further work

Signed-off-by: Jan N. Klug <[email protected]>

bundles/org.openhab.core/src/main/java/org/openhab/core/internal/i18n/I18nProviderImpl.java

@@ -78,6 +78,7 @@
 import org.openhab.core.library.dimension.Density;
 import org.openhab.core.library.dimension.ElectricConductivity;
 import org.openhab.core.library.dimension.Intensity;
+import org.openhab.core.library.dimension.Price;
 import org.openhab.core.library.dimension.VolumetricFlowRate;
 import org.openhab.core.library.types.PointType;
 import org.openhab.core.library.unit.CurrencyProvider;
@@ -398,7 +399,7 @@ public static Map<Class<? extends Quantity<?>>, Map<SystemOfUnits, Unit<? extend
         addDefaultUnit(dimensionMap, Area.class, SIUnits.SQUARE_METRE, ImperialUnits.SQUARE_FOOT);
         addDefaultUnit(dimensionMap, ArealDensity.class, Units.DOBSON_UNIT);
         addDefaultUnit(dimensionMap, CatalyticActivity.class, Units.KATAL);
-        addDefaultUnit(dimensionMap, Currency.class, CurrencyUnits.SYSTEM_CURRENCY);
+        addDefaultUnit(dimensionMap, Currency.class, CurrencyUnits.BASE_CURRENCY);
         addDefaultUnit(dimensionMap, DataAmount.class, Units.BYTE);
         addDefaultUnit(dimensionMap, DataTransferRate.class, Units.MEGABIT_PER_SECOND);
         addDefaultUnit(dimensionMap, Density.class, Units.KILOGRAM_PER_CUBICMETRE);
@@ -424,6 +425,7 @@ public static Map<Class<? extends Quantity<?>>, Map<SystemOfUnits, Unit<? extend
         addDefaultUnit(dimensionMap, Mass.class, SIUnits.KILOGRAM, ImperialUnits.POUND);
         addDefaultUnit(dimensionMap, Power.class, Units.WATT);
         addDefaultUnit(dimensionMap, Pressure.class, HECTO(SIUnits.PASCAL), ImperialUnits.INCH_OF_MERCURY);
+        addDefaultUnit(dimensionMap, Price.class, CurrencyUnits.BASE_PRICE);
         addDefaultUnit(dimensionMap, RadiationDoseAbsorbed.class, Units.GRAY);
         addDefaultUnit(dimensionMap, RadiationDoseEffective.class, Units.SIEVERT);
         addDefaultUnit(dimensionMap, Radioactivity.class, Units.BECQUEREL);

bundles/org.openhab.core/src/main/java/org/openhab/core/internal/library/unit/CurrencyService.java

@@ -12,7 +12,7 @@
  */
 package org.openhab.core.internal.library.unit;
 
-import static org.openhab.core.library.unit.CurrencyUnits.SYSTEM_CURRENCY;
+import static org.openhab.core.library.unit.CurrencyUnits.BASE_CURRENCY;
 
 import java.math.BigDecimal;
 import java.util.Set;
@@ -67,9 +67,9 @@ public void removeCurrencyProvider(CurrencyProvider currencyProvider) {
 
     private synchronized void enableProvider(CurrencyProvider currencyProvider) {
         FACTOR_FCN = currencyProvider.getExchangeRateFunction();
-        ((CurrencyUnit) SYSTEM_CURRENCY).setSymbol(currencyProvider.getBaseCurrency().getSymbol());
-        ((CurrencyUnit) SYSTEM_CURRENCY).setName(currencyProvider.getBaseCurrency().getName());
-        SimpleUnitFormat.getInstance().label(SYSTEM_CURRENCY, currencyProvider.getBaseCurrency().getSymbol());
+        ((CurrencyUnit) BASE_CURRENCY).setSymbol(currencyProvider.getBaseCurrency().getSymbol());
+        ((CurrencyUnit) BASE_CURRENCY).setName(currencyProvider.getBaseCurrency().getName());
+        SimpleUnitFormat.getInstance().label(BASE_CURRENCY, currencyProvider.getBaseCurrency().getSymbol());
         currencyProvider.getCurrencies().forEach(CurrencyUnits::addUnit);
     }
 
@@ -79,7 +79,7 @@ private synchronized void enableProvider(CurrencyProvider currencyProvider) {
      * @param currency the currency
      * @return the exchange rate
      */
-    public static @Nullable BigDecimal getConversionFactor(Unit<Currency> currency) {
+    public static @Nullable BigDecimal getExchangeRate(Unit<Currency> currency) {
         return FACTOR_FCN.apply(currency);
     }
 }

bundles/org.openhab.core/src/main/java/org/openhab/core/library/dimension/Currency.java

@@ -17,7 +17,7 @@
 import org.eclipse.jdt.annotation.NonNullByDefault;
 
 /**
- * The {@link Currency} is a
+ * The {@link Currency} defines the dimension for currencies
  *
  * @author Jan N. Klug - Initial contribution
  */

bundles/org.openhab.core/src/main/java/org/openhab/core/library/dimension/Price.java

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) 2010-2023 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.library.dimension;
+
+import javax.measure.Quantity;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * The {@link Price} defines the dimension for prices
+ *
+ * @author Jan N. Klug - Initial contribution
+ */
+@NonNullByDefault
+public interface Price extends Quantity<Price> {
+}

bundles/org.openhab.core/src/main/java/org/openhab/core/library/unit/CurrencyUnit.java

@@ -16,7 +16,7 @@
 import static org.eclipse.jdt.annotation.DefaultLocation.PARAMETER;
 import static org.eclipse.jdt.annotation.DefaultLocation.RETURN_TYPE;
 import static org.eclipse.jdt.annotation.DefaultLocation.TYPE_BOUND;
-import static org.openhab.core.library.unit.CurrencyUnits.SYSTEM_CURRENCY;
+import static org.openhab.core.library.unit.CurrencyUnits.BASE_CURRENCY;
 import static tech.units.indriya.AbstractUnit.ONE;
 
 import java.io.Serializable;
@@ -191,12 +191,12 @@ private UnitConverter internalGetConverterTo(Unit<Currency> that) throws Unconve
         if (this.equals(that))
             return AbstractConverter.IDENTITY;
 
-        if (SYSTEM_CURRENCY.equals(this)) {
+        if (BASE_CURRENCY.equals(this)) {
             BigDecimal factor = CurrencyService.FACTOR_FCN.apply(that);
             if (factor != null) {
                 return new CurrencyConverter(factor);
             }
-        } else if (SYSTEM_CURRENCY.equals(that)) {
+        } else if (BASE_CURRENCY.equals(that)) {
             BigDecimal factor = CurrencyService.FACTOR_FCN.apply(this);
             if (factor != null) {
                 return new CurrencyConverter(factor).inverse();

bundles/org.openhab.core/src/main/java/org/openhab/core/library/unit/CurrencyUnits.java

@@ -19,9 +19,12 @@
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.library.dimension.Currency;
+import org.openhab.core.library.dimension.Price;
 
 import tech.units.indriya.AbstractSystemOfUnits;
+import tech.units.indriya.AbstractUnit;
 import tech.units.indriya.format.SimpleUnitFormat;
+import tech.units.indriya.unit.ProductUnit;
 
 /**
  * The {@link CurrencyUnits} defines the UoM system for handling currencies
@@ -33,10 +36,12 @@ public final class CurrencyUnits extends AbstractSystemOfUnits {
 
     private static final CurrencyUnits INSTANCE = new CurrencyUnits();
 
-    public static final Unit<Currency> SYSTEM_CURRENCY = new CurrencyUnit("DEF", null);
+    public static final Unit<Currency> BASE_CURRENCY = new CurrencyUnit("DEF", null);
+    public static Unit<Price> BASE_PRICE = new ProductUnit<>(AbstractUnit.ONE.divide(BASE_CURRENCY));
 
     static {
-        addUnit(SYSTEM_CURRENCY);
+        addUnit(BASE_CURRENCY);
+        INSTANCE.units.add(BASE_PRICE);
     }
 
     @Override