Committing Paul's spectral nagivation commands patch

From:

http://audacity.238276.n2.nabble.com/Patch-spectral-peak-snapping-navigation-commands-td7565648.html

src/Menus.cpp

@@ -574,7 +574,11 @@ void AudacityProject::CreateMenusAndCommands()
    c->AddItem(wxT("SelectNone"), _("&None"), FN(OnSelectNone), wxT("Ctrl+Shift+A"));
 
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
+   c->BeginSubMenu(_("S&pectral"));
    c->AddItem(wxT("ToggleSpectralSelection"), _("To&ggle spectral selection"), FN(OnToggleSpectralSelection), wxT("Q"));
+   c->AddItem(wxT("NextHigherPeakFrequency"), _("Next Higher Peak Frequency"), FN(OnNextHigherPeakFrequency));
+   c->AddItem(wxT("NextLowerPeakFrequency"), _("Next Lower Peak Frequency"), FN(OnNextLowerPeakFrequency));
+   c->EndSubMenu();
 #endif
 
    c->AddItem(wxT("SetLeftSelection"), _("&Left at Playback Position"), FN(OnSetLeftSelection), wxT("["));
@@ -4728,6 +4732,39 @@ void AudacityProject::OnToggleSpectralSelection()
    mTrackPanel->Refresh(false);
    ModifyState(false);
 }
+
+void AudacityProject::DoNextPeakFrequency(bool up)
+{
+   // Find the first selected wave track that is in a spectrogram view.
+   WaveTrack *pTrack = 0;
+   SelectedTrackListOfKindIterator iter(Track::Wave, mTracks);
+   for (Track *t = iter.First(); t; t = iter.Next()) {
+      WaveTrack *const wt = static_cast<WaveTrack*>(t);
+      const int display = wt->GetDisplay();
+      if (display == WaveTrack::SpectrumDisplay ||
+          display == WaveTrack::SpectrumLogDisplay) {
+         pTrack = wt;
+         break;
+      }
+   }
+
+   if (pTrack) {
+      mTrackPanel->SnapCenterOnce(pTrack, up);
+      mTrackPanel->Refresh(false);
+      ModifyState(false);
+   }
+}
+
+void AudacityProject::OnNextHigherPeakFrequency()
+{
+   DoNextPeakFrequency(true);
+}
+
+
+void AudacityProject::OnNextLowerPeakFrequency()
+{
+   DoNextPeakFrequency(false);
+}
 #endif
 
 void AudacityProject::OnSelectCursorEnd()

src/Menus.h

@@ -245,6 +245,9 @@ void OnSelectAll();
 void OnSelectNone();
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
 void OnToggleSpectralSelection();
+void DoNextPeakFrequency(bool up);
+void OnNextHigherPeakFrequency();
+void OnNextLowerPeakFrequency();
 #endif
 void OnSelectCursorEnd();
 void OnSelectStartCursor();

src/TrackPanel.cpp

@@ -2644,6 +2644,45 @@ inline double findMaxRatio(double center, double rate)
 
 }
 
+void TrackPanel::SnapCenterOnce(WaveTrack *pTrack, bool up)
+{
+   const int windowSize = mTrackArtist->GetSpectrumWindowSize();
+   const double rate = pTrack->GetRate();
+   const double nyq = rate / 2.0;
+   const double binFrequency = rate / windowSize;
+
+   double f1 = mViewInfo->selectedRegion.f1();
+   double centerFrequency = mViewInfo->selectedRegion.fc();
+   if (centerFrequency <= 0) {
+      centerFrequency = up ? binFrequency : nyq;
+      f1 = centerFrequency * sqrt(2.0);
+   }
+
+   const double ratio = f1 / centerFrequency;
+   const int originalBin = floor(0.5 + centerFrequency / binFrequency);
+   const int limitingBin = up ? floor(0.5 + nyq / binFrequency) : 1;
+
+   // This is crude and wasteful, doing the FFT each time the command is called.
+   // It would be better to cache the data, but then invalidation of the cache would
+   // need doing in all places that change the time selection.
+   StartSnappingFreqSelection(pTrack);
+   double snappedFrequency = centerFrequency;
+   int bin = originalBin;
+   if (up) {
+      while (snappedFrequency <= centerFrequency &&
+             bin < limitingBin)
+         snappedFrequency = mFrequencySnapper->FindPeak(++bin * binFrequency, NULL);
+   }
+   else {
+      while (snappedFrequency >= centerFrequency &&
+         bin > limitingBin)
+         snappedFrequency = mFrequencySnapper->FindPeak(--bin * binFrequency, NULL);
+   }
+
+   mViewInfo->selectedRegion.setFrequencies
+      (snappedFrequency / ratio, snappedFrequency * ratio);
+}
+
 void TrackPanel::StartSnappingFreqSelection (WaveTrack *pTrack)
 {
    static const sampleCount minLength = 8;

src/TrackPanel.h

@@ -328,6 +328,9 @@ class AUDACITY_DLL_API TrackPanel:public wxPanel {
       double quietSeekStepPositive, double audioSeekStepPositive);
 
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
+public:
+   void SnapCenterOnce (WaveTrack *pTrack, bool up);
+protected:
    void StartSnappingFreqSelection (WaveTrack *pTrack);
    void MoveSnappingFreqSelection (int mouseYCoordinate,
                                    int trackTopEdge,