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Make SHAPER STUDY fields exported in SMESH into MED file
[modules/shaper.git] / src / SketchPlugin / SketchPlugin_ConstraintAngle.cpp
index fc2df7237bdaff1f5d4e2bf46c68e13c9aa7b8aa..bf2f211d96b99f99ce15e407a27ef176135e3147 100644 (file)
@@ -1,15 +1,35 @@
-// Copyright (C) 2014-20xx CEA/DEN, EDF R&D -->
-
-// File:    SketchPlugin_ConstraintAngle.cpp
-// Created: 19 August 2015
-// Author:  Artem ZHIDKOV
+// Copyright (C) 2014-2019  CEA/DEN, EDF R&D
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+//
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
 
 #include "SketchPlugin_ConstraintAngle.h"
 #include <SketchPlugin_Line.h>
+#include <SketchPlugin_Tools.h>
+#include <SketcherPrs_Tools.h>
 
 #include <ModelAPI_AttributeDouble.h>
+#include <ModelAPI_AttributeInteger.h>
+#include <ModelAPI_Session.h>
+#include <ModelAPI_Validator.h>
+
 #include <GeomDataAPI_Point2D.h>
 
+#include <GeomAPI_Angle2d.h>
 #include <GeomAPI_Dir2d.h>
 #include <GeomAPI_Lin2d.h>
 #include <GeomAPI_Pnt2d.h>
 #include <SketcherPrs_Factory.h>
 #include <SketcherPrs_Tools.h>
 
+#include <cmath>
+#include <regex>
+#include <sstream>
+
 const double tolerance = 1.e-7;
 #define PI 3.1415926535897932
 
+/// \brief Calculate intersection point of two lines
+static std::shared_ptr<GeomAPI_Pnt2d> intersect(FeaturePtr theLine1, FeaturePtr theLine2);
+
 
 SketchPlugin_ConstraintAngle::SketchPlugin_ConstraintAngle()
 {
@@ -29,23 +56,65 @@ SketchPlugin_ConstraintAngle::SketchPlugin_ConstraintAngle()
 
 void SketchPlugin_ConstraintAngle::initAttributes()
 {
+  ModelAPI_ValidatorsFactory* aValidators = ModelAPI_Session::get()->validators();
+
   data()->addAttribute(SketchPlugin_Constraint::VALUE(), ModelAPI_AttributeDouble::typeId());
   data()->addAttribute(SketchPlugin_Constraint::ENTITY_A(), ModelAPI_AttributeRefAttr::typeId());
   data()->addAttribute(SketchPlugin_Constraint::ENTITY_B(), ModelAPI_AttributeRefAttr::typeId());
   data()->addAttribute(SketchPlugin_Constraint::FLYOUT_VALUE_PNT(), GeomDataAPI_Point2D::typeId());
+
+  data()->addAttribute(ANGLE_VALUE_ID(), ModelAPI_AttributeDouble::typeId());
+  data()->addAttribute(TYPE_ID(), ModelAPI_AttributeInteger::typeId());
+
+  data()->addAttribute(ANGLE_REVERSED_FIRST_LINE_ID(), ModelAPI_AttributeBoolean::typeId());
+  data()->addAttribute(ANGLE_REVERSED_SECOND_LINE_ID(), ModelAPI_AttributeBoolean::typeId());
+
+  data()->addAttribute(LOCATION_TYPE_ID(), ModelAPI_AttributeInteger::typeId());
+  aValidators->registerNotObligatory(getKind(), LOCATION_TYPE_ID());
+
+  data()->addAttribute(SELECTED_FIRST_POINT_ID(), GeomDataAPI_Point2D::typeId());
+  data()->attribute(SELECTED_FIRST_POINT_ID())->setIsArgument(false);
+  aValidators->registerNotObligatory(getKind(), SELECTED_FIRST_POINT_ID());
+
+  data()->addAttribute(SELECTED_SECOND_POINT_ID(), GeomDataAPI_Point2D::typeId());
+  data()->attribute(SELECTED_SECOND_POINT_ID())->setIsArgument(false);
+  aValidators->registerNotObligatory(getKind(), SELECTED_SECOND_POINT_ID());
+
+  if (attribute(TYPE_ID())->isInitialized())
+    myPrevAngleType = integer(TYPE_ID())->value();
+  else
+    myPrevAngleType = (int)SketcherPrs_Tools::ANGLE_DIRECT;
+}
+
+void SketchPlugin_ConstraintAngle::colorConfigInfo(std::string& theSection, std::string& theName,
+                                                   std::string& theDefault)
+{
+  theSection = "Visualization";
+  theName = "sketch_dimension_color";
+  theDefault = SKETCH_DIMENSION_COLOR;
 }
 
 void SketchPlugin_ConstraintAngle::execute()
 {
   std::shared_ptr<ModelAPI_Data> aData = data();
-  AttributeDoublePtr anAttrValue = std::dynamic_pointer_cast<ModelAPI_AttributeDouble>(
-      aData->attribute(SketchPlugin_Constraint::VALUE()));
 
-  if(anAttrValue->isInitialized())
+  AttributeRefAttrPtr anAttrA = aData->refattr(SketchPlugin_Constraint::ENTITY_A());
+  AttributeRefAttrPtr anAttrB = aData->refattr(SketchPlugin_Constraint::ENTITY_B());
+  if (!anAttrA->isInitialized() || !anAttrB->isInitialized())
     return;
 
-  double anAngle = calculateAngle();
-  anAttrValue->setValue(anAngle);
+  AttributeDoublePtr anAttrValue = real(ANGLE_VALUE_ID());
+  if (!anAttrValue->isInitialized())
+    calculateAngle();
+
+  // the value should to be computed here, not in the
+  // getAISObject in order to change the model value
+  // inside the object transaction. This is important for creating a constraint by preselection.
+  // The display of the presentation in this case happens after the transaction commit
+  std::shared_ptr<GeomDataAPI_Point2D> aFlyOutAttr = std::dynamic_pointer_cast<
+      GeomDataAPI_Point2D>(aData->attribute(SketchPlugin_Constraint::FLYOUT_VALUE_PNT()));
+  if(!aFlyOutAttr->isInitialized())
+    compute(SketchPlugin_Constraint::FLYOUT_VALUE_PNT());
 }
 
 AISObjectPtr SketchPlugin_ConstraintAngle::getAISObject(AISObjectPtr thePrevious)
@@ -53,98 +122,271 @@ AISObjectPtr SketchPlugin_ConstraintAngle::getAISObject(AISObjectPtr thePrevious
   if (!sketch())
     return thePrevious;
 
-  AISObjectPtr anAIS = thePrevious;
-  if (!anAIS) {
-    anAIS = SketcherPrs_Factory::angleConstraint(this, sketch()->coordinatePlane());
-  }
-
-  // Set color from preferences
-  std::vector<int> aRGB = Config_PropManager::color("Visualization", "sketch_dimension_color",
-                                                    SKETCH_DIMENSION_COLOR);
-  anAIS->setColor(aRGB[0], aRGB[1], aRGB[2]);
+  AISObjectPtr anAIS = SketcherPrs_Factory::angleConstraint(this, sketch(),
+                                                            thePrevious);
+  if (anAIS.get() && !thePrevious.get())
+    SketchPlugin_Tools::setDimensionColor(anAIS);
   return anAIS;
 }
 
 void SketchPlugin_ConstraintAngle::attributeChanged(const std::string& theID)
 {
-  if (theID == SketchPlugin_Constraint::ENTITY_A() || 
-      theID == SketchPlugin_Constraint::ENTITY_B()) {
+  std::shared_ptr<ModelAPI_Data> aData = data();
+  if (!aData)
+    return;
+
+  if (theID == TYPE_ID())
+    updateAngleValue();
+
+  FeaturePtr aLineA = SketcherPrs_Tools::getFeatureLine(aData, ENTITY_A());
+  FeaturePtr aLineB = SketcherPrs_Tools::getFeatureLine(aData, ENTITY_B());
+  if (!aLineA || !aLineB)
+    return;
+
+  if (theID == ENTITY_A() || theID == ENTITY_B() ||
+      theID == TYPE_ID() || theID == ANGLE_VALUE_ID()) {
+    calculateAngle();
+  } else if (theID == FLYOUT_VALUE_PNT() && !myFlyoutUpdate) {
+    // Recalculate flyout point in local coordinates
+    // coordinates are calculated according to the center of shapes intersection
+    std::shared_ptr<GeomDataAPI_Point2D> aFlyoutAttr =
+      std::dynamic_pointer_cast<GeomDataAPI_Point2D>(attribute(FLYOUT_VALUE_PNT()));
+
     std::shared_ptr<ModelAPI_Data> aData = data();
-    if (!aData)
+    std::shared_ptr<GeomAPI_Ax3> aPlane = SketchPlugin_Sketch::plane(sketch());
+
+    // Intersection of lines
+    std::shared_ptr<GeomAPI_Pnt2d> anInter = intersect(aLineA, aLineB);
+    if (!anInter)
       return;
-  FeaturePtr aLineA = SketcherPrs_Tools::getFeatureLine(aData, SketchPlugin_Constraint::ENTITY_A());
-  FeaturePtr aLineB = SketcherPrs_Tools::getFeatureLine(aData, SketchPlugin_Constraint::ENTITY_B());
-    if (!aLineA || !aLineB)
+
+    myFlyoutUpdate = true;
+    std::shared_ptr<GeomAPI_XY> aFlyoutDir = aFlyoutAttr->pnt()->xy()->decreased(anInter->xy());
+    if (aFlyoutDir->dot(aFlyoutDir) < tolerance * tolerance)
+      aFlyoutAttr->setValue(aFlyoutAttr->x() + tolerance, aFlyoutAttr->y());
+    myFlyoutUpdate = false;
+  }
+}
+
+void SketchPlugin_ConstraintAngle::calculateAngle()
+{
+  // update *_REVERSED_* flags
+  calculateAnglePosition();
+
+  std::shared_ptr<ModelAPI_Data> aData = data();
+  std::shared_ptr<GeomAPI_Ax3> aPlane = SketchPlugin_Sketch::plane(sketch());
+  FeaturePtr aLineA = SketcherPrs_Tools::getFeatureLine(aData, ENTITY_A());
+  FeaturePtr aLineB = SketcherPrs_Tools::getFeatureLine(aData, ENTITY_B());
+
+  GeomPnt2dPtr aStartA = SketcherPrs_Tools::getPoint(aLineA.get(), SketchPlugin_Line::START_ID());
+  GeomPnt2dPtr aEndA = SketcherPrs_Tools::getPoint(aLineA.get(), SketchPlugin_Line::END_ID());
+  GeomPnt2dPtr aStartB = SketcherPrs_Tools::getPoint(aLineB.get(), SketchPlugin_Line::START_ID());
+  GeomPnt2dPtr aEndB = SketcherPrs_Tools::getPoint(aLineB.get(), SketchPlugin_Line::END_ID());
+
+  std::shared_ptr<GeomAPI_Lin2d> aLine1(new GeomAPI_Lin2d(aStartA, aEndA));
+  std::shared_ptr<GeomAPI_Lin2d> aLine2(new GeomAPI_Lin2d(aStartB, aEndB));
+
+  bool isReversed1 = boolean(ANGLE_REVERSED_FIRST_LINE_ID())->value();
+  bool isReversed2 = boolean(ANGLE_REVERSED_SECOND_LINE_ID())->value();
+
+  std::shared_ptr<GeomAPI_Angle2d> anAng(
+      new GeomAPI_Angle2d(aLine1, isReversed1, aLine2, isReversed2));
+  double anAngle = anAng->angleDegree();
+
+  AttributeDoublePtr anAngleValueAttr = real(ANGLE_VALUE_ID());
+  if (!anAngleValueAttr->isInitialized())
+    anAngleValueAttr->setValue(getAngleForType(fabs(anAngle)));
+
+  anAngle /= fabs(anAngle);
+  anAngle *= getAngleForType(anAngleValueAttr->value());
+
+  // update value of the constraint to be passed to the solver
+  real(SketchPlugin_Constraint::VALUE())->setValue(anAngle);
+}
+
+void SketchPlugin_ConstraintAngle::calculateAnglePosition()
+{
+  if (attribute(ANGLE_REVERSED_FIRST_LINE_ID())->isInitialized() &&
+      attribute(ANGLE_REVERSED_SECOND_LINE_ID())->isInitialized())
+    return; // already calculated
+
+  DataPtr aData = data();
+  FeaturePtr aLineA = SketcherPrs_Tools::getFeatureLine(aData, ENTITY_A());
+  FeaturePtr aLineB = SketcherPrs_Tools::getFeatureLine(aData, ENTITY_B());
+
+  GeomPnt2dPtr aStartA = SketcherPrs_Tools::getPoint(aLineA.get(), SketchPlugin_Line::START_ID());
+  GeomPnt2dPtr aEndA = SketcherPrs_Tools::getPoint(aLineA.get(), SketchPlugin_Line::END_ID());
+  GeomPnt2dPtr aStartB = SketcherPrs_Tools::getPoint(aLineB.get(), SketchPlugin_Line::START_ID());
+  GeomPnt2dPtr aEndB = SketcherPrs_Tools::getPoint(aLineB.get(), SketchPlugin_Line::END_ID());
+
+  bool isReversed1 = false;
+  bool isReversed2 = false;
+
+  GeomPnt2dPtr aSelected1 = SketcherPrs_Tools::getPoint(this, SELECTED_FIRST_POINT_ID());
+  GeomPnt2dPtr aSelected2 = SketcherPrs_Tools::getPoint(this, SELECTED_SECOND_POINT_ID());
+  if (aSelected1 && aSelected2) {
+    GeomPnt2dPtr anInterPnt = intersect(aLineA, aLineB);
+    if (!anInterPnt)
       return;
+    std::shared_ptr<GeomAPI_XY> anInterXY = anInterPnt->xy();
+    isReversed1 = aSelected1->xy()->decreased(anInterXY)->dot(
+                  aEndA->xy()->decreased(aStartA->xy())) < -tolerance;
+    isReversed2 = aSelected2->xy()->decreased(anInterXY)->dot(
+                  aEndB->xy()->decreased(aStartB->xy())) < -tolerance;
+  }
+  else {
+    // no point is selected (document opened or Python script is loaded),
+    // calculate basing on the value
+    std::shared_ptr<GeomAPI_Angle2d> anAng(new GeomAPI_Angle2d(aStartA, aEndA, aStartB, aEndB));
+    isReversed1 = anAng->isReversed(0);
+    isReversed2 = anAng->isReversed(1);
+  }
+
+  // adjust reversed flags according to the angle type
+  AttributeIntegerPtr aTypeAttr = integer(TYPE_ID());
+  if (aTypeAttr && aTypeAttr->isInitialized() &&
+     (SketcherPrs_Tools::AngleType)(aTypeAttr->value()) == SketcherPrs_Tools::ANGLE_COMPLEMENTARY)
+    isReversed1 = !isReversed1;
+
+  boolean(ANGLE_REVERSED_FIRST_LINE_ID())->setValue(isReversed1);
+  boolean(ANGLE_REVERSED_SECOND_LINE_ID())->setValue(isReversed2);
+}
+
+static double angleForType(const double theAngle, const int theType)
+{
+  double anAngle = theAngle;
+  switch ((SketcherPrs_Tools::AngleType)theType) {
+    case SketcherPrs_Tools::ANGLE_DIRECT:
+      anAngle = theAngle;
+      break;
+    case SketcherPrs_Tools::ANGLE_COMPLEMENTARY:
+      anAngle = 180.0 - theAngle;
+      break;
+    case SketcherPrs_Tools::ANGLE_BACKWARD:
+      anAngle = 360.0 - theAngle;
+      break;
+    default:
+      break;
+  }
+  return anAngle;
+}
 
-    std::shared_ptr<ModelAPI_AttributeDouble> aValueAttr = std::dynamic_pointer_cast<
-        ModelAPI_AttributeDouble>(data()->attribute(SketchPlugin_Constraint::VALUE()));
-    if (!aValueAttr->isInitialized()) { // only if it is not initialized, try to compute the current value
-      double anAngle = calculateAngle();
-      aValueAttr->setValue(anAngle);
+double SketchPlugin_ConstraintAngle::getAngleForType(double theAngle)
+{
+  return angleForType(theAngle, integer(TYPE_ID())->value());
+}
+
+void SketchPlugin_ConstraintAngle::updateAngleValue()
+{
+  AttributeIntegerPtr anAngleType = integer(TYPE_ID());
+  AttributeDoublePtr anAngleValueAttr = real(ANGLE_VALUE_ID());
+  if (anAngleValueAttr->isInitialized()) {
+    if (anAngleValueAttr->text().empty()) {
+      // calculate value related to the type twice:
+      // the first time - to return to direct angle,
+      // the second time - to apply new type
+      double aValue = angleForType(anAngleValueAttr->value(), myPrevAngleType);
+      aValue = angleForType(aValue, anAngleType->value());
+      anAngleValueAttr->setValue(aValue);
+    }
+    else {
+      // process the parametric value
+      std::string anAngleText = anAngleValueAttr->text();
+      std::regex anAngleRegex("\\s*([-+]?[0-9]*\\.?[0-9]*)\\s*([-+])\\s*\\((.*)\\)",
+                              std::regex_constants::ECMAScript);
+
+      double anAnglePrefix = 0.0;
+      static const char aSignPrefix[2] = { '-', '+' };
+      int aSignInd = 1;
+
+      std::smatch aResult;
+      if (std::regex_search(anAngleText, aResult, anAngleRegex)) {
+        anAnglePrefix = std::atof(aResult[1].str().c_str());
+        aSignInd = aResult[2].str()[0] == aSignPrefix[0] ? 0 : 1;
+        anAngleText = aResult[3].str();
+      }
+
+      if (myPrevAngleType != SketcherPrs_Tools::ANGLE_DIRECT)
+        aSignInd = 1 - aSignInd;
+      anAnglePrefix = angleForType(anAnglePrefix, myPrevAngleType);
+
+      if (anAngleType->value() != SketcherPrs_Tools::ANGLE_DIRECT)
+        aSignInd = 1 - aSignInd;
+      anAnglePrefix = angleForType(anAnglePrefix, anAngleType->value());
+
+      std::ostringstream aText;
+      bool isPrintSign = true;
+      if (fabs(anAnglePrefix) > tolerance)
+        aText << anAnglePrefix;
+      else
+        isPrintSign = aSignInd == 0;
+      if (isPrintSign)
+        aText << " " << aSignPrefix[aSignInd] << " (";
+      aText << anAngleText << (isPrintSign ? ")" : "");
+      anAngleValueAttr->setText(aText.str());
     }
-  } else if (theID == SketchPlugin_Constraint::FLYOUT_VALUE_PNT() && !myFlyoutUpdate) {
-    // Recalculate flyout point in local coordinates
-    std::shared_ptr<GeomDataAPI_Point2D> aFlyoutAttr =
-        std::dynamic_pointer_cast<GeomDataAPI_Point2D>(attribute(SketchPlugin_Constraint::FLYOUT_VALUE_PNT()));
   }
+  myPrevAngleType = anAngleType->value();
 }
 
-double SketchPlugin_ConstraintAngle::calculateAngle()
+bool SketchPlugin_ConstraintAngle::compute(const std::string& theAttributeId)
 {
-  double anAngle = 0.0;
+  if (theAttributeId != SketchPlugin_Constraint::FLYOUT_VALUE_PNT())
+    return false;
+  if (!sketch())
+    return false;
 
-  std::shared_ptr<ModelAPI_Data> aData = data();
+  std::shared_ptr<GeomDataAPI_Point2D> aFlyOutAttr = std::dynamic_pointer_cast<
+                           GeomDataAPI_Point2D>(attribute(theAttributeId));
+  if (aFlyOutAttr->isInitialized() &&
+      (fabs(aFlyOutAttr->x()) >= tolerance || fabs(aFlyOutAttr->y()) >= tolerance))
+    return false;
+
+  DataPtr aData = data();
   std::shared_ptr<GeomAPI_Ax3> aPlane = SketchPlugin_Sketch::plane(sketch());
   FeaturePtr aLineA = SketcherPrs_Tools::getFeatureLine(aData, SketchPlugin_Constraint::ENTITY_A());
   FeaturePtr aLineB = SketcherPrs_Tools::getFeatureLine(aData, SketchPlugin_Constraint::ENTITY_B());
 
+  if ((aLineA.get() == NULL) || (aLineB.get() == NULL))
+    return false;
+
   // Start and end points of lines
-  std::shared_ptr<GeomDataAPI_Point2D> aPointA1 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aLineA->attribute(SketchPlugin_Line::START_ID()));
-  std::shared_ptr<GeomDataAPI_Point2D> aPointA2 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aLineA->attribute(SketchPlugin_Line::END_ID()));
-
-  std::shared_ptr<GeomDataAPI_Point2D> aPointB1 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aLineB->attribute(SketchPlugin_Line::START_ID()));
-  std::shared_ptr<GeomDataAPI_Point2D> aPointB2 = std::dynamic_pointer_cast<GeomDataAPI_Point2D>(
-      aLineB->attribute(SketchPlugin_Line::END_ID()));
-
-  std::shared_ptr<GeomAPI_Pnt2d> aStartA = aPointA1->pnt();
-  std::shared_ptr<GeomAPI_Pnt2d> aEndA   = aPointA2->pnt();
-  std::shared_ptr<GeomAPI_Pnt2d> aStartB = aPointB1->pnt();
-  std::shared_ptr<GeomAPI_Pnt2d> aEndB   = aPointB2->pnt();
-  if (aStartA->distance(aEndA) < tolerance || aStartB->distance(aEndB) < tolerance)
-    return anAngle;
+  GeomPnt2dPtr aStartA = SketcherPrs_Tools::getPoint(aLineA.get(), SketchPlugin_Line::START_ID());
+  GeomPnt2dPtr aEndA   = SketcherPrs_Tools::getPoint(aLineA.get(), SketchPlugin_Line::END_ID());
+  if (aStartA->distance(aEndA) < tolerance)
+    return false;
 
-  // Lines and their intersection point
-  std::shared_ptr<GeomAPI_Lin2d> aLA(new GeomAPI_Lin2d(aStartA, aEndA));
-  std::shared_ptr<GeomAPI_Lin2d> aLB(new GeomAPI_Lin2d(aStartB, aEndB));
-  std::shared_ptr<GeomAPI_Pnt2d> anInter = aLA->intersect(aLB);
-  if (!anInter)
-    return anAngle;
-
-  // Directions of lines
-  if (anInter->distance(aEndA) < tolerance)
-    aEndA = aStartA;
-  if (anInter->distance(aEndB) < tolerance)
-    aEndB = aStartB;
-  std::shared_ptr<GeomAPI_Dir2d> aDirA(new GeomAPI_Dir2d(aEndA->xy()->decreased(anInter->xy())));
-  std::shared_ptr<GeomAPI_Dir2d> aDirB(new GeomAPI_Dir2d(aEndB->xy()->decreased(anInter->xy())));
-
-  anAngle = aDirA->angle(aDirB) * 180.0 / PI;
-  return anAngle;
+  GeomPnt2dPtr aStartB = SketcherPrs_Tools::getPoint(aLineB.get(), SketchPlugin_Line::START_ID());
+  GeomPnt2dPtr aEndB   = SketcherPrs_Tools::getPoint(aLineB.get(), SketchPlugin_Line::END_ID());
+  if (aStartB->distance(aEndB) < tolerance)
+    return false;
+
+  myFlyoutUpdate = true;
+  double aX = (aStartA->x() + aEndA->x() + aStartB->x() + aEndB->x()) / 4.;
+  double aY = (aStartA->y() + aEndA->y() + aStartB->y() + aEndB->y()) / 4.;
+
+  aFlyOutAttr->setValue(aX, aY);
+  myFlyoutUpdate = false;
+
+  return true;
 }
 
-void SketchPlugin_ConstraintAngle::move(double theDeltaX, double theDeltaY)
+
+// ===============   Auxiliary functions   ==================================
+std::shared_ptr<GeomAPI_Pnt2d> intersect(FeaturePtr theLine1, FeaturePtr theLine2)
 {
-  std::shared_ptr<ModelAPI_Data> aData = data();
-  if (!aData->isValid())
-    return;
+  // Start and end points of lines
+  const std::string& aLineStartAttr = SketchPlugin_Line::START_ID();
+  const std::string& aLineEndAttr = SketchPlugin_Line::END_ID();
+  GeomPnt2dPtr aStartA = SketcherPrs_Tools::getPoint(theLine1.get(), aLineStartAttr);
+  GeomPnt2dPtr aEndA   = SketcherPrs_Tools::getPoint(theLine1.get(), aLineEndAttr);
+  GeomPnt2dPtr aStartB = SketcherPrs_Tools::getPoint(theLine2.get(), aLineStartAttr);
+  GeomPnt2dPtr aEndB   = SketcherPrs_Tools::getPoint(theLine2.get(), aLineEndAttr);
+  if (aStartA->distance(aEndA) < tolerance || aStartB->distance(aEndB) < tolerance)
+    std::shared_ptr<GeomAPI_Pnt2d>();
 
-  myFlyoutUpdate = true;
-  std::shared_ptr<GeomDataAPI_Point2D> aFlyoutAttr = std::dynamic_pointer_cast<
-      GeomDataAPI_Point2D>(aData->attribute(SketchPlugin_Constraint::FLYOUT_VALUE_PNT()));
-  aFlyoutAttr->setValue(aFlyoutAttr->x() + theDeltaX, aFlyoutAttr->y() + theDeltaY);
-  myFlyoutUpdate = false;
+  // Lines and their intersection point
+  std::shared_ptr<GeomAPI_Lin2d> aLA(new GeomAPI_Lin2d(aStartA, aEndA));
+  std::shared_ptr<GeomAPI_Lin2d> aLB(new GeomAPI_Lin2d(aStartB, aEndB));
+  return aLA->intersect(aLB);
 }