add posibility to use a unit schema other then the system schema to represent a quantity

src/Base/Quantity.cpp

@@ -213,6 +213,11 @@ QString Quantity::getUserString(double& factor, QString& unitString) const
     return Base::UnitsApi::schemaTranslate(*this, factor, unitString);
 }
 
+QString Quantity::getUserString(UnitsSchema* schema, double &factor, QString &unitString) const
+{
+    return schema->schemaTranslate(*this, factor, unitString);
+}
+
 /// true if it has a number without a unit
 bool Quantity::isDimensionless(void)const
 {

src/Base/Quantity.h

@@ -35,6 +35,7 @@
 #endif
 
 namespace Base {
+class UnitsSchema;
 
 struct BaseExport QuantityFormat {
     enum NumberOption {
@@ -143,12 +144,13 @@ public:
         _Format = f;
     }
     /// transfer to user preferred unit/potence
-    QString getUserString(double &factor, QString &unitString)const;
+    QString getUserString(double &factor, QString &unitString) const;
     QString getUserString(void) const { // to satisfy GCC
         double  dummy1;
         QString dummy2;
         return getUserString(dummy1,dummy2);
     }
+    QString getUserString(UnitsSchema* schema, double &factor, QString &unitString) const;
 
     static Quantity parse(const QString &string);
 

src/Base/UnitsApi.h

@@ -86,7 +86,6 @@ public:
 
     static double defaultFactor;
 
-protected:
     /// return an instance of the given enum value
     static UnitsSchemaPtr createSchema(UnitSystem s);
 

src/Gui/QuantitySpinBox.cpp

@@ -231,6 +231,7 @@ end:
     double maximum;
     double minimum;
     double singleStep;
+    std::unique_ptr<Base::UnitsSchema> scheme;
 };
 }
 
@@ -373,7 +374,7 @@ void Gui::QuantitySpinBox::onChange()
             std::stringstream s;
             s << value->getValue();
 
-            lineEdit()->setText(value->getQuantity().getUserString());
+            lineEdit()->setText(getUserString(value->getQuantity()));
             setReadOnly(true);
             QPixmap pixmap = getIcon(":/icons/bound-expression.svg", QSize(iconHeight, iconHeight));
             iconLabel->setPixmap(pixmap);
@@ -488,7 +489,7 @@ void QuantitySpinBox::updateText(const Quantity &quant)
     Q_D(QuantitySpinBox);
 
     double dFactor;
-    QString txt = quant.getUserString(dFactor,d->unitStr);
+    QString txt = getUserString(quant, dFactor, d->unitStr);
     d->unitValue = quant.getValue()/dFactor;
     lineEdit()->setText(txt);
 }
@@ -566,7 +567,7 @@ void QuantitySpinBox::userInput(const QString & text)
     }
 
     double factor;
-    res.getUserString(factor,d->unitStr);
+    getUserString(res, factor, d->unitStr);
     d->unitValue = res.getValue()/factor;
     d->quantity = res;
 
@@ -697,6 +698,44 @@ void QuantitySpinBox::setDecimals(int v)
     updateText(d->quantity);
 }
 
+void QuantitySpinBox::setSchema(const Base::UnitSystem& s)
+{
+    Q_D(QuantitySpinBox);
+    d->scheme = Base::UnitsApi::createSchema(s);
+    updateText(d->quantity);
+}
+
+void QuantitySpinBox::clearSchema()
+{
+    Q_D(QuantitySpinBox);
+    d->scheme = nullptr;
+    updateText(d->quantity);
+}
+
+QString QuantitySpinBox::getUserString(const Base::Quantity& val, double& factor, QString& unitString) const
+{
+    Q_D(const QuantitySpinBox);
+    if (d->scheme) {
+        return val.getUserString(d->scheme.get(), factor, unitString);
+    }
+    else {
+        return val.getUserString(factor, unitString);
+    }
+}
+
+QString QuantitySpinBox::getUserString(const Base::Quantity& val) const
+{
+    Q_D(const QuantitySpinBox);
+    if (d->scheme) {
+        double factor;
+        QString unitString;
+        return val.getUserString(d->scheme.get(), factor, unitString);
+    }
+    else {
+        return val.getUserString();
+    }
+}
+
 QAbstractSpinBox::StepEnabled QuantitySpinBox::stepEnabled() const
 {
     Q_D(const QuantitySpinBox);
@@ -827,7 +866,7 @@ QString QuantitySpinBox::textFromValue(const Base::Quantity& value) const
 {
     double factor;
     QString unitStr;
-    QString str = value.getUserString(factor, unitStr);
+    QString str = getUserString(value, factor, unitStr);
     if (qAbs(value.getValue()) >= 1000.0) {
         str.remove(locale().groupSeparator());
     }

src/Gui/QuantitySpinBox.h

@@ -25,6 +25,7 @@
 #define GUI_QUANTITYSPINBOX_H
 
 #include <QAbstractSpinBox>
+#include <Base/UnitsSchema.h>
 #include <Gui/MetaTypes.h>
 #include "ExpressionBinding.h"
 
@@ -96,6 +97,13 @@ public:
     /// Sets the number of decimals
     void setDecimals(int v);
 
+    /// Sets a specific unit schema to handle quantities.
+    /// The system-wide schema won't be used any more.
+    void setSchema(const Base::UnitSystem& s);
+
+    /// Clears the schemaand again use the system-wide schema.
+    void clearSchema();
+
     /// Gets the path of the bound property
     QString boundToName() const;
     /// Sets the path of the bound property
@@ -146,6 +154,8 @@ protected:
 
 private:
     void updateText(const Base::Quantity&);
+    QString getUserString(const Base::Quantity& val, double& factor, QString& unitString) const;
+    QString getUserString(const Base::Quantity& val) const;
 
 Q_SIGNALS:
     /** Gets emitted if the user has entered a VALID input