Improve constraints and order of packaging

api/src/main/java/com/github/skjolber/packing/api/Box.java

@@ -52,8 +52,13 @@ protected BoxStackValue newStackValue(int dx, int dy, int dz, StackConstraint co
 	protected final long minimumArea;
 	protected final long maximumArea;
 
-	public Box(String id, String name, long volume, int weight, BoxStackValue[] stackValues) {
-		super(id, name);
+	protected final String id;
+	protected final String description;
+
+	public Box(String id, String description, long volume, int weight, BoxStackValue[] stackValues) {
+		this.id = id;
+		this.description = description;
+
 		this.volume = volume;
 		this.weight = weight;
 		this.stackValues = stackValues;
@@ -65,6 +70,16 @@ public Box(String id, String name, long volume, int weight, BoxStackValue[] stac
 			boxStackValue.setStackable(this);
 		}
 	}
+
+	@Override
+	public String getDescription() {
+		return description;
+	}
+
+	@Override
+	public String getId() {
+		return id;
+	}
 
 	@Override
 	public int getWeight() {
@@ -88,6 +103,10 @@ public Box clone() {
 		}
 		return new Box(id, description, volume, weight, stackValues);
 	}
+
+	public StackValue getStackValue(int index) {
+		return stackValues[index];
+	}
 
 	@Override
 	public long getMinimumArea() {

api/src/main/java/com/github/skjolber/packing/api/Container.java

@@ -147,9 +147,13 @@ protected ContainerStackValue[] getStackValues() {
 	protected final long minArea;
 	protected final long maxArea;
 
-	public Container(String id, String name, long volume, int emptyWeight, long maxLoadVolume, int maxLoadWeight, long minArea, long maxArea) {
-		super(id, name);
+	protected final String id;
+	protected final String description;
 
+	public Container(String id, String description, long volume, int emptyWeight, long maxLoadVolume, int maxLoadWeight, long minArea, long maxArea) {
+		this.id = id;
+		this.description = description;
+
 		this.emptyWeight = emptyWeight;
 		this.maxLoadVolume = maxLoadVolume;
 		this.maxLoadWeight = maxLoadWeight;
@@ -159,6 +163,16 @@ public Container(String id, String name, long volume, int emptyWeight, long maxL
 		this.maxArea = maxArea;
 	}
 
+	@Override
+	public String getDescription() {
+		return description;
+	}
+
+	@Override
+	public String getId() {
+		return id;
+	}
+
 	@Override
 	public int getWeight() {
 		return emptyWeight + getStack().getWeight();

api/src/main/java/com/github/skjolber/packing/api/ContainerConstraint.java

@@ -0,0 +1,15 @@
+package com.github.skjolber.packing.api;
+
+import com.github.skjolber.packing.api.packager.StackableItemsFilterBuilder;
+
+/**
+ * 
+ * Interface for handling which Stackables, or combinations of Stackables go into a Container.
+ * 
+ */
+
+public interface ContainerConstraint {
+
+	StackableItemsFilterBuilder<?> newLoadableFilterBuilder();
+
+}

api/src/main/java/com/github/skjolber/packing/api/DefaultContainer.java

@@ -29,6 +29,10 @@ public ContainerStackValue[] getStackValues() {
 	public Stack getStack() {
 		return stack;
 	}
+
+	public ContainerStackValue getStackValue(int index) {
+		return stackValues[index];
+	}
 
 	@Override
 	public DefaultContainer clone() {

api/src/main/java/com/github/skjolber/packing/api/GravitySupport.java

@@ -0,0 +1,7 @@
+package com.github.skjolber.packing.api;
+
+public interface GravitySupport {
+
+	void loaded(StackPlacement stackPlacement);
+
+}

api/src/main/java/com/github/skjolber/packing/api/GravitySupportBuilder.java

@@ -0,0 +1,37 @@
+package com.github.skjolber.packing.api;
+
+/**
+ * Builder scaffold.
+ * 
+ * @see <a href=
+ *      "https://www.sitepoint.com/self-types-with-javas-generics/">https://www.sitepoint.com/self-types-with-javas-generics/</a>
+ */
+
+@SuppressWarnings("unchecked")
+public abstract class GravitySupportBuilder<B extends GravitySupportBuilder<B>> {
+
+	protected Container container;
+	protected ContainerStackValue stackValue;
+	protected Stack stack;
+	protected StackPlacement stackPlacement;
+
+	public B withContainer(Container container) {
+		this.container = container;
+		return (B)this;
+	}
+
+	public B withStack(Stack stack) {
+		this.stack = stack;
+		return (B)this;
+	}
+
+	public B withStackValue(ContainerStackValue stackValue) {
+		this.stackValue = stackValue;
+		return (B)this;
+	}
+
+	public abstract GravitySupport build();
+
+
+
+}

api/src/main/java/com/github/skjolber/packing/api/PlacementSupportBuilder.java

@@ -0,0 +1,36 @@
+package com.github.skjolber.packing.api;
+
+/**
+ * Builder scaffold.
+ * 
+ * @see <a href=
+ *      "https://www.sitepoint.com/self-types-with-javas-generics/">https://www.sitepoint.com/self-types-with-javas-generics/</a>
+ */
+
+@SuppressWarnings("unchecked")
+public abstract class PlacementSupportBuilder<B extends PlacementSupportBuilder<B>> {
+
+	protected Container container;
+	protected ContainerStackValue stackValue;
+	protected Stack stack;
+
+	public B withContainer(Container container) {
+		this.container = container;
+		return (B)this;
+	}
+
+	public B withStack(Stack stack) {
+		this.stack = stack;
+		return (B)this;
+	}
+
+	public B withStackValue(ContainerStackValue stackValue) {
+		this.stackValue = stackValue;
+		return (B)this;
+	}
+
+	public abstract GravitySupport build();
+
+
+
+}

api/src/main/java/com/github/skjolber/packing/api/StackValueConstraint.java

@@ -0,0 +1,8 @@
+package com.github.skjolber.packing.api;
+
+public interface StackValueConstraint {
+
+	GravitySupportBuilder<?> newGravitySupportBuilder();
+
+
+}

api/src/main/java/com/github/skjolber/packing/api/Stackable.java

@@ -8,28 +8,15 @@ public abstract class Stackable implements Serializable {
 
 	private static final long serialVersionUID = 1L;
 
-	protected final String id;
-	protected final String description;
-
-	public Stackable(String id, String description) {
-		super();
-		this.id = id;
-		this.description = description;
-	}
-
 	public abstract long getVolume();
 
 	public abstract int getWeight();
 
 	public abstract StackValue[] getStackValues();
 
-	public String getDescription() {
-		return description;
-	}
+	public abstract String getDescription();
 
-	public String getId() {
-		return id;
-	}
+	public abstract String getId();
 
 	public List<StackValue> fitsInside(Dimension bound) {
 		List<StackValue> list = new ArrayList<>();
@@ -42,6 +29,8 @@ public List<StackValue> fitsInside(Dimension bound) {
 
 		return list;
 	}
+
+	public abstract StackValue getStackValue(int index);
 
 	@Override
 	public abstract Stackable clone();

api/src/main/java/com/github/skjolber/packing/api/StackableItem.java

@@ -11,8 +11,8 @@ public class StackableItem implements Serializable {
 
 	private static final long serialVersionUID = 1L;
 
-	private final int count;
-	private final Stackable stackable;
+	protected int count;
+	protected final Stackable stackable;
 
 	public StackableItem(Stackable box) {
 		this(box, 1);
@@ -36,5 +36,21 @@ public Stackable getStackable() {
 	public String toString() {
 		return String.format("%dx%s", count, stackable);
 	}
+
+	public void decrement() {
+		count--;
+	}
+
+	public boolean isEmpty() {
+		return count == 0;
+	}
+
+	public void decrement(int value) {
+		this.count = this.count - value;
+	}
+
+	public StackableItem clone() {
+		return new StackableItem(stackable, count);
+	}
 
 }

api/src/main/java/com/github/skjolber/packing/api/StackableItemGroup.java

@@ -0,0 +1,88 @@
+package com.github.skjolber.packing.api;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * 
+ * Items which belong together, for example different parts of a single product or order.
+ * 
+ */
+
+public class StackableItemGroup {
+
+	private String id;
+
+	private List<StackableItem> items;
+
+	public StackableItemGroup(String id, List<StackableItem> items) {
+		super();
+		this.id = id;
+		this.items = items;
+	}
+
+	public String getId() {
+		return id;
+	}
+
+	public List<StackableItem> getItems() {
+		return items;
+	}
+
+	public void setId(String id) {
+		this.id = id;
+	}
+
+	public void setItems(List<StackableItem> items) {
+		this.items = items;
+	}
+
+	public int size() {
+		return items.size();
+	}
+
+	public StackableItem get(int i) {
+		return items.get(i);
+	}
+
+
+	public int stackableItemsCount() {
+		int count = 0;
+		for (StackableItem loadableItem : items) {
+			count += loadableItem.getCount();
+		}
+		return count;
+	}
+
+	public boolean isEmpty() {
+		for (StackableItem loadableItem : items) {
+			if(!loadableItem.isEmpty()) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	public void removeEmpty() {
+		for (int j = 0; j < items.size(); j++) {
+			StackableItem loadableItem = items.get(j);
+
+			if(loadableItem.isEmpty()) {
+				items.remove(j);
+				j--;
+			}
+		}
+	}
+
+	public StackableItemGroup clone() {
+		List<StackableItem> items = new ArrayList<>();
+
+		for (StackableItem stackableItem : this.items) {
+			items.add(stackableItem.clone());
+		}
+
+		return new StackableItemGroup(id, items);
+	}
+
+}

api/src/main/java/com/github/skjolber/packing/api/ep/Point3DFilter.java

@@ -0,0 +1,15 @@
+package com.github.skjolber.packing.api.ep;
+import java.util.List;
+
+import com.github.skjolber.packing.api.ep.Point3D;
+
+/**
+ * Constraint describing where a box can be placed within a stack. 
+ * For example, a flammable item must be stacked by the door.
+ */
+
+public interface Point3DFilter {
+
+	List<Point3D> filter(List<Point3D> points);
+
+}