[Units]Allow querying schema for unit of measure

src/Base/UnitsApi.cpp

@@ -163,6 +163,11 @@ bool UnitsApi::isMultiUnitAngle()
     return UserPrefSystem->isMultiUnitAngle();
 }
 
+std::string UnitsApi::getBasicLengthUnit()
+{
+    return UserPrefSystem->getBasicLengthUnit();
+}
+
 // === static translation methods ==========================================
 
 QString UnitsApi::schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString)

src/Base/UnitsApi.h

@@ -98,6 +98,9 @@ public:
     //return true if the current user schema uses multiple units for angles (ex. DMS)
     static bool isMultiUnitAngle();
 
+    //return the basic unit of measure for length in the current user schema.
+    static std::string getBasicLengthUnit();
+
     // Python interface
     static PyMethodDef    Methods[];
 

src/Base/UnitsSchema.h

@@ -71,6 +71,9 @@ public:
 
     //return true if this schema uses multiple units for angles (ex. DMS)
     virtual bool isMultiUnitAngle() const {return false;}
+
+    //return the basic length unit for this schema
+    virtual std::string getBasicLengthUnit() const { return std::string("mm"); }
 };
 
 

src/Base/UnitsSchemaCentimeters.h

@@ -37,6 +37,8 @@ class UnitsSchemaCentimeters: public UnitsSchema
 {
 public:
     QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString) override;
+
+    std::string getBasicLengthUnit() const override { return std::string("cm"); }
 };
 
 } // namespace Base

src/Base/UnitsSchemaImperial1.h

@@ -41,6 +41,7 @@ public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
     QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString) override;
+    std::string getBasicLengthUnit() const override { return std::string("in"); }
 };
 
 /** The schema class for the imperial unit system
@@ -53,6 +54,7 @@ public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
     QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString) override;
+    std::string getBasicLengthUnit() const override { return std::string("in"); }
 };
 
 /** The schema class for the imperial unit system
@@ -65,6 +67,7 @@ public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
     QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString) override;
+    std::string getBasicLengthUnit() const override { return std::string("ft"); }
 
     //return true if this schema uses multiple units for length (ex. Ft/In)
     bool isMultiUnitLength() const override {return true;}
@@ -81,6 +84,7 @@ public:
     //virtual void setSchemaUnits(void);
     //virtual void resetSchemaUnits(void);
     QString schemaTranslate(const Base::Quantity& quant, double &factor, QString &unitString) override;
+    std::string getBasicLengthUnit() const override { return std::string("ft"); }
 
     //return true if this schema uses multiple units for angles (ex. DMS)
     bool isMultiUnitAngle() const override {return true;}