Method UpdateTrackClusters

src/MixerBoard.cpp:970–1027

Reassign mixer input strips (MixerTrackClusters) to Track Clusters both have the same order. Note Tracks appear in the mixer, and we must be able to convert and reuse a MixerTrackCluster from audio to midi or midi to audio. This task is handled by UpdateForStateChange().

// UpdateForStateChange().
//
void MixerBoard::UpdateTrackClusters()
{
   if (!mImageMuteUp)
      this->CreateMuteSoloImages();

   const int nClusterHeight = mScrolledWindow->GetClientSize().GetHeight() - kDoubleInset;
   size_t nClusterCount = mMixerTrackClusters.size();
   unsigned int nClusterIndex = 0;
   MixerTrackCluster* pMixerTrackCluster = NULL;

   for (auto pPlayableTrack: mTracks->Any<PlayableTrack>()) {
      // TODO: more-than-two-channels
      auto spTrack = pPlayableTrack->SharedPointer<PlayableTrack>();
      // Track iterations always yield non-null pointers; maintain invariant
      // when reassigning
      assert(spTrack);
      if (nClusterIndex < nClusterCount)
      {
         // Already showing it.
         // Track clusters are maintained in the same order as the WaveTracks.
         // Track pointers can change for the "same" track for different states
         // on the undo stack, so update the pointers and display name.
         mMixerTrackClusters[nClusterIndex]->mTrack = spTrack;
         // Assume linked track is wave or null
         mMixerTrackClusters[nClusterIndex]->UpdateForStateChange();
      }
      else
      {
         // Not already showing it. Add a NEW MixerTrackCluster.
         wxPoint clusterPos(
            kInset + nClusterIndex * kMixerTrackClusterWidth,
            kInset);
         wxSize clusterSize(kMixerTrackClusterWidth, nClusterHeight);
         pMixerTrackCluster =
            safenew MixerTrackCluster(mScrolledWindow, this, mProject,
               *spTrack, clusterPos, clusterSize);
         if (pMixerTrackCluster)
            mMixerTrackClusters.push_back(pMixerTrackCluster);
      }
      nClusterIndex++;
   }

   if (pMixerTrackCluster)
   {
      // Added at least one MixerTrackCluster.
      this->UpdateWidth();
      this->ResizeTrackClusters();
   }
   else while (nClusterIndex < nClusterCount)
   {
      // We've got too many clusters.
      // This can happen only on things like Undo New Audio Track or Undo Import
      // that don't call RemoveTrackCluster explicitly.
      // We've already updated the track pointers for the clusters to the left, so just remove all the rest.
      // Successively DELETE from right to left.
      RemoveTrackCluster(--nClusterCount);
   }
}