added some comments

src/main/java/de/neemann/digital/gui/draw/shapes/GenericShape.java

@@ -8,6 +8,9 @@ import de.neemann.digital.gui.draw.parts.Pins;
 import de.neemann.digital.gui.draw.parts.State;
 
 /**
+ * Universal Shape. Used for most components.
+ * Shows a simple Box with inputs at the left and outputs at the right.
+ *
  * @author hneemann
  */
 public class GenericShape implements Shape {

src/main/java/de/neemann/digital/gui/draw/shapes/Interactor.java

@@ -5,6 +5,11 @@ import de.neemann.digital.gui.draw.graphics.Vector;
 import de.neemann.digital.gui.draw.parts.State;
 
 /**
+ * The VisualParts Interactor instance is called if the part is clicked
+ * during execution. So the User can interakt with the part during execution.
+ * Used at the InputShape to let the user toggle the inputs state.
+ *
+ * @see InputShape
  * @author hneemann
  */
 public interface Interactor {

src/main/java/de/neemann/digital/gui/draw/shapes/ProbeShape.java

@@ -15,7 +15,6 @@ import de.neemann.digital.gui.draw.parts.State;
  */
 public class ProbeShape implements Shape {
 
-
     private final String label;
 
     public ProbeShape(String label) {

src/main/java/de/neemann/digital/gui/draw/shapes/Shape.java

@@ -12,6 +12,8 @@ public interface Shape extends Drawable {
 
     /**
      * Puts the pins name and the pins x-y-position together!
+     * This information is used to calculate the models connections
+     * from the wiring in the circuit.
      *
      * @return the pins
      */

src/main/java/de/neemann/digital/gui/draw/shapes/StateMonitor.java

@@ -1,7 +0,0 @@
-package de.neemann.digital.gui.draw.shapes;
-
-/**
- * @author hneemann
- */
-public interface StateMonitor {
-}