ProjectTempoListener Class Reference

Inheritance diagram for ProjectTempoListener:

Collaboration diagram for ProjectTempoListener:

Public Member Functions
	ProjectTempoListener (AudacityProject &project, TrackList &trackList)
void	OnProjectTempoChange (double newTempo)
Public Member Functions inherited from ClientData::Base
virtual	~Base ()

Private Attributes
AudacityProject &	mProject
ViewInfo &	mViewInfo
double	mTempo { 0 }
TrackList &	mTrackList
Observer::Subscription	mTrackListSubstription
Observer::Subscription	mProjectTimeSignatureSubscription

Detailed Description

Definition at line 12 of file ProjectTempoListener.cpp.

Constructor & Destructor Documentation

ProjectTempoListener()

ProjectTempoListener::ProjectTempoListener	(	AudacityProject &	project,
		TrackList &	trackList
	)

Definition at line 34 of file ProjectTempoListener.cpp.

    : mProject { project }
    , mViewInfo { ViewInfo::Get(project) }
    , mTempo { ProjectTimeSignature::Get(project).GetTempo() }
    , mTrackList { trackList }
    , mTrackListSubstription { trackList.Subscribe(
         [this](const TrackListEvent& event) {
            if (event.mType == TrackListEvent::ADDITION)
            {
               const auto tempo = ProjectTimeSignature::Get(mProject).GetTempo();
               if (const auto track = event.mpTrack.lock())
                  DoProjectTempoChange(*track, tempo);
            }
         }) }
{
   mProjectTimeSignatureSubscription =
      ProjectTimeSignature::Get(project).Subscribe(
         [this](const TimeSignatureChangedMessage& event) {
            OnProjectTempoChange(event.newTempo);
         });
   assert(mTrackList.empty()); // No need to call `OnProjectTempoChange` yet ...
}

References TrackListEvent::ADDITION, DoProjectTempoChange(), ProjectTimeSignature::Get(), ProjectTimeSignature::GetTempo(), and mProject.

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Member Function Documentation

OnProjectTempoChange()

void ProjectTempoListener::OnProjectTempoChange

(

double

newTempo

)

Definition at line 58 of file ProjectTempoListener.cpp.

{
   for (auto track : mTrackList)
      DoProjectTempoChange(*track, newTempo);
   
   if(!mViewInfo.playRegion.Empty() && mTempo > 0 && newTempo > 0)
   {
      const auto tempoRate = mTempo / newTempo;
      mViewInfo.playRegion.SetTimes(
         mViewInfo.playRegion.GetStart() * tempoRate,
         mViewInfo.playRegion.GetEnd() * tempoRate
      );
   }
   mTempo = newTempo;
}

References DoProjectTempoChange(), PlayRegion::Empty(), PlayRegion::GetEnd(), PlayRegion::GetStart(), mTempo, mTrackList, mViewInfo, ViewInfo::playRegion, and PlayRegion::SetTimes().

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Member Data Documentation

mProject

AudacityProject& ProjectTempoListener::mProject

private

Definition at line 19 of file ProjectTempoListener.cpp.

Referenced by ProjectTempoListener().

mProjectTimeSignatureSubscription

Observer::Subscription ProjectTempoListener::mProjectTimeSignatureSubscription

private

Definition at line 24 of file ProjectTempoListener.cpp.

mTempo

double ProjectTempoListener::mTempo { 0 }

private

Definition at line 21 of file ProjectTempoListener.cpp.

Referenced by OnProjectTempoChange().

mTrackList

TrackList& ProjectTempoListener::mTrackList

private

Definition at line 22 of file ProjectTempoListener.cpp.

Referenced by OnProjectTempoChange().

mTrackListSubstription

Observer::Subscription ProjectTempoListener::mTrackListSubstription

private

Definition at line 23 of file ProjectTempoListener.cpp.

mViewInfo

ViewInfo& ProjectTempoListener::mViewInfo

private

Definition at line 20 of file ProjectTempoListener.cpp.

Referenced by OnProjectTempoChange().

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The documentation for this class was generated from the following file:

• ProjectTempoListener.cpp