[TD]expose dimension arrow position to Python

src/Mod/TechDraw/App/DrawViewDimension.cpp

@@ -1093,7 +1093,20 @@ bool DrawViewDimension::leaderIntersectsArc(Base::Vector3d s, Base::Vector3d poi
     return result;
 }
 
-//are there non-blank references?
+void DrawViewDimension::saveArrowPositions(const Base::Vector2d positions[])
+{
+    double scale = getViewPart()->getScale();
+    m_arrowPositions.first = Base::Vector3d(positions[0].x, positions[0].y, 0.0) / scale;
+    m_arrowPositions.second = Base::Vector3d(positions[1].x, positions[1].y, 0.0) / scale;
+}
+
+//return position within parent view of dimension arrow heads/dimline endpoints
+//note positions are in apparent coord (inverted y).
+pointPair DrawViewDimension::getArrowPositions(void)
+{
+    return m_arrowPositions;
+}
+
 bool DrawViewDimension::has2DReferences(void) const
 {
 //    Base::Console().Message("DVD::has2DReferences() - %s\n",getNameInDocument());

src/Mod/TechDraw/App/DrawViewDimension.h

@@ -153,6 +153,9 @@ public:
 
     bool isMultiValueSchema(void) const;
 
+    pointPair getArrowPositions(void);
+    void saveArrowPositions(const Base::Vector2d positions[]);
+
 protected:
     virtual void onChanged(const App::Property* prop) override;
     virtual void onDocumentRestored() override;
@@ -174,6 +177,7 @@ protected:
     pointPair closestPoints(TopoDS_Shape s1,
                             TopoDS_Shape s2) const;
     pointPair   m_linearPoints;
+    pointPair   m_arrowPositions;
 
 private:
     static const char* TypeEnums[];

src/Mod/TechDraw/App/DrawViewDimensionPy.xml

@@ -33,6 +33,11 @@
         <UserDocu>getAnglePoints() - returns list of points for angle Dimension</UserDocu>
       </Documentation>
     </Methode>
+    <Methode Name="getArrowPositions">
+      <Documentation>
+        <UserDocu>getArrowPositions() - returns list of locations or Dimension Arrowheads. Locations are in unscaled coordinates of parent View </UserDocu>
+      </Documentation>
+    </Methode>
     <CustomAttributes />
   </PythonExport>
 </GenerateModel>

src/Mod/TechDraw/App/DrawViewDimensionPyImp.cpp

@@ -99,6 +99,16 @@ PyObject* DrawViewDimensionPy::getAnglePoints(PyObject* args)
     return ret;
 }
 
+PyObject* DrawViewDimensionPy::getArrowPositions(PyObject* args)
+{
+    (void) args;
+    DrawViewDimension* dvd = getDrawViewDimensionPtr();
+    pointPair pts = dvd->getArrowPositions();
+    PyObject* ret = PyList_New(0);
+    PyList_Append(ret,new Base::VectorPy(new Base::Vector3d(pts.first)));
+    PyList_Append(ret,new Base::VectorPy(new Base::Vector3d(pts.second)));
+    return ret;
+}
 PyObject *DrawViewDimensionPy::getCustomAttributes(const char* /*attr*/) const
 {
     return 0;

src/Mod/TechDraw/Gui/QGIViewDimension.cpp

@@ -1176,6 +1176,8 @@ void QGIViewDimension::drawArrows(int count, const Base::Vector2d positions[], d
     const int arrowCount = 2;
     QGIArrow *arrows[arrowCount] = { aHead1, aHead2 };
 
+    arrowPositionsToFeature(positions);
+
     for (int i = 0; i < arrowCount; ++i) {
         QGIArrow *arrow = arrows[i];
 
@@ -1198,6 +1200,15 @@ void QGIViewDimension::drawArrows(int count, const Base::Vector2d positions[], d
     }
 }
 
+void QGIViewDimension::arrowPositionsToFeature(const Base::Vector2d positions[]) const
+{
+    auto dim( dynamic_cast<TechDraw::DrawViewDimension*>(getViewObject()) );
+    if( dim == nullptr )
+        return;
+
+    dim->saveArrowPositions(positions);
+}
+
 void QGIViewDimension::drawSingleLine(QPainterPath &painterPath, const Base::Vector2d &lineOrigin, double lineAngle,
                                       double startPosition, double endPosition) const
 {

src/Mod/TechDraw/Gui/QGIViewDimension.h

@@ -260,6 +260,8 @@ protected:
     //QGICMark* centerMark
     double m_lineWidth;
 
+    void arrowPositionsToFeature(const Base::Vector2d positions[]) const;
+
 private:
     static inline Base::Vector2d fromQtApp(const Base::Vector3d &v) { return Base::Vector2d(v.x, -v.y); }
     static inline Base::BoundBox2d fromQtGui(const QRectF &r)