Function FindAdjustedChannelHeights

src/TrackPanel.cpp:913–955

namespace {
std::vector<int> FindAdjustedChannelHeights(Track &t)
{
   auto channels = t.Channels();
   assert(!channels.empty());

   // Collect heights, and count affordances
   int nAffordances = 0;
   int totalHeight = 0;
   std::vector<int> oldHeights;
   for (auto pChannel : channels) {
      auto &view = ChannelView::Get(*pChannel);
      const auto height = view.GetHeight();
      totalHeight += height;
      oldHeights.push_back(height);
      if (view.GetAffordanceControls())
         ++nAffordances;
   }

   // Allocate results
   auto nChannels = static_cast<int>(oldHeights.size());
   std::vector<int> results;
   results.reserve(nChannels);

   // Now reallocate the channel heights for the presence of affordances
   // and separators
   auto availableHeight = totalHeight
      - nAffordances * kAffordancesAreaHeight
      - (nChannels - 1) * kChannelSeparatorThickness
      - kTrackSeparatorThickness;
   int cumulativeOldHeight = 0;
   int cumulativeNewHeight = 0;
   for (const auto &oldHeight : oldHeights) {
      // Preserve the porportions among the stored heights
      cumulativeOldHeight += oldHeight;
      const auto newHeight =
         cumulativeOldHeight * availableHeight / totalHeight
            - cumulativeNewHeight;
      cumulativeNewHeight += newHeight;
      results.push_back(newHeight);
   }

   return results;
}
}

void TrackPanel::UpdateVRulers()