Add support for zooming to show all notes, separate from max zoom

This is now the behavior of Zoom Reset, with Max Zoom being given the previous behavior.  Shift+Right-Click alternates between the two -- it zooms to all notes, unless it currently is zoomed to all notes in which case it performs a max zoom.

This fixes Bug 2093.  It also fixes Bug 1815, by performing the all-notes zoom when importing a track.

src/NoteTrack.cpp

@@ -1047,6 +1047,37 @@ void NoteTrack::ZoomTo(const wxRect &rect, int start, int end)
    SetNoteRange(pitch1, pitch2);
 }
 
+void NoteTrack::ZoomAllNotes()
+{
+   Alg_iterator iterator( &GetSeq(), false );
+   iterator.begin();
+   Alg_event_ptr evt;
+
+   // Go through all of the notes, finding the minimum and maximum value pitches.
+   bool hasNotes = false;
+   int minPitch = MaxPitch;
+   int maxPitch = MinPitch;
+
+   while (NULL != (evt = iterator.next())) {
+      if (evt->is_note()) {
+         int pitch = (int) evt->get_pitch();
+         hasNotes = true;
+         if (pitch < minPitch)
+            minPitch = pitch;
+         if (pitch > maxPitch)
+            maxPitch = pitch;
+      }
+   }
+
+   if (!hasNotes) {
+      // Semi-arbitary default values:
+      minPitch = 48;
+      maxPitch = 72;
+   }
+
+   SetNoteRange(minPitch, maxPitch);
+}
+
 NoteTrackDisplayData::NoteTrackDisplayData(const NoteTrack* track, const wxRect &r)
 {
    auto span = track->GetTopNote() - track->GetBottomNote() + 1; // + 1 to make sure it includes both

src/NoteTrack.h

@@ -131,6 +131,8 @@ class AUDACITY_DLL_API NoteTrack final
    /// Sets the top and bottom note (both pitches) automatically, swapping them if needed.
    void SetNoteRange(int note1, int note2);
 
+   /// Zooms so that all notes are visible
+   void ZoomAllNotes();
    /// Zooms so that the entire track is visible
    void ZoomMaxExtent() { SetNoteRange(MinPitch, MaxPitch); }
    /// Shifts all notes vertically by the given pitch

src/import/ImportMIDI.cpp

@@ -69,27 +69,8 @@ bool ImportMIDI(const FilePath &fName, NoteTrack * dest)
    wxString trackNameBase = fName.AfterLast(wxFILE_SEP_PATH).BeforeLast('.');
    dest->SetName(trackNameBase);
    mf.Close();
-   // the mean pitch should be somewhere in the middle of the display
-   Alg_iterator iterator( &dest->GetSeq(), false );
-   iterator.begin();
-   // for every event
-   Alg_event_ptr evt;
-   int note_count = 0;
-   int pitch_sum = 0;
-   while (NULL != (evt = iterator.next())) {
-      // if the event is a note
-       if (evt->get_type() == 'n') {
-           Alg_note_ptr note = (Alg_note_ptr) evt;
-           pitch_sum += (int) note->pitch;
-           note_count++;
-       }
-   }
-   int mean_pitch = (note_count > 0 ? pitch_sum / note_count : 60);
-   // initial track is about 27 half-steps high; if bottom note is C,
-   // then middle pitch class is D. Round mean_pitch to the nearest D:
-   int mid_pitch = ((mean_pitch - 2 + 6) / 12) * 12 + 2;
-   dest->SetBottomNote(mid_pitch - 14);
-   dest->SetTopNote(mid_pitch + 13);
+
+   dest->ZoomAllNotes();
    return true;
 }
 

src/tracks/playabletrack/notetrack/ui/NoteTrackVZoomHandle.cpp

@@ -147,6 +147,7 @@ HitTestPreview NoteTrackVZoomHandle::Preview
 const int kZoomIn = 6;
 const int kZoomOut = 7;
 const int kZoomReset = 8;
+const int kZoomMax = 9;
 
 enum {
    OnZoomFitVerticalID = 20000,
@@ -164,6 +165,8 @@ enum {
    // Reserve an ample block of ids for spectrum scale types
    OnFirstSpectrumScaleID,
    OnLastSpectrumScaleID = OnFirstSpectrumScaleID + 19,
+
+   OnZoomMaxID,
 };
 ///////////////////////////////////////////////////////////////////////////////
 // Table class
@@ -187,6 +190,7 @@ protected:
 // void OnZoomHalfWave(wxCommandEvent&){ OnZoom( kZoomHalfWave );};
    void OnZoomInVertical(wxCommandEvent&){ OnZoom( kZoomIn );};
    void OnZoomOutVertical(wxCommandEvent&){ OnZoom( kZoomOut );};
+   void OnZoomMax(wxCommandEvent&){ OnZoom( kZoomMax );};
 
 private:
    void DestroyMenu() override
@@ -211,7 +215,7 @@ void NoteTrackVRulerMenuTable::InitMenu(Menu *WXUNUSED(pMenu), void *pUserData)
 void NoteTrackVRulerMenuTable::OnZoom( int iZoomCode ){
    switch( iZoomCode ){
    case kZoomReset:
-      mpData->pTrack->ZoomMaxExtent();
+      mpData->pTrack->ZoomAllNotes();
       break;
    case kZoomIn:
       mpData->pTrack->ZoomIn(mpData->rect, mpData->yy);
@@ -219,7 +223,9 @@ void NoteTrackVRulerMenuTable::OnZoom( int iZoomCode ){
    case kZoomOut:
       mpData->pTrack->ZoomOut(mpData->rect, mpData->yy);
       break;
-
+   case kZoomMax:
+      mpData->pTrack->ZoomMaxExtent();
+      break;
    }
    GetActiveProject()->ModifyState(false);
 }
@@ -228,6 +234,7 @@ void NoteTrackVRulerMenuTable::OnZoom( int iZoomCode ){
 BEGIN_POPUP_MENU(NoteTrackVRulerMenuTable)
 
    POPUP_MENU_ITEM(OnZoomResetID,      _("Zoom Reset\tShift-Right-Click"), OnZoomReset)
+   POPUP_MENU_ITEM(OnZoomMaxID,        _("Max Zoom"), OnZoomMax)
 
    POPUP_MENU_SEPARATOR()
    POPUP_MENU_ITEM(OnZoomInVerticalID,  _("Zoom In\tLeft-Click/Left-Drag"),  OnZoomInVertical)
@@ -296,8 +303,15 @@ UIHandle::Result NoteTrackVZoomHandle::Release
    }
    else if (event.ShiftDown() || event.RightUp()) {
       if (event.ShiftDown() && event.RightUp()) {
-         // Zoom out completely
-         pTrack->ZoomMaxExtent();
+         auto oldBotNote = pTrack->GetBottomNote();
+         auto oldTopNote = pTrack->GetTopNote();
+         // Zoom out to show all notes
+         pTrack->ZoomAllNotes();
+         if (pTrack->GetBottomNote() == oldBotNote &&
+               pTrack->GetTopNote() == oldTopNote) {
+            // However if we are already showing all notes, zoom out further
+            pTrack->ZoomMaxExtent();
+         }
       } else {
          // Zoom out
          pTrack->ZoomOut(evt.rect, mZoomEnd);