added some documentation

src/main/java/de/neemann/digital/core/basic/And.java

@@ -9,12 +9,22 @@ import de.neemann.digital.core.element.ElementTypeDescription;
 import java.util.ArrayList;
 
 /**
+ * The And gate
+ *
  * @author hneemann
  */
 public class And extends Function {
 
+    /**
+     * The And description
+     */
     public static final ElementTypeDescription DESCRIPTION = new FanInDescription(And.class);
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public And(ElementAttributes attributes) {
         super(attributes.get(AttributeKey.Bits));
     }

src/main/java/de/neemann/digital/core/basic/FanIn.java

@@ -10,46 +10,61 @@ import java.util.ArrayList;
 import static de.neemann.digital.core.element.PinInfo.input;
 
 /**
+ * A fan in. Used as base class for the simple bool operations
+ *
  * @author hneemann
  */
 public abstract class FanIn extends Node implements Element {
 
-    protected final ArrayList<ObservableValue> inputs;
-    protected final ObservableValue output;
+    private final ArrayList<ObservableValue> inputs;
+    private final ObservableValue output;
     private final int bits;
 
+    /**
+     * Creates a new instance
+     *
+     * @param bits the number of bits
+     */
     public FanIn(int bits) {
         this.bits = bits;
         inputs = new ArrayList<>();
         output = new ObservableValue("out", bits);
     }
 
-    public ObservableValue getOutput() {
-        return output;
-    }
-
     @Override
     public void setInputs(ObservableValue... in) throws NodeException {
         for (ObservableValue v : in)
             inputs.add(v.checkBits(bits, this).addObserverToValue(this));
     }
 
+    /**
+     * @return the outputs
+     */
+    public ObservableValue getOutput() {
+        return output;
+    }
+
+    /**
+     * @return the outputs
+     */
+    public ArrayList<ObservableValue> getInputs() {
+        return inputs;
+    }
+
     @Override
     public ObservableValue[] getOutputs() {
         return new ObservableValue[]{output};
     }
 
-    public static class FanInDescription extends ElementTypeDescription {
-        public FanInDescription(Class<? extends Element> clazz) {
+    /**
+     * The fan in description
+     */
+    static class FanInDescription extends ElementTypeDescription {
+        FanInDescription(Class<? extends Element> clazz) {
             super(clazz);
             addAttributes();
         }
 
-        public FanInDescription(String name, ElementFactory elementFactory) {
-            super(name, elementFactory);
-            addAttributes();
-        }
-
         private void addAttributes() {
             addAttribute(AttributeKey.Rotate);
             addAttribute(AttributeKey.Bits);

src/main/java/de/neemann/digital/core/basic/Function.java

@@ -8,23 +8,24 @@ import java.util.ArrayList;
 /**
  * @author hneemann
  */
-public abstract class Function extends FanIn {
+abstract class Function extends FanIn {
 
     private long value;
 
-    public Function(int bits) {
+    Function(int bits) {
         super(bits);
     }
 
     @Override
     public void readInputs() throws NodeException {
-        value = calculate(inputs);
+        value = calculate(getInputs());
     }
 
     @Override
     public void writeOutputs() throws NodeException {
-        output.setValue(value);
+        getOutput().setValue(value);
     }
 
     protected abstract int calculate(ArrayList<ObservableValue> inputs) throws NodeException;
+
 }

src/main/java/de/neemann/digital/core/basic/NAnd.java

@@ -9,12 +9,21 @@ import de.neemann.digital.core.element.ElementTypeDescription;
 import java.util.ArrayList;
 
 /**
+ * The NAnd
  * @author hneemann
  */
 public class NAnd extends Function {
 
+    /**
+     * The NAnd description
+     */
     public static final ElementTypeDescription DESCRIPTION = new FanInDescription(NAnd.class);
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public NAnd(ElementAttributes attributes) {
         super(attributes.get(AttributeKey.Bits));
     }

src/main/java/de/neemann/digital/core/basic/NOr.java

@@ -9,12 +9,21 @@ import de.neemann.digital.core.element.ElementTypeDescription;
 import java.util.ArrayList;
 
 /**
+ * The NOr
  * @author hneemann
  */
 public class NOr extends Function {
 
+    /**
+     * The NOr description
+     */
     public static final ElementTypeDescription DESCRIPTION = new FanInDescription(NOr.class);
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public NOr(ElementAttributes attributes) {
         super(attributes.get(AttributeKey.Bits));
     }

src/main/java/de/neemann/digital/core/basic/Not.java

@@ -11,10 +11,15 @@ import de.neemann.digital.core.element.ElementTypeDescription;
 import static de.neemann.digital.core.element.PinInfo.input;
 
 /**
+ * The Not
+ *
  * @author hneemann
  */
 public class Not extends Node implements Element {
 
+    /**
+     * The Not description
+     */
     public static final ElementTypeDescription DESCRIPTION = new ElementTypeDescription(Not.class, input("in"))
             .addAttribute(AttributeKey.Rotate)
             .addAttribute(AttributeKey.Bits);
@@ -24,6 +29,11 @@ public class Not extends Node implements Element {
     private ObservableValue input;
     private long value;
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public Not(ElementAttributes attributes) {
         bits = attributes.get(AttributeKey.Bits);
         output = new ObservableValue("out", bits);
@@ -39,10 +49,6 @@ public class Not extends Node implements Element {
         output.setValue(~value);
     }
 
-    public ObservableValue getOutput() {
-        return output;
-    }
-
     @Override
     public void setInputs(ObservableValue... inputs) throws NodeException {
         input = inputs[0].addObserverToValue(this).checkBits(bits, this);

src/main/java/de/neemann/digital/core/basic/Or.java

@@ -9,12 +9,21 @@ import de.neemann.digital.core.element.ElementTypeDescription;
 import java.util.ArrayList;
 
 /**
+ * The Or
  * @author hneemann
  */
 public class Or extends Function {
 
+    /**
+     * The And description
+     */
     public static final ElementTypeDescription DESCRIPTION = new FanInDescription(Or.class);
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public Or(ElementAttributes attributes) {
         super(attributes.get(AttributeKey.Bits));
     }

src/main/java/de/neemann/digital/core/basic/XNOr.java

@@ -8,15 +8,24 @@ import de.neemann.digital.core.element.ElementTypeDescription;
 import static de.neemann.digital.core.element.PinInfo.input;
 
 /**
+ * The XNOr
  * @author hneemann
  */
 public class XNOr extends XOr {
 
+    /**
+     * The XNOr description
+     */
     public static final ElementTypeDescription DESCRIPTION
             = new ElementTypeDescription(XNOr.class, input("a"), input("b"))
             .addAttribute(AttributeKey.Rotate)
             .addAttribute(AttributeKey.Bits);
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public XNOr(ElementAttributes attributes) {
         super(attributes);
     }

src/main/java/de/neemann/digital/core/basic/XOr.java

@@ -16,6 +16,9 @@ import static de.neemann.digital.core.element.PinInfo.input;
  */
 public class XOr extends Node implements Element {
 
+    /**
+     * The XOr description
+     */
     public static final ElementTypeDescription DESCRIPTION
             = new ElementTypeDescription(XOr.class, input("a"), input("b"))
             .addAttribute(AttributeKey.Rotate)
@@ -27,6 +30,11 @@ public class XOr extends Node implements Element {
     protected ObservableValue b;
     protected long value;
 
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the attributes
+     */
     public XOr(ElementAttributes attributes) {
         bits = attributes.get(AttributeKey.Bits);
         this.out = new ObservableValue("out", bits);

src/main/java/de/neemann/digital/core/basic/package-info.java

@@ -0,0 +1,6 @@
+/**
+ * The simple boolean operation like and, or and not
+ *
+ * @author hneemann
+ */
+package de.neemann.digital.core.basic;

src/main/java/de/neemann/digital/core/wiring/Multiplexer.java

@@ -47,12 +47,12 @@ public class Multiplexer extends FanIn {
     @Override
     public void readInputs() throws NodeException {
         int n = (int) selector.getValue();
-        value = inputs.get(n).getValue();
+        value = getInputs().get(n).getValue();
     }
 
     @Override
     public void writeOutputs() throws NodeException {
-        output.setValue(value);
+        getOutput().setValue(value);
     }
 
     @Override

src/test/java/de/neemann/digital/FlipFlopsTest.java

@@ -85,9 +85,9 @@ public class FlipFlopsTest extends TestCase {
 
 
         FanIn a3 = model.add(new And(attr));
-        a3.setInputs(nor1.getOutput(), not.getOutput());
+        a3.setInputs(nor1.getOutput(), not.getOutputs()[0]);
         FanIn a4 = model.add(new And(attr));
-        a4.setInputs(nor2.getOutput(), not.getOutput());
+        a4.setInputs(nor2.getOutput(), not.getOutputs()[0]);
 
         nor3.setInputs(a3.getOutput(), nor4.getOutput());
         nor4.setInputs(a4.getOutput(), nor3.getOutput());