[Major] Updates to Parameter interface

li.strolch.model/src/main/java/li/strolch/model/parameter/BooleanParameter.java

@@ -73,13 +73,18 @@ public class BooleanParameter extends AbstractParameter<Boolean> {
 	/**
 	 * Sets the value to false
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value = false;
 	}
 
+	@Override
+	public boolean isEmpty() {
+		return !this.value;
+	}
+
 	@Override
 	public String getType() {
 		return StrolchValueType.BOOLEAN.getType();

li.strolch.model/src/main/java/li/strolch/model/parameter/DateParameter.java

@@ -28,6 +28,7 @@ import li.strolch.utils.iso8601.ISO8601FormatFactory;
 public class DateParameter extends AbstractParameter<Date> {
 
 	private static final long serialVersionUID = 0L;
+	private static final Date EMPTY_VALUE = ISO8601FormatFactory.getInstance().getDateFormat().parse("-");
 
 	private Date value;
 
@@ -75,11 +76,16 @@ public class DateParameter extends AbstractParameter<Date> {
 	/**
 	 * Sets the value to 1970-01-01 (unix time 0)
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
-		this.value = ISO8601FormatFactory.getInstance().getDateFormat().parse("-");
+		this.value = EMPTY_VALUE;
+	}
+
+	@Override
+	public boolean isEmpty() {
+		return this.value.equals(EMPTY_VALUE);
 	}
 
 	@Override

li.strolch.model/src/main/java/li/strolch/model/parameter/DurationParameter.java

@@ -68,13 +68,18 @@ public class DurationParameter extends AbstractParameter<Long> {
 	/**
 	 * Sets the value to 0
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value = 0L;
 	}
 
+	@Override
+	public boolean isEmpty() {
+		return this.value == 0L;
+	}
+
 	@Override
 	public void setValueFromString(String valueAsString) {
 		setValue(parseFromString(valueAsString));

li.strolch.model/src/main/java/li/strolch/model/parameter/FloatListParameter.java

@@ -107,12 +107,12 @@ public class FloatListParameter extends AbstractParameter<List<Double>> implemen
 	}
 
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value.clear();
 	}
 
 	@Override
-	public boolean isValueEmpty() {
+	public boolean isEmpty() {
 		return this.value.isEmpty();
 	}
 

li.strolch.model/src/main/java/li/strolch/model/parameter/FloatParameter.java

@@ -69,13 +69,18 @@ public class FloatParameter extends AbstractParameter<Double> {
 	/**
 	 * Sets the value to 0
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value = 0.0D;
 	}
 
+	@Override
+	public boolean isEmpty() {
+		return this.value == 0.0D;
+	}
+
 	@Override
 	public void setValueFromString(String valueAsString) {
 		setValue(parseFromString(valueAsString));

li.strolch.model/src/main/java/li/strolch/model/parameter/IntegerListParameter.java

@@ -107,12 +107,12 @@ public class IntegerListParameter extends AbstractParameter<List<Integer>> imple
 	}
 
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value.clear();
 	}
 
 	@Override
-	public boolean isValueEmpty() {
+	public boolean isEmpty() {
 		return this.value.isEmpty();
 	}
 

li.strolch.model/src/main/java/li/strolch/model/parameter/IntegerParameter.java

@@ -73,13 +73,18 @@ public class IntegerParameter extends AbstractParameter<Integer> {
 	/**
 	 * Sets the value to 0
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value = 0;
 	}
 
+	@Override
+	public boolean isEmpty() {
+		return this.value == 0;
+	}
+
 	@Override
 	public void setValueFromString(String valueAsString) {
 		setValue(parseFromString(valueAsString));

li.strolch.model/src/main/java/li/strolch/model/parameter/ListParameter.java

@@ -48,12 +48,12 @@ public interface ListParameter<E> extends Parameter<List<E>> {
 	/**
 	 * Clears the list of values, i.e the list of values is empty after this call
 	 */
-	public void clearValue();
+	public void clear();
 
 	/**
 	 * Returns true if the list of values is empty, false if not
 	 * 
 	 * @returns true if the list of values is empty, false if not
 	 */
-	public boolean isValueEmpty();
+	public boolean isEmpty();
 }

li.strolch.model/src/main/java/li/strolch/model/parameter/LongListParameter.java

@@ -107,12 +107,12 @@ public class LongListParameter extends AbstractParameter<List<Long>> implements
 	}
 
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value.clear();
 	}
 
 	@Override
-	public boolean isValueEmpty() {
+	public boolean isEmpty() {
 		return this.value.isEmpty();
 	}
 

li.strolch.model/src/main/java/li/strolch/model/parameter/LongParameter.java

@@ -68,13 +68,18 @@ public class LongParameter extends AbstractParameter<Long> {
 	/**
 	 * Sets the value to 0
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value = 0L;
 	}
 
+	@Override
+	public boolean isEmpty() {
+		return this.value == 0L;
+	}
+
 	@Override
 	public void setValueFromString(String valueAsString) {
 		setValue(parseFromString(valueAsString));

li.strolch.model/src/main/java/li/strolch/model/parameter/Parameter.java

@@ -45,7 +45,7 @@ public interface Parameter<T> extends StrolchElement, Comparable<Parameter<?>> {
 	 * 
 	 * @return
 	 */
-	public <U extends T>  U getValue();
+	public <U extends T> U getValue();
 
 	/**
 	 * the value of the parameter
@@ -57,7 +57,13 @@ public interface Parameter<T> extends StrolchElement, Comparable<Parameter<?>> {
 	/**
 	 * Clears the value, dependent on the concrete class
 	 */
-	public void clearValue();
+	public void clear();
+
+	/**
+	 * @return true if the value is empty, i.e. if the value is the same as the value which would be set if
+	 *         {@link #clear()} was called
+	 */
+	public boolean isEmpty();
 
 	/**
 	 * get the hidden attribute

li.strolch.model/src/main/java/li/strolch/model/parameter/StringListParameter.java

@@ -107,12 +107,12 @@ public class StringListParameter extends AbstractParameter<List<String>> impleme
 	}
 
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value.clear();
 	}
 
 	@Override
-	public boolean isValueEmpty() {
+	public boolean isEmpty() {
 		return this.value.isEmpty();
 	}
 

li.strolch.model/src/main/java/li/strolch/model/parameter/StringParameter.java

@@ -74,10 +74,10 @@ public class StringParameter extends AbstractParameter<String> {
 	/**
 	 * Sets the value to the empty string
 	 * 
-	 * @see Parameter#clearValue()
+	 * @see Parameter#clear()
 	 */
 	@Override
-	public void clearValue() {
+	public void clear() {
 		this.value = "";
 	}
 

li.strolch.model/src/test/java/li/strolch/model/ModelTest.java

@@ -482,7 +482,7 @@ public class ModelTest {
 		assertEquals("a, b", stringListP.getValueAsString());
 		stringListP.setValueFromString("a,b");
 		assertEquals("a, b", stringListP.getValueAsString());
-		stringListP.clearValue();
+		stringListP.clear();
 		assertEquals("", stringListP.getValueAsString());
 		stringListP.addValue("a");
 		assertEquals("a", stringListP.getValueAsString());
@@ -499,7 +499,7 @@ public class ModelTest {
 		assertEquals("4, 45", intListP.getValueAsString());
 		intListP.setValueFromString("4,45");
 		assertEquals("4, 45", intListP.getValueAsString());
-		intListP.clearValue();
+		intListP.clear();
 		assertEquals("", intListP.getValueAsString());
 		intListP.addValue(55);
 		assertEquals("55", intListP.getValueAsString());
@@ -516,7 +516,7 @@ public class ModelTest {
 		assertEquals("4.2, 4.1", floatListP.getValueAsString());
 		floatListP.setValueFromString("4.2,4.1");
 		assertEquals("4.2, 4.1", floatListP.getValueAsString());
-		floatListP.clearValue();
+		floatListP.clear();
 		assertEquals("", floatListP.getValueAsString());
 		floatListP.addValue(55.5);
 		assertEquals("55.5", floatListP.getValueAsString());
@@ -533,7 +533,7 @@ public class ModelTest {
 		assertEquals("4, 4", longListP.getValueAsString());
 		longListP.setValueFromString("4,4");
 		assertEquals("4, 4", longListP.getValueAsString());
-		longListP.clearValue();
+		longListP.clear();
 		assertEquals("", longListP.getValueAsString());
 		longListP.addValue(55L);
 		assertEquals("55", longListP.getValueAsString());