App: Implement Save() & Restore() for int/float constraint properties

Implement the methods Save() and Restore() for PropertyIntegerConstraint and PropertyFloatConstraint. Handle also the case of a user-defined ranges.

This fixes https://github.com/FreeCAD/FreeCAD/issues/24571.

Hint: For PropertyQuantityConstraint this is not doable because it doesn't support user-defined ranges

src/App/PropertyStandard.cpp

@@ -770,6 +770,54 @@ void PropertyIntegerConstraint::setPyObject(PyObject* value)
     }
 }
 
+void PropertyIntegerConstraint::Save(Base::Writer& writer) const
+{
+    writer.Stream() << writer.ind()
+                    << "<Integer value=\"" << _lValue << "\"";
+    if (_ConstStruct && _ConstStruct->isDeletable()) {
+        long minimum = _ConstStruct->LowerBound;
+        long maximum = _ConstStruct->UpperBound;
+        long stepsize = _ConstStruct->StepSize;
+        writer.Stream() << " min=\"" << minimum << "\""
+                        << " max=\"" << maximum << "\""
+                        << " step=\"" << stepsize << "\"";
+    }
+    writer.Stream() << "/>\n";
+}
+
+void PropertyIntegerConstraint::Restore(Base::XMLReader& reader)
+{
+    // read my Element
+    reader.readElement("Integer");
+    // get the value of my Attribute
+    setValue(reader.getAttributeAsInteger("value"));
+
+    bool createConstraint = false;
+    long minimum = std::numeric_limits<int>::lowest();
+    long maximum = std::numeric_limits<int>::max();
+    long stepsize = 1.0;
+    if (reader.hasAttribute("min")) {
+        minimum = reader.getAttributeAsInteger("min");
+        createConstraint = true;
+    }
+    if (reader.hasAttribute("max")) {
+        maximum = reader.getAttributeAsInteger("max");
+        createConstraint = true;
+    }
+    if (reader.hasAttribute("step")) {
+        stepsize = reader.getAttributeAsInteger("step");
+    }
+
+    if (createConstraint) {
+        Constraints* c = new Constraints();
+        c->setDeletable(true);
+        c->LowerBound = minimum;
+        c->UpperBound = maximum;
+        c->StepSize = stepsize;
+        setConstraints(c);
+    }
+}
+
 //**************************************************************************
 //**************************************************************************
 // PropertyPercent
@@ -1272,6 +1320,54 @@ void PropertyFloatConstraint::setPyObject(PyObject* value)
     }
 }
 
+void PropertyFloatConstraint::Save(Base::Writer& writer) const
+{
+    writer.Stream() << writer.ind()
+                    << "<Float value=\"" << _dValue << "\"";
+    if (_ConstStruct && _ConstStruct->isDeletable()) {
+        double minimum = _ConstStruct->LowerBound;
+        double maximum = _ConstStruct->UpperBound;
+        double stepsize = _ConstStruct->StepSize;
+        writer.Stream() << " min=\"" << minimum << "\""
+                        << " max=\"" << maximum << "\""
+                        << " step=\"" << stepsize << "\"";
+    }
+    writer.Stream() << "/>\n";
+}
+
+void PropertyFloatConstraint::Restore(Base::XMLReader& reader)
+{
+    // read my Element
+    reader.readElement("Float");
+    // get the value of my Attribute
+    setValue(reader.getAttributeAsFloat("value"));
+
+    bool createConstraint = false;
+    double minimum = std::numeric_limits<double>::lowest();
+    double maximum = std::numeric_limits<double>::max();
+    double stepsize = 1.0;
+    if (reader.hasAttribute("min")) {
+        minimum = reader.getAttributeAsFloat("min");
+        createConstraint = true;
+    }
+    if (reader.hasAttribute("max")) {
+        maximum = reader.getAttributeAsFloat("max");
+        createConstraint = true;
+    }
+    if (reader.hasAttribute("step")) {
+        stepsize = reader.getAttributeAsFloat("step");
+    }
+
+    if (createConstraint) {
+        Constraints* c = new Constraints();
+        c->setDeletable(true);
+        c->LowerBound = minimum;
+        c->UpperBound = maximum;
+        c->StepSize = stepsize;
+        setConstraints(c);
+    }
+}
+
 //**************************************************************************
 // PropertyPrecision
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

src/App/PropertyStandard.h

@@ -339,6 +339,9 @@ public:
     }
     void setPyObject(PyObject* py) override;
 
+    void Save(Base::Writer& writer) const override;
+    void Restore(Base::XMLReader& reader) override;
+
 protected:
     const Constraints* _ConstStruct {nullptr};
 };
@@ -673,6 +676,9 @@ public:
 
     void setPyObject(PyObject* py) override;
 
+    void Save(Base::Writer& writer) const override;
+    void Restore(Base::XMLReader& reader) override;
+
 protected:
     const Constraints* _ConstStruct {nullptr};
 };