fixed some checkstyle issues

src/main/java/de/neemann/digital/draw/elements/ElementOrder.java

@@ -3,7 +3,6 @@ package de.neemann.digital.draw.elements;
 import de.neemann.digital.core.element.ElementTypeDescription;
 import de.neemann.digital.gui.components.CircuitComponent;
 import de.neemann.digital.gui.components.ElementOrderer;
-import de.neemann.digital.gui.components.modification.Modification;
 
 import java.util.ArrayList;
 

src/main/java/de/neemann/digital/gui/components/modification/Modification.java

@@ -3,10 +3,16 @@ package de.neemann.digital.gui.components.modification;
 import de.neemann.digital.draw.elements.Circuit;
 
 /**
+ * Interface to implement the events used to be reverted
  * Created by hneemann on 25.05.17.
  */
 public interface Modification {
 
+    /**
+     * Performes a modification on the given circuit
+     *
+     * @param circuit the circuit to modify
+     */
     void modify(Circuit circuit);
 
 }

src/main/java/de/neemann/digital/gui/components/modification/ModificationOfVisualElement.java

@@ -5,6 +5,8 @@ import de.neemann.digital.draw.elements.VisualElement;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * A modification on a visual element.
+ * The element is identified by its position and name.
  * Created by hneemann on 25.05.17.
  */
 public abstract class ModificationOfVisualElement implements Modification {
@@ -12,15 +14,32 @@ public abstract class ModificationOfVisualElement implements Modification {
     private final Vector pos;
     private final String name;
 
+    /**
+     * Creates a new instance
+     *
+     * @param ve the element to modify
+     */
     public ModificationOfVisualElement(VisualElement ve) {
         this(ve, ve.getPos());
     }
 
+    /**
+     * Creates a new instance
+     *
+     * @param ve         the element to modify
+     * @param initialPos the initial position of the element
+     */
     public ModificationOfVisualElement(VisualElement ve, Vector initialPos) {
         name = ve.getElementName();
         pos = initialPos;
     }
 
+    /**
+     * Returns the element which is to modify
+     *
+     * @param circuit the circuit
+     * @return the element to modify
+     */
     public VisualElement getVisualElement(Circuit circuit) {
         for (VisualElement ve : circuit.getElements()) {
             if (ve.getPos().equals(pos) && ve.getElementName().equals(name))

src/main/java/de/neemann/digital/gui/components/modification/ModificationOfWire.java

@@ -5,6 +5,8 @@ import de.neemann.digital.draw.elements.Wire;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * A modification on a wire
+ * The wire is identified by its position.
  * Created by hneemann on 25.05.17.
  */
 public abstract class ModificationOfWire implements Modification {
@@ -12,15 +14,32 @@ public abstract class ModificationOfWire implements Modification {
     private final Vector p1;
     private final Vector p2;
 
+    /**
+     * Creates a new instance
+     *
+     * @param wire the wire to modify
+     */
     public ModificationOfWire(Wire wire) {
         this(wire, wire.p1);
     }
 
+    /**
+     * Creates a new instance
+     *
+     * @param wire       the wire to modify
+     * @param initialPos the initial position of the wire
+     */
     public ModificationOfWire(Wire wire, Vector initialPos) {
         p1 = initialPos;
         p2 = initialPos.add(wire.p2.sub(wire.p1));
     }
 
+    /**
+     * Returns the wire to modify
+     *
+     * @param circuit the circuit to modify
+     * @return the wire to modify
+     */
     public Wire getWire(Circuit circuit) {
         for (Wire w : circuit.getWires()) {
             if (w.p1.equals(p1) && w.p2.equals(p2))

src/main/java/de/neemann/digital/gui/components/modification/Modifications.java

@@ -5,6 +5,7 @@ import de.neemann.digital.draw.elements.Circuit;
 import java.util.ArrayList;
 
 /**
+ * A single modification which is build from a set of other modifications.
  * Created by hneemann on 25.05.17.
  */
 public final class Modifications implements Modification {
@@ -20,18 +21,35 @@ public final class Modifications implements Modification {
             m.modify(circuit);
     }
 
+    /**
+     * The builder to construct an instance
+     */
     public static final class Builder {
         private final ArrayList<Modification> list;
 
+        /**
+         * Creates a new instance
+         */
         public Builder() {
             list = new ArrayList<>();
         }
 
+        /**
+         * Adds a modification to this set
+         *
+         * @param m the modification to add
+         * @return this for chained calls
+         */
         public Builder add(Modification m) {
             list.add(m);
             return this;
         }
 
+        /**
+         * Builds the unified of modification
+         *
+         * @return the unified modification
+         */
         public Modification build() {
             return new Modifications(list);
         }

src/main/java/de/neemann/digital/gui/components/modification/ModifyAttribute.java

@@ -5,13 +5,23 @@ import de.neemann.digital.draw.elements.Circuit;
 import de.neemann.digital.draw.elements.VisualElement;
 
 /**
+ * Modifies an attribute.
  * Created by hneemann on 25.05.17.
+ *
+ * @param <VALUE> the used value type
  */
 public class ModifyAttribute<VALUE> extends ModificationOfVisualElement {
 
     private final Key<VALUE> key;
     private final VALUE value;
 
+    /**
+     * Creates a new instance
+     *
+     * @param ve    the visual element to modify
+     * @param key   the key to modify
+     * @param value the new value
+     */
     public ModifyAttribute(VisualElement ve, Key<VALUE> key, VALUE value) {
         super(ve);
         this.key = key;

src/main/java/de/neemann/digital/gui/components/modification/ModifyAttributes.java

@@ -5,12 +5,18 @@ import de.neemann.digital.draw.elements.Circuit;
 import de.neemann.digital.draw.elements.VisualElement;
 
 /**
+ * Sets all attributes of an element
  * Created by hneemann on 25.05.17.
  */
 public class ModifyAttributes extends ModificationOfVisualElement {
 
     private final ElementAttributes attributes;
 
+    /**
+     * Creates a new instance
+     *
+     * @param ve the already modified element
+     */
     public ModifyAttributes(VisualElement ve) {
         super(ve);
         attributes = new ElementAttributes(ve.getElementAttributes());

src/main/java/de/neemann/digital/gui/components/modification/ModifyDeleteElement.java

@@ -5,9 +5,17 @@ import de.neemann.digital.draw.elements.VisualElement;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * Modifier which deletes an element
  * Created by hneemann on 26.05.17.
  */
 public class ModifyDeleteElement extends ModificationOfVisualElement {
+
+    /**
+     * The element to delete
+     *
+     * @param ve         the visual element
+     * @param initialPos its initial position
+     */
     public ModifyDeleteElement(VisualElement ve, Vector initialPos) {
         super(ve, initialPos);
     }

src/main/java/de/neemann/digital/gui/components/modification/ModifyDeleteRect.java

@@ -4,12 +4,19 @@ import de.neemann.digital.draw.elements.Circuit;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * Modifier to delete all elements in a given rectangle
  * Created by hneemann on 26.05.17.
  */
 public class ModifyDeleteRect implements Modification {
     private final Vector min;
     private final Vector max;
 
+    /**
+     * Creates a new instance
+     *
+     * @param min the upper left corner
+     * @param max the lower right corner
+     */
     public ModifyDeleteRect(Vector min, Vector max) {
         this.min = min;
         this.max = max;

src/main/java/de/neemann/digital/gui/components/modification/ModifyDeleteWire.java

@@ -5,10 +5,17 @@ import de.neemann.digital.draw.elements.Wire;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * Modifier to delete a wire
  * Created by hneemann on 26.05.17.
  */
 public class ModifyDeleteWire extends ModificationOfWire {
 
+    /**
+     * Creates a new instance
+     *
+     * @param wire       the wire to delete
+     * @param initialPos its initial position
+     */
     public ModifyDeleteWire(Wire wire, Vector initialPos) {
         super(wire, initialPos);
     }

src/main/java/de/neemann/digital/gui/components/modification/ModifyInsertElement.java

@@ -4,11 +4,17 @@ import de.neemann.digital.draw.elements.Circuit;
 import de.neemann.digital.draw.elements.VisualElement;
 
 /**
+ * Modifier to insert an element
  * Created by hneemann on 26.05.17.
  */
 public class ModifyInsertElement implements Modification {
     private final VisualElement element;
 
+    /**
+     * Creates a new instance
+     *
+     * @param element the element to insert
+     */
     public ModifyInsertElement(VisualElement element) {
         this.element = new VisualElement(element);
     }

src/main/java/de/neemann/digital/gui/components/modification/ModifyInsertWire.java

@@ -5,12 +5,18 @@ import de.neemann.digital.draw.elements.Wire;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * Modifier to insert a wire.
  * Created by hneemann on 26.05.17.
  */
 public class ModifyInsertWire implements Modification {
     private final Vector p1;
     private final Vector p2;
 
+    /**
+     * Creates a new instance
+     *
+     * @param w the wire to insert
+     */
     public ModifyInsertWire(Wire w) {
         p1 = w.p1;
         p2 = w.p2;

src/main/java/de/neemann/digital/gui/components/modification/ModifyMoveAndRotElement.java

@@ -5,12 +5,19 @@ import de.neemann.digital.draw.elements.VisualElement;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * Modifier to move and rotate a single visual element
  * Created by hneemann on 26.05.17.
  */
 public class ModifyMoveAndRotElement extends ModificationOfVisualElement {
     private final Vector pos;
     private final int rotation;
 
+    /**
+     * Create a new instance
+     *
+     * @param ve         the visual Element
+     * @param initialPos its initial position
+     */
     public ModifyMoveAndRotElement(VisualElement ve, Vector initialPos) {
         super(ve, initialPos);
         pos = ve.getPos();

src/main/java/de/neemann/digital/gui/components/modification/ModifyMoveSelected.java

@@ -11,6 +11,7 @@ import de.neemann.digital.draw.graphics.Vector;
 import java.util.ArrayList;
 
 /**
+ * Modifier to move a selection
  * Created by hneemann on 26.05.17.
  */
 public class ModifyMoveSelected implements Modification {
@@ -20,6 +21,15 @@ public class ModifyMoveSelected implements Modification {
     private final int accumulatedRotate;
     private final Vector center;
 
+    /**
+     * Create a new instance
+     *
+     * @param min               the upper left corner
+     * @param max               the lower right corner
+     * @param accumulatedDelta  the translation
+     * @param accumulatedRotate the rotation
+     * @param center            the center of the selection rectangle
+     */
     public ModifyMoveSelected(Vector min, Vector max, Vector accumulatedDelta, int accumulatedRotate, Vector center) {
         this.min = min;
         this.max = max;
@@ -40,6 +50,12 @@ public class ModifyMoveSelected implements Modification {
         circuit.elementsMoved();
     }
 
+    /**
+     * Rotates the given elements
+     *
+     * @param elements the elements to rotate
+     * @param center   the center position
+     */
     public static void rotateElements(ArrayList<Movable> elements, Vector center) {
         Transform transform = new TransformRotate(center, 1) {
             @Override

src/main/java/de/neemann/digital/gui/components/modification/ModifyMoveWire.java

@@ -5,11 +5,18 @@ import de.neemann.digital.draw.elements.Wire;
 import de.neemann.digital.draw.graphics.Vector;
 
 /**
+ * Modifier to move a wire
  * Created by hneemann on 26.05.17.
  */
 public class ModifyMoveWire extends ModificationOfWire {
     private final Vector delta;
 
+    /**
+     * Create a new instance
+     *
+     * @param wire       the wire to modify
+     * @param initialPos its initial position
+     */
     public ModifyMoveWire(Wire wire, Vector initialPos) {
         super(wire, initialPos);
         delta = wire.getPos().sub(initialPos);