More restructuring of Ruler update code

src/NumberScale.h

@@ -24,6 +24,7 @@ enum NumberScaleType {
    nstPeriod,
 
    nstNumScaleTypes,
+   nstNone,
 };
 
 
@@ -31,7 +32,7 @@ class NumberScale
 {
 public:
    NumberScale()
-      : mType(nstLinear), mValue0(0), mValue1(1)
+      : mType(nstNone), mValue0(0), mValue1(1)
    {}
 
    NumberScale(NumberScaleType type, float value0, float value1)
@@ -39,6 +40,7 @@ public:
    {
       switch (mType) {
       case nstLinear:
+      case nstNone:
       {
          mValue0 = value0;
          mValue1 = value1;
@@ -156,6 +158,7 @@ public:
       default:
          wxASSERT(false);
       case nstLinear:
+      case nstNone:
          return mValue0 + pp * (mValue1 - mValue0);
       case nstLogarithmic:
          return exp(mValue0 + pp * (mValue1 - mValue0));
@@ -186,6 +189,7 @@ public:
          default:
             wxASSERT(false);
          case nstLinear:
+         case nstNone:
          case nstLogarithmic:
             return mValue;
          case nstMel:
@@ -203,6 +207,7 @@ public:
       {
          switch (mType) {
          case nstLinear:
+         case nstNone:
          case nstMel:
          case nstBark:
          case nstErb:
@@ -230,6 +235,7 @@ public:
       default:
          wxASSERT(false);
       case nstLinear:
+      case nstNone:
       case nstMel:
       case nstBark:
       case nstErb:
@@ -253,6 +259,7 @@ public:
       default:
          wxASSERT(false);
       case nstLinear:
+      case nstNone:
          return ((val - mValue0) / (mValue1 - mValue0));
       case nstLogarithmic:
          return ((log(val) - mValue0) / (mValue1 - mValue0));

src/tracks/playabletrack/wavetrack/ui/SpectrumVRulerControls.cpp

@@ -193,7 +193,7 @@ void SpectrumVRulerControls::DoUpdateVRuler(
          NumberScale scale(
             wt->GetSpectrogramSettings().GetScale( minFreq, maxFreq )
                .Reversal() );
-         vruler->SetNumberScale(&scale);
+         vruler->SetNumberScale(scale);
       }
          break;
    }

src/tracks/playabletrack/wavetrack/ui/WaveformVZoomHandle.cpp

@@ -120,7 +120,6 @@ void WaveformVZoomHandle::DoZoom(
    const float halfrate = rate / 2;
    float maxFreq = 8000.0;
    const SpectrogramSettings &specSettings = pTrack->GetSpectrogramSettings();
-   NumberScale scale;
 
    bool bDragZoom = WaveTrackVZoomHandle::IsDragZooming(zoomStart, zoomEnd);
    // Add 100 if spectral to separate the kinds of zoom.

src/widgets/Ruler.h

@@ -12,6 +12,7 @@
 #define __AUDACITY_RULER__
 
 #include "wxPanelWrapper.h" // to inherit
+#include "../NumberScale.h" // member variable
 
 #include <wx/colour.h> // member variable
 #include <wx/pen.h> // member variable
@@ -20,7 +21,6 @@ class wxArrayString;
 class wxDC;
 class wxFont;
 
-class NumberScale;
 class Envelope;
 class ZoomInfo;
 
@@ -102,11 +102,9 @@ class AUDACITY_DLL_API Ruler {
       wxFont major, minor, minorMinor;
       int lead;
    };
-   Fonts GetFonts() const
-   { return mFonts; }
+   Fonts GetFonts() const;
 
-   // Copies *pScale if it is not NULL
-   void SetNumberScale(const NumberScale *pScale);
+   void SetNumberScale(const NumberScale &scale);
 
    // The ruler will not draw text within this (pixel) range.
    // Use this if you have another graphic object obscuring part
@@ -140,12 +138,12 @@ class AUDACITY_DLL_API Ruler {
    //
 
    // Note that it will not erase for you...
-   void Draw(wxDC& dc);
-   void Draw(wxDC& dc, const Envelope* envelope);
+   void Draw(wxDC& dc) const;
+   void Draw(wxDC& dc, const Envelope* envelope) const;
    // If length <> 0, draws lines perpendiculars to ruler corresponding
    // to selected ticks (major, minor, or both), in an adjacent window.
    // You may need to use the offsets if you are using part of the dc for rulers, borders etc.
-   void DrawGrid(wxDC& dc, int length, bool minor = true, bool major = true, int xOffset = 0, int yOffset = 0);
+   void DrawGrid(wxDC& dc, int length, bool minor = true, bool major = true, int xOffset = 0, int yOffset = 0) const;
 
    // So we can have white ticks on black...
    void SetTickColour( const wxColour & colour)
@@ -170,16 +168,15 @@ class AUDACITY_DLL_API Ruler {
 
    using Bits = std::vector< bool >;
 
-   static void ChooseFonts( Fonts &fonts, wxDC &dc, int desiredPixelHeight );
-   void Update( wxDC &dc, const Envelope* envelope );
+   void ChooseFonts( wxDC &dc ) const;
+
+   void UpdateCache( wxDC &dc, const Envelope* envelope ) const;
 
-   struct TickOutputs;
    struct Updater;
    
 public:
    bool mbTicksOnly; // true => no line the length of the ruler
    bool mbTicksAtExtremes;
-   wxRect mRect;
 
 private:
    wxColour mTickColour;
@@ -188,16 +185,13 @@ private:
    int          mLeft, mTop, mRight, mBottom;
    int          mLength;
 
-   Fonts mFonts;
-   bool         mUserFonts;
+   std::unique_ptr<Fonts> mpUserFonts;
+   mutable std::unique_ptr<Fonts> mpFonts;
 
    double       mMin, mMax;
    double       mHiddenMin, mHiddenMax;
 
    Bits mUserBits;
-   Bits mBits;
-
-   bool         mValid;
 
    static std::pair< wxRect, Label > MakeTick(
       Label lab,
@@ -206,17 +200,14 @@ private:
       int left, int top, int spacing, int lead,
       bool flip, int orientation );
 
-   Labels mMajorLabels;
-   Labels mMinorLabels;
-   Labels mMinorMinorLabels;
+   struct Cache;
+   mutable std::unique_ptr<Cache> mpCache;
 
    // Returns 'zero' label coordinate (for grid drawing)
-   int FindZero( const Labels &labels );
+   int FindZero( const Labels &labels ) const;
 
-   public:
-   int GetZeroPosition();
+   int GetZeroPosition() const;
 
-   private:
    int          mOrientation;
    int          mSpacing;
    double       mDbMirrorValue;
@@ -227,15 +218,12 @@ private:
    bool         mFlip;
    bool         mCustom;
    bool         mbMinor;
-   bool         mMajorGrid;      //  for grid drawing
-   bool         mMinorGrid;      //         .
-   int          mGridLineLength; //        end
    TranslatableString mUnits;
    bool         mTwoTone;
    const ZoomInfo *mUseZoomInfo;
    int          mLeftOffset;
 
-   std::unique_ptr<NumberScale> mpNumberScale;
+   NumberScale mNumberScale;
 };
 
 class AUDACITY_DLL_API RulerPanel final : public wxPanelWrapper {