comparison layer/SpectrogramLayer.h @ 267:4ed1446ad604

* more on measurement tool -- pull out some logic from pane to layer &c
  still more to do

     }
 
     virtual bool isLayerOpaque() const { return true; }
     virtual bool isLayerColourSignificant() const { return true; }
 
-    float getYForFrequency(View *v, float frequency) const;
-    float getFrequencyForY(View *v, int y) const;
+    float getYForFrequency(const View *v, float frequency) const;
+    float getFrequencyForY(const View *v, int y) const;
 
     virtual int getCompletion(View *v) const;
 
     virtual bool getValueExtents(float &min, float &max,
                                  bool &logarithmic, QString &unit) const;
 
     virtual bool getDisplayExtents(float &min, float &max) const;
 
     virtual bool setDisplayExtents(float min, float max);
 
-    virtual bool getYScaleValue(View *, int, float &, QString &) const;
+    virtual bool getYScaleValue(const View *, int, float &, QString &) const;
 
     virtual QString toXmlString(QString indent = "",
 				QString extraAttributes = "") const;
 
     void setProperties(const QXmlAttributes &attributes);