+
+ // 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());
+}
+
+bool SketchPlugin_ConstraintDistance::compute(const std::string& theAttributeId)
+{
+ if (theAttributeId != SketchPlugin_Constraint::FLYOUT_VALUE_PNT())
+ return false;
+
+ if (!sketch())
+ return false;
+
+ DataPtr aData = data();
+ std::shared_ptr<GeomDataAPI_Point2D> aPoint_A = getFeaturePoint(
+ aData, SketchPlugin_Constraint::ENTITY_A());
+ std::shared_ptr<GeomDataAPI_Point2D> aPoint_B = getFeaturePoint(
+ aData, SketchPlugin_Constraint::ENTITY_B());
+
+ std::shared_ptr<GeomAPI_Pnt2d> aPnt_A;
+ std::shared_ptr<GeomAPI_Pnt2d> aPnt_B;
+
+ if (aPoint_A && aPoint_B) {
+ aPnt_A = aPoint_A->pnt();
+ aPnt_B = aPoint_B->pnt();
+ } else if (!aPoint_A && aPoint_B) {
+ std::shared_ptr<SketchPlugin_Line> aLine = getFeatureLine(
+ aData, SketchPlugin_Constraint::ENTITY_A());
+ if (aLine) {
+ aPnt_B = aPoint_B->pnt();
+ aPnt_A = getProjectionPoint(aLine, aPnt_B);
+ }
+ } else if (aPoint_A && !aPoint_B) {
+ std::shared_ptr<SketchPlugin_Line> aLine = getFeatureLine(
+ aData, SketchPlugin_Constraint::ENTITY_B());
+ if (aLine) {
+ aPnt_A = aPoint_A->pnt();
+ aPnt_B = getProjectionPoint(aLine, aPnt_A);
+ }
+ }
+ if (!aPnt_A || !aPnt_B)
+ return false;
+
+ std::shared_ptr<GeomDataAPI_Point2D> aFlyOutAttr = std::dynamic_pointer_cast<
+ GeomDataAPI_Point2D>(aData->attribute(theAttributeId));
+
+ std::shared_ptr<GeomAPI_Pnt> aPoint1 = sketch()->to3D(aPnt_A->x(), aPnt_A->y());
+ std::shared_ptr<GeomAPI_Pnt> aPoint2 = sketch()->to3D(aPnt_B->x(), aPnt_B->y());
+ // it is not possible to create lin2d on the points with equal position
+ if (aPoint1->distance(aPoint1) < tolerance)
+ return false;
+
+ std::shared_ptr<GeomAPI_Lin2d> aLine = std::shared_ptr<GeomAPI_Lin2d>(new GeomAPI_Lin2d(aPnt_A, aPnt_B));
+ double aDist = aPoint1->distance(aPoint2)/5.;
+ std::shared_ptr<GeomAPI_Pnt2d> aFPnt = aLine->shiftedLocation(aDist);
+ aFlyOutAttr->setValue(aFPnt);
+
+ return true;