comparison layer/Layer.h @ 267:4ed1446ad604

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

     virtual bool getCrosshairExtents(View *, QPainter &, QPoint /* cursorPos */,
                                      std::vector<QRect> &) const {
         return false;
     }
     virtual void paintCrosshairs(View *, QPainter &, QPoint) const { }
+
+    virtual void paintMeasurementRects(View *, QPainter &) const;
 
     virtual QString getFeatureDescription(View *, QPoint &) const {
 	return "";
     }
 

 
     virtual void editStart(View *, QMouseEvent *) { }
     virtual void editDrag(View *, QMouseEvent *) { }
     virtual void editEnd(View *, QMouseEvent *) { }
 
+    // Measurement rectangle (or equivalent).  Unlike draw and edit,
+    // the base Layer class can provide working implementations of
+    // these for most situations.
+    //
+    virtual void measureStart(View *, QMouseEvent *);
+    virtual void measureDrag(View *, QMouseEvent *);
+    virtual void measureEnd(View *, QMouseEvent *);
+
     /**
      * Open an editor on the item under the mouse (e.g. on
      * double-click).  If there is no item or editing is not
      * supported, return false.
      */

      * Return the value and unit at the given x coordinate in the
      * given view.  This is for descriptive purposes using the
      * measurement tool.  The default implementation works correctly
      * if the layer hasTimeXAxis().
      */
-    virtual bool getXScaleValue(View *v, int x,
+    virtual bool getXScaleValue(const View *v, int x,
                                 float &value, QString &unit) const;
 
     /** 
      * Return the value and unit at the given y coordinate in the
      * given view.
      */
-    virtual bool getYScaleValue(View *, int /* y */,
+    virtual bool getYScaleValue(const View *, int /* y */,
                                 float &/* value */, QString &/* unit */) const {
         return false;
     }
 
     /**

     void layerParameterRangesChanged();
     void layerNameChanged();
 
     void verticalZoomChanged();
 
+protected:
+    struct MeasureRect {
+        mutable QRect pixrect;
+        long startFrame; // only valid for a layer that hasTimeXAxis
+        long endFrame;   // ditto
+    };
+
+    typedef std::vector<MeasureRect> MeasureRectList; // should be x-ordered
+    MeasureRectList m_measureRectList;
+    MeasureRect m_draggingRect;
+    bool m_haveDraggingRect;
+
 private:
     mutable QMutex m_dormancyMutex;
     mutable std::map<const void *, bool> m_dormancy;
 };