu_xpm, true, false));
#if defined(__WXMAC__)
            mMenuBtn->SetName(_("&Manage"));
#else
            mMenuBtn->SetLabel(_("&Manage"));
#endif
            bs->Add(mMenuBtn);
         }
         mMenuBtn->SetToolTip(_("Manage presets and options"));

         bs->Add(5, 5);

         if (!mIsBatch)
         {
            if (!mIsGUI)
            {
               if (mSupportsRealtime)
               {
                  wxASSERT(bar); // To justify safenew
                  mPlayToggleBtn = safenew wxButton(bar, kPlayID, _("Start &Playback"));
                  mPlayToggleBtn->SetToolTip(_("Start and stop playback"));
                  bs->Add(mPlayToggleBtn, 0, wxALIGN_CENTER | wxTOP | wxBOTTOM, margin);
               }
               else if (mEffect->GetType() != EffectTypeAnalyze)
               {
                  wxASSERT(bar); // To justify safenew
                  mPlayToggleBtn = safenew wxButton(bar, kPlayID, _("&Preview"));
                  mPlayToggleBtn->SetToolTip(_("Preview effect"));
                  bs->Add(mPlayToggleBtn, 0, wxALIGN_CENTER | wxTOP | wxBOTTOM, margin);
               }
            }
            else
            {
               mPlayBM = CreateBitmap(effect_play_xpm, true, false);
               mPlayDisabledBM = CreateBitmap(effect_play_disabled_xpm, true, false);
               mStopBM = CreateBitmap(effect_stop_xpm, true, false);
               mStopDisabledBM = CreateBitmap(effect_stop_disabled_xpm, true, false);
               wxASSERT(bar); // To justify safenew
               bb = safenew wxBitmapButton(bar, kPlayID, mPlayBM);
               bb->SetBitmapDisabled(mPlayDisabledBM);
               mPlayBtn = bb;
               bs->Add(mPlayBtn);
               if (!mSupportsRealtime)
               {
                  mPlayBtn->SetToolTip(_("Preview effect"));
#if defined(__WXMAC__)
                  mPlayBtn->SetName(_("Preview effect"));
#else
                  mPlayBtn->SetLabel(_("&Preview effect"));
#endif
               }
            }

            if (mSupportsRealtime)
            {
               if (!mIsGUI)
               {
                  wxASSERT(bar); // To justify safenew
                  mRewindBtn = safenew wxButton(bar, kRewindID, _("Skip &Backward"));
                  bs->Add(mRewindBtn, 0, wxALIGN_CENTER | wxTOP | wxBOTTOM, margin);
               }
               else
               {
                  wxASSERT(bar); // To justify safenew
                  bb = safenew wxBitmapButton(bar, kRewindID, CreateBitmap(effect_rewind_xpm, true, true));
                  bb->SetBitmapDisabled(CreateBitmap(effect_rewind_disabled_xpm, true, true));
                  mRewindBtn = bb;
#if defined(__WXMAC__)
                  mRewindBtn->SetName(_("Skip &Backward"));
#else
                  mRewindBtn->SetLabel(_("Skip &Backward"));
#endif
                  bs->Add(mRewindBtn);
               }
               mRewindBtn->SetToolTip(_("Skip backward"));

               if (!mIsGUI)
               {
                  wxASSERT(bar); // To justify safenew
                  mFFwdBtn = safenew wxButton(bar, kFFwdID, _("Skip &Forward"));
                  bs->Add(mFFwdBtn, 0, wxALIGN_CENTER | wxTOP | wxBOTTOM, margin);
               }
               else
               {
                  wxASSERT(bar); // To justify safenew
                  bb = safenew wxBitmapButton(bar, kFFwdID, CreateBitmap(effect_ffwd_xpm, true, true));
                  bb->SetBitmapDisabled(CreateBitmap(effect_ffwd_disabled_xpm, true, true));
                  mFFwdBtn = bb;
#if defined(__WXMAC__)
                  mFFwdBtn->SetName(_("Skip &Foreward"));
#else
                  mFFwdBtn->SetLabel(_("Skip &Foreward"));
#endif
                  bs->Add(mFFwdBtn);
               }
               mFFwdBtn->SetToolTip(_("Skip forward"));

               bs->Add(5, 5);

               mEnableCb = safenew wxCheckBox(bar, kEnableID, _("&Enable"));
               mEnableCb->SetValue(mEnabled);
               mEnableCb->SetName(_("Enable"));
               bs->Add(mEnableCb, 0, wxALIGN_CENTER | wxTOP | wxBOTTOM, margin);
            }
         }

         bar->SetSizerAndFit(bs.release());
      }

      // TODO: Add Help button
      // long buttons = eApplyButton + eCloseButton + eHelpButton;
      long buttons = eApplyButton + eCloseButton;
      if (mEffect->mUIDebug)
      {
         buttons += eDebugButton;
      }

      buttonPanel->SetSizer(CreateStdButtonSizer(buttonPanel, buttons, bar).release());
      vs->Add(buttonPanel, 0, wxEXPAND);

      SetSizer(vs.release());
   }

   Layout();
   Fit();
   Center();

   mApplyBtn = (wxButton *) FindWindow(wxID_APPLY);
   mCloseBtn = (wxButton *) FindWindow(wxID_CANCEL);

   UpdateControls();

   w->SetAccept(!mIsGUI);
   (!mIsGUI ? w : FindWindow(wxID_APPLY))->SetFocus();
 
   LoadUserPresets();

   InitializeRealtime();

   SetMinSize(GetSize());
   return true;
}

void EffectUIHost::OnInitDialog(wxInitDialogEvent & evt)
{
   // Do default handling
   wxDialogWrapper::OnInitDialog(evt);

#if wxCHECK_VERSION(3, 0, 0)
//#warning "check to see if this still needed in wx3"
#endif

   // Pure hackage coming down the pike...
   //
   // I have no idea why, but if a wxTextCtrl is the first control in the
   // panel, then its contents will not be automatically selected when the
   // dialog is displayed.
   //
   // So, we do the selection manually.
   wxTextCtrl *focused = wxDynamicCast(FindFocus(), wxTextCtrl);
   if (focused)
   {
      focused->SelectAll();
   }
}

void EffectUIHost::OnErase(wxEraseEvent & WXUNUSED(evt))
{
   // Ignore it
}

void EffectUIHost::OnPaint(wxPaintEvent & WXUNUSED(evt))
{
   wxPaintDC dc(this);

   dc.Clear();
}

void EffectUIHost::OnClose(wxCloseEvent & WXUNUSED(evt))
{
   DoCancel();

   CleanupRealtime();

   Hide();

   mClient->CloseUI();
   mClient = NULL;

   Destroy();
}

void EffectUIHost::OnApply(wxCommandEvent & evt)
{
   // On wxGTK (wx2.8.12), the default action is still executed even if
   // the button is disabled.  This appears to affect all wxDialogs, not
   // just our Effects dialogs.  So, this is a only temporary workaround
   // for legacy effects that disable the OK button.  Hopefully this has
   // been corrected in wx3.
   if (!FindWindow(wxID_APPLY)->IsEnabled())
   {
      return;
   }

   // Honor the "select all if none" preference...a little hackish, but whatcha gonna do...
   if (!mIsBatch && mEffect->GetType() != EffectTypeGenerate && mProject->mViewInfo.selectedRegion.isPoint())
   {
      auto flags = AlwaysEnabledFlag;
      bool allowed = mProject->TryToMakeActionAllowed(flags,
                                                      WaveTracksSelectedFlag | TimeSelectedFlag,
                                                      WaveTracksSelectedFlag | TimeSelectedFlag);
      if (!allowed)
      {
         wxMessageBox(_("You must select audio in the project window."));
         return;
      }
   }

   if (!mClient->ValidateUI())
   {
      return;
   }

   // This will take care of calling TransferDataFromWindow()
   if (!mEffect->SaveUserPreset(mEffect->GetCurrentSettingsGroup()))
   {
      return;
   }

   mEffect->mUIResultID = evt.GetId();

   if (IsModal())
   {
      mDismissed = true;

      EndModal(true);

      Close();

      return;
   }

   // Progress dialog no longer yields, so this "shouldn't" be necessary (yet to be proven
   // for sure), but it is a nice visual cue that something is going on.
   mApplyBtn->Disable();
   auto cleanup = finally( [&] { mApplyBtn->Enable(); } );

   mEffect->Apply();

   return;
}

void EffectUIHost::DoCancel()
{
   if (!mDismissed) {
      mEffect->mUIResultID = wxID_CANCEL;

      if (IsModal())
         EndModal(false);
      else
         Hide();

      mDismissed = true;
   }
}

void EffectUIHost::OnCancel(wxCommandEvent & evt)
{
   DoCancel();

   Close();

   return;
}

void EffectUIHost::OnDebug(wxCommandEvent & evt)
{
   OnApply(evt);

   mEffect->mUIResultID = evt.GetId();

   return;
}

void EffectUIHost::OnMenu(wxCommandEvent & WXUNUSED(evt))
{
   wxMenu menu;

   LoadUserPresets();

   if (mUserPresets.GetCount() == 0)
   {
      menu.Append(kUserPresetsDummyID, _("User Presets"))->Enable(false);
   }
   else
   {
      auto sub = std::make_unique<wxMenu>();
      for (size_t i = 0, cnt = mUserPresets.GetCount(); i < cnt; i++)
      {
         sub->Append(kUserPresetsID + i, mUserPresets[i]);
      }
      menu.Append(0, _("User Presets"), sub.release());
   }

   menu.Append(kSaveAsID, _("Save Preset..."));

   if (mUserPresets.GetCount() == 0)
   {
      menu.Append(kDeletePresetDummyID, _("Delete Preset"))->Enable(false);
   }
   else
   {
      auto sub = std::make_unique<wxMenu>();
      for (size_t i = 0, cnt = mUserPresets.GetCount(); i < cnt; i++)
      {
         sub->Append(kDeletePresetID + i, mUserPresets[i]);
      }
      menu.Append(0, _("Delete Preset"), sub.release());
   }

   menu.AppendSeparator();

   wxArrayString factory = mEffect->GetFactoryPresets();

   {
      auto sub = std::make_unique<wxMenu>();
      sub->Append(kDefaultsID, _("Defaults"));
      if (factory.GetCount() > 0)
      {
         sub->AppendSeparator();
         for (size_t i = 0, cnt = factory.GetCount(); i < cnt; i++)
         {
            wxString label = factory[i];
            if (label.IsEmpty())
            {
               label = _("None");
            }

            sub->Append(kFactoryPresetsID + i, label);
         }
      }
      menu.Append(0, _("Factory Presets"), sub.release());
   }

   menu.AppendSeparator();
   menu.Append(kImportID, _("Import..."))->Enable(mClient->CanExportPresets());
   menu.Append(kExportID, _("Export..."))->Enable(mClient->CanExportPresets());
   menu.AppendSeparator();
   menu.Append(kOptionsID, _("Options..."))->Enable(mClient->HasOptions());
   menu.AppendSeparator();

   {
      auto sub = std::make_unique<wxMenu>();

      sub->Append(kDummyID, wxString::Format(_("Type: %s"), mEffect->GetFamily().c_str()));
      sub->Append(kDummyID, wxString::Format(_("Name: %s"), mEffect->GetName().c_str()));
      sub->Append(kDummyID, wxString::Format(_("Version: %s"), mEffect->GetVersion().c_str()));
      sub->Append(kDummyID, wxString::Format(_("Vendor: %s"), mEffect->GetVendor().c_str()));
      sub->Append(kDummyID, wxString::Format(_("Description: %s"), mEffect->GetDescription().c_str()));

      menu.Append(0, _("About"), sub.release());
   }

   wxWindow *btn = FindWindow(kMenuID);
   wxRect r = btn->GetRect();
   btn->PopupMenu(&menu, r.GetLeft(), r.GetBottom());
}

void EffectUIHost::OnEnable(wxCommandEvent & WXUNUSED(evt))
{
   mEnabled = mEnableCb->GetValue();

   if (mEnabled)
   {
      if (!mClient->ValidateUI()) {
         // If we're previewing we should still be able to stop playback
         // so don't disable transport buttons.
         //   mEffect->EnableApply(false);   // currently this would also disable transport buttons.
         // The preferred behaviour is currently undecided, so for now
         // just disallow enabling until settings are valid.
         mEnabled = false;
         mEnableCb->SetValue(mEnabled);
         return;
      }
      mEffect->RealtimeResume();
   }
   else
   {
      mEffect->RealtimeSuspend();
   }

   UpdateControls();
}

void EffectUIHost::OnPlay(wxCommandEvent & WXUNUSED(evt))
{
   if (!mSupportsRealtime)
   {
      if (!mClient->ValidateUI() || !mEffect->TransferDataFromWindow())
      {
         return;
      }

      mEffect->Preview(false);

      return;
   }

   if (mPlaying)
   {
      mPlayPos = gAudioIO->GetStreamTime();
      mProject->GetControlToolBar()->StopPlaying();
   }
   else
   {
      if (mProject->IsPlayRegionLocked())
      {
         double t0, t1;
         mProject->GetPlayRegion(&t0, &t1);
         mRegion.setTimes(t0, t1);
         mPlayPos = mRegion.t0();
      }
      else if (mProject->mViewInfo.selectedRegion.t0() != mRegion.t0() ||
               mProject->mViewInfo.selectedRegion.t1() != mRegion.t1())
      {
         mRegion = mProject->mViewInfo.selectedRegion;
         mPlayPos = mRegion.t0();
      }

      if (mPlayPos > mRegion.t1())
      {
         mPlayPos = mRegion.t1();
      }

      mProject->GetControlToolBar()->PlayPlayRegion
         (SelectedRegion(mPlayPos, mRegion.t1()),
          mProject->GetDefaultPlayOptions(), PlayMode::normalPlay);
   }
}

void EffectUIHost::OnRewind(wxCommandEvent & WXUNUSED(evt))
{
   if (mPlaying)
   {
      double seek;
      gPrefs->Read(wxT("/AudioIO/SeekShortPeriod"), &seek, 1.0);

      double pos = gAudioIO->GetStreamTime();
      if (pos - seek < mRegion.t0())
      {
         seek = pos - mRegion.t0();
      }

      gAudioIO->SeekStream(-seek);
   }
   else
   {
      mPlayPos = mRegion.t0();
   }
}

void EffectUIHost::OnFFwd(wxCommandEvent & WXUNUSED(evt))
{
   if (mPlaying)
   {
      double seek;
      gPrefs->Read(wxT("/AudioIO/SeekShortPeriod"), &seek, 1.0);

      double pos = gAudioIO->GetStreamTime();
      if (mRegion.t0() < mRegion.t1() && pos + seek > mRegion.t1())
      {
         seek = mRegion.t1() - pos;
      }

      gAudioIO->SeekStream(seek);
   }
   else
   {
      // It allows to play past end of selection...probably useless
      mPlayPos = mRegion.t1();
   }
}

void EffectUIHost::OnPlayback(wxCommandEvent & evt)
{
   evt.Skip();

   if (evt.GetInt() != 0)
   {
      if (evt.GetEventObject() != mProject)
      {
         mDisableTransport = true;
      }
      else
      {
         mPlaying = true;
      }
   }
   else
   {
      mDisableTransport = false;
      mPlaying = false;
   }

   if (mPlaying)
   {
      mRegion = mProject->mViewInfo.selectedRegion;
      mPlayPos = mRegion.t0();
   }

   UpdateControls();
}

void EffectUIHost::OnCapture(wxCommandEvent & evt)
{
   evt.Skip();

   if (evt.GetInt() != 0)
   {
      if (evt.GetEventObject() != mProject)
      {
         mDisableTransport = true;
      }
      else
      {
         mCapturing = true;
      }
   }
   else
   {
      mDisableTransport = false;
      mCapturing = false;
   }

   UpdateControls();
}

void EffectUIHost::OnUserPreset(wxCommandEvent & evt)
{
   int preset = evt.GetId() - kUserPresetsID;

   mEffect->LoadUserPreset(mEffect->GetUserPresetsGroup(mUserPresets[preset]));

   return;
}

void EffectUIHost::OnFactoryPreset(wxCommandEvent & evt)
{
   mEffect->LoadFactoryPreset(evt.GetId() - kFactoryPresetsID);

   return;
}

void EffectUIHost::OnDeletePreset(wxCommandEvent & evt)
{
   wxString preset = mUserPresets[evt.GetId() - kDeletePresetID];

   int res = wxMessageBox(wxString::Format(_("Are you sure you want to delete \"%s\"?"), preset.c_str()),
                          _("Delete Preset"),
                          wxICON_QUESTION | wxYES_NO);
   if (res == wxYES)
   {
      mEffect->RemovePrivateConfigSubgroup(mEffect->GetUserPresetsGroup(preset));
   }

   LoadUserPresets();

   return;
}

void EffectUIHost::OnSaveAs(wxCommandEvent & WXUNUSED(evt))
{
   wxTextCtrl *text;
   wxString name;
   wxDialogWrapper dlg(this, wxID_ANY, wxString(_("Save Preset")));

   ShuttleGui S(&dlg, eIsCreating);

   S.StartPanel();
   {
      S.StartVerticalLay(1);
      {
         S.StartHorizontalLay(wxALIGN_LEFT, 0);
         {
            text = S.AddTextBox(_("Preset name:"), name, 30);
         }
         S.EndHorizontalLay();
         S.SetBorder(10);
         S.AddStandardButtons();
      }
      S.EndVerticalLay();
   }
   S.EndPanel();

   dlg.SetSize(dlg.GetSizer()->GetMinSize());
   dlg.Center();

   while (true)
   {
      int rc = dlg.ShowModal();

      if (rc != wxID_OK)
      {
         break;
      }

      name = text->GetValue();
      if (name.IsEmpty())
      {
         wxMessageDialog md(this,
                            _("You must specify a name"),
                            _("Save Preset"));
         md.Center();
         md.ShowModal();
         continue;
      }

      if (mUserPresets.Index(name) != wxNOT_FOUND)
      {
         wxMessageDialog md(this,
                            _("Preset already exists.\n\nReplace?"),
                            _("Save Preset"),
                            wxYES_NO | wxCANCEL | wxICON_EXCLAMATION);
         md.Center();
         int choice = md.ShowModal();
         if (choice == wxID_CANCEL)
         {
            break;
         }

         if (choice == wxID_NO)
         {
            continue;
         }
      }

      mEffect->SaveUserPreset(mEffect->GetUserPresetsGroup(name));
      LoadUserPresets();

      break;
   }

   return;
}

void EffectUIHost::OnImport(wxCommandEvent & WXUNUSED(evt))
{
   mClient->ImportPresets();

   LoadUserPresets();

   return;
}

void EffectUIHost::OnExport(wxCommandEvent & WXUNUSED(evt))
{
   // may throw
   // exceptions are handled in AudacityApp::OnExceptionInMainLoop
   mClient->ExportPresets();

   return;
}

void EffectUIHost::OnOptions(wxCommandEvent & WXUNUSED(evt))
{
   mClient->ShowOptions();

   return;
}

void EffectUIHost::OnDefaults(wxCommandEvent & WXUNUSED(evt))
{
   mEffect->LoadFactoryDefaults();

   return;
}

wxBitmap EffectUIHost::CreateBitmap(const char *xpm[], bool up, bool pusher)
{
   wxMemoryDC dc;
   wxBitmap pic(xpm);

   wxBitmap mod(pic.GetWidth() + 6, pic.GetHeight() + 6);
   dc.SelectObject(mod);

#if !defined(__WXMAC__)

#if defined(__WXGTK__)
   wxColour newColour = wxSystemSettings::GetColour(wxSYS_COLOUR_BACKGROUND);
#elif defined(__WXMSW__)
   wxColour newColour = wxSystemSettings::GetColour(wxSYS_COLOUR_BTNFACE);
#endif

   dc.SetBackground(wxBrush(newColour));
   dc.Clear();
#endif

   int offset = 3;
   if (pusher)
   {
      if (!up)
      {
         offset += 1;
      }
   }

   dc.DrawBitmap(pic, offset, offset, true);

   dc.SelectObject(wxNullBitmap);

   return mod;
}

void EffectUIHost::UpdateControls()
{
   if (mIsBatch)
   {
      return;
   }

   if (mCapturing || mDisableTransport)
   {
      // Don't allow focus to get trapped
      wxWindow *focus = FindFocus();
      if (focus == mRewindBtn || focus == mFFwdBtn || focus == mPlayBtn || focus == mEnableCb)
      {
         mCloseBtn->SetFocus();
      }
   }

   mApplyBtn->Enable(!mCapturing);
   if (mEffect->GetType() != EffectTypeAnalyze)
   {
      (!mIsGUI ? mPlayToggleBtn : mPlayBtn)->Enable(!(mCapturing || mDisableTransport));
   }

   if (mSupportsRealtime)
   {
      mRewindBtn->Enable(!(mCapturing || mDisableTransport));
      mFFwdBtn->Enable(!(mCapturing || mDisableTransport));
      mEnableCb->Enable(!(mCapturing || mDisableTransport));

      wxBitmapButton *bb;

      if (mPlaying)
      {
         if (!mIsGUI)
         {
            /* i18n-hint: The access key "&P" should be the same in
               "Stop &Playback" and "Start &Playback" */
            mPlayToggleBtn->SetLabel(_("Stop &Playback"));
            mPlayToggleBtn->Refresh();
         }
         else
         {
            bb = (wxBitmapButton *) mPlayBtn;
            bb->SetBitmapLabel(mStopBM);
            bb->SetBitmapDisabled(mStopDisabledBM);
            bb->SetToolTip(_("Stop"));
#if defined(__WXMAC__)
            bb->SetName(_("Stop &Playback"));
#else
            bb->SetLabel(_("Stop &Playback"));
#endif
         }
      }
      else
      {
         if (!mIsGUI)
         {
            /* i18n-hint: The access key "&P" should be the same in
               "Stop &Playback" and "Start &Playback" */
            mPlayToggleBtn->SetLabel(_("Start &Playback"));
            mPlayToggleBtn->Refresh();
         }
         else
         {
            bb = (wxBitmapButton *) mPlayBtn;
            bb->SetBitmapLabel(mPlayBM);
            bb->SetBitmapDisabled(mPlayDisabledBM);
            bb->SetToolTip(_("Play"));
#if defined(__WXMAC__)
            bb->SetName(_("Start &Playback"));
#else
            bb->SetLabel(_("Start &Playback"));
#endif
         }
      }
   }
}

void EffectUIHost::LoadUserPresets()
{
   mUserPresets.Clear();

   mEffect->GetPrivateConfigSubgroups(mEffect->GetUserPresetsGroup(wxEmptyString), mUserPresets);

   mUserPresets.Sort();

   return;
}

void EffectUIHost::InitializeRealtime()
{
   if (mSupportsRealtime && !mInitialized)
   {
      EffectManager::Get().RealtimeAddEffect(mEffect);

      wxTheApp->Connect(EVT_AUDIOIO_PLAYBACK,
                        wxCommandEventHandler(EffectUIHost::OnPlayback),
                        NULL,
                        this);

      wxTheApp->Connect(EVT_AUDIOIO_CAPTURE,
                        wxCommandEventHandler(EffectUIHost::OnCapture),
                        NULL,
                        this);

      mInitialized = true;
   }
}

void EffectUIHost::CleanupRealtime()
{
   if (mSupportsRealtime && mInitialized)
   {
      wxTheApp->Disconnect(EVT_AUDIOIO_PLAYBACK,
                           wxCommandEventHandler(EffectUIHost::OnPlayback),
                           NULL,
                           this);

      wxTheApp->Disconnect(EVT_AUDIOIO_CAPTURE,
                           wxCommandEventHandler(EffectUIHost::OnCapture),
                           NULL,
                           this);

      EffectManager::Get().RealtimeRemoveEffect(mEffect);

      mInitialized = false;
   }
}

///////////////////////////////////////////////////////////////////////////////
//
// EffectPresetsDialog
//
///////////////////////////////////////////////////////////////////////////////

enum
{
   ID_Type = 10000
};

BEGIN_EVENT_TABLE(EffectPresetsDialog, wxDialogWrapper)
   EVT_CHOICE(ID_Type, EffectPresetsDialog::OnType)
   EVT_LISTBOX_DCLICK(wxID_ANY, EffectPresetsDialog::OnOk)
   EVT_BUTTON(wxID_OK, EffectPresetsDialog::OnOk)
   EVT_BUTTON(wxID_CANCEL, EffectPresetsDialog::OnCancel)
END_EVENT_TABLE()

EffectPresetsDialog::EffectPresetsDialog(wxWindow *parent, Effect *effect)
:  wxDialogWrapper(parent, wxID_ANY, wxString(_("Select Preset")))
{
   ShuttleGui S(this, eIsCreating);
   S.StartVerticalLay();
   {
      S.StartTwoColumn();
      S.SetStretchyCol(1);
      {
         wxArrayString empty;

         S.AddPrompt(_("Type:"));
         mType = S.Id(ID_Type).AddChoice(wxT(""), wxT(""), &empty);
         mType->SetSelection(0);

         S.AddPrompt(_("&Preset:"));
         mPresets = S.AddListBox(&empty, wxLB_SINGLE | wxLB_NEEDED_SB );
      }
      S.EndTwoColumn();

      S.AddStandardButtons();
   }
   S.EndVerticalLay();

   mUserPresets = effect->GetUserPresets();
   mFactoryPresets = effect->GetFactoryPresets();

   if (mUserPresets.GetCount() > 0)
   {
      mType->Append(_("User Presets"));
   }

   if (mFactoryPresets.GetCount() > 0)
   {
      mType->Append(_("Factory Presets"));
   }

   if (effect->HasCurrentSettings())
   {
      mType->Append(_("Current Settings"));
   }

   if (effect->HasFactoryDefaults())
   {
      mType->Append(_("Factory Defaults"));
   }

   UpdateUI();
}

EffectPresetsDialog::~EffectPresetsDialog()
{
}

wxString EffectPresetsDialog::GetSelected() const
{
   return mSelection;
}

void EffectPresetsDialog::SetSelected(const wxString & parms)
{
   wxString preset = parms;
   if (preset.StartsWith(Effect::kUserPresetIdent))
   {
      preset.Replace(Effect::kUserPresetIdent, wxEmptyString, false);
      SetPrefix(_("User Presets"), preset);
   }
   else if (preset.StartsWith(Effect::kFactoryPresetIdent))
   {
      preset.Replace(Effect::kFactoryPresetIdent, wxEmptyString, false);
      SetPrefix(_("Factory Presets"), preset);
   }
   else if (preset.StartsWith(Effect::kCurrentSettingsIdent))
   {
      SetPrefix(_("Current Settings"), wxEmptyString);
   }
   else if (preset.StartsWith(Effect::kFactoryDefaultsIdent))
   {
      SetPrefix(_("Factory Defaults"), wxEmptyString);
   }
}

void EffectPresetsDialog::SetPrefix(const wxString & type, const wxString & prefix)
{
   mType->SetStringSelection(type);

   if (type.IsSameAs(_("User Presets")))
   {
      mPresets->Clear();
      mPresets->Append(mUserPresets);
      mPresets->Enable(true);
      mPresets->SetStringSelection(prefix);
      if (mPresets->GetSelection() == wxNOT_FOUND)
      {
         mPresets->SetSelection(0);
      }
      mSelection = Effect::kUserPresetIdent + mPresets->GetStringSelection();
   }
   else if (type.IsSameAs(_("Factory Presets")))
   {
      mPresets->Clear();
      for (size_t i = 0, cnt = mFactoryPresets.GetCount(); i < cnt; i++)
      {
         wxString label = mFactoryPresets[i];
         if (label.IsEmpty())
         {
            label = _("None");
         }
         mPresets->Append(label);
      }
      mPresets->Enable(true);
      mPresets->SetStringSelection(prefix);
      if (mPresets->GetSelection() == wxNOT_FOUND)
      {
         mPresets->SetSelection(0);
      }
      mSelection = Effect::kFactoryPresetIdent + mPresets->GetStringSelection();
   }
   else if (type.IsSameAs(_("Current Settings")))
   {
      mPresets->Clear();
      mPresets->Enable(false);
      mSelection = Effect::kCurrentSettingsIdent;
   }
   else if (type.IsSameAs(_("Factory Defaults")))
   {
      mPresets->Clear();
      mPresets->Enable(false);
      mSelection = Effect::kFactoryDefaultsIdent;
   }
}

void EffectPresetsDialog::UpdateUI()
{
   int selected = mType->GetSelection();
   if (selected == wxNOT_FOUND)
   {
      selected = 0;
      mType->SetSelection(selected);
   }
   wxString type = mType->GetString(selected);

   if (type.IsSameAs(_("User Presets")))
   {
      selected = mPresets->GetSelection();
      if (selected == wxNOT_FOUND)
      {
         selected = 0;
      }

      mPresets->Clear();
      mPresets->Append(mUserPresets);
      mPresets->Enable(true);
      mPresets->SetSelection(selected);
      mSelection = Effect::kUserPresetIdent + mPresets->GetString(selected);
   }
   else if (type.IsSameAs(_("Factory Presets")))
   {
      selected = mPresets->GetSelection();
      if (selected == wxNOT_FOUND)
      {
         selected = 0;
      }

      mPresets->Clear();
      for (size_t i = 0, cnt = mFactoryPresets.GetCount(); i < cnt; i++)
      {
         wxString label = mFactoryPresets[i];
         if (label.IsEmpty())
         {
            label = _("None");
         }
         mPresets->Append(label);
      }
      mPresets->Enable(true);
      mPresets->SetSelection(selected);
      mSelection = Effect::kFactoryPresetIdent + mPresets->GetString(selected);
   }
   else if (type.IsSameAs(_("Current Settings")))
   {
      mPresets->Clear();
      mPresets->Enable(false);
      mSelection = Effect::kCurrentSettingsIdent;
   }
   else if (type.IsSameAs(_("Factory Defaults")))
   {
      mPresets->Clear();
      mPresets->Enable(false);
      mSelection = Effect::kFactoryDefaultsIdent;
   }
}

void EffectPresetsDialog::OnType(wxCommandEvent & WXUNUSED(evt))
{
   UpdateUI();
}

void EffectPresetsDialog::OnOk(wxCommandEvent & WXUNUSED(evt))
{
   UpdateUI();

   EndModal(true);
}

void EffectPresetsDialog::OnCancel(wxCommandEvent & WXUNUSED(evt))
{
   mSelection = wxEmptyString;

   EndModal(false);
}