TempoChange.cpp

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/*  SPDX-License-Identifier: GPL-2.0-or-later */
/*!********************************************************************
 
  Audacity: A Digital Audio Editor
 
  TempoChange.cpp
 
  PaulLicameli
 
**********************************************************************/
#include "TempoChange.h"
#include "Channel.h"
 
namespace {
struct ProjectTempo : ClientData::Cloneable<> {
   ~ProjectTempo() = default;
   std::unique_ptr<ClientData::Cloneable<>> Clone() const override
   { return std::make_unique<ProjectTempo>(*this); }
 
   static ProjectTempo &Get(ChannelGroup &group);
   static const ProjectTempo &Get(const ChannelGroup &group);
 
   std::optional<double> mProjectTempo;
};
 
const ChannelGroup::Attachments::RegisteredFactory
projectTempoDataFactory{
   [](auto &) { return std::make_unique<ProjectTempo>(); } };
 
ProjectTempo &ProjectTempo::Get(ChannelGroup &group)
{
   return group.Attachments::Get<ProjectTempo>(projectTempoDataFactory);
}
 
const ProjectTempo &ProjectTempo::Get(const ChannelGroup &group)
{
   return Get(const_cast<ChannelGroup&>(group));
}
}
 
void DoProjectTempoChange(ChannelGroup &group, double newTempo)
{
   auto &oldTempo = ProjectTempo::Get(group).mProjectTempo;
   OnProjectTempoChange::Call(group, oldTempo, newTempo);
   oldTempo = newTempo;
}
 
const std::optional<double>& GetProjectTempo(const ChannelGroup &group)
{
   return ProjectTempo::Get(group).mProjectTempo;
}
 
DEFINE_ATTACHED_VIRTUAL(OnProjectTempoChange) {
   return [](auto&, auto&, auto){ };
}