Implemented rudimentary auto-positioning feature using alphabetic sorting of relations

Now going to be working on custom sorting

src/main/java/nl/andrewlalis/erme/control/actions/AutoPositionAction.java

@@ -0,0 +1,56 @@
+package nl.andrewlalis.erme.control.actions;
+
+import lombok.Getter;
+import lombok.Setter;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+import nl.andrewlalis.erme.view.DiagramPanel;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class AutoPositionAction extends AbstractAction {
+	private static AutoPositionAction instance;
+	private final static int MARGIN = 10;
+	private final static int PADDING = 10;
+
+	public static AutoPositionAction getInstance() {
+		if (instance == null) {
+			instance = new AutoPositionAction();
+		}
+		return instance;
+	}
+
+	@Setter
+	private DiagramPanel diagramPanel;
+	@Setter
+	private MappingModel model;
+
+	public AutoPositionAction() {
+		super("Position Relations");
+		this.putValue(SHORT_DESCRIPTION, "Automatically Position Relations");
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent actionEvent) {
+		this.positionRelations();
+		diagramPanel.repaint();
+	}
+
+	private void positionRelations() {
+		diagramPanel.resetTranslation();
+		ArrayList<Relation> relationList = new ArrayList<>(model.getRelations());
+		Collections.sort(relationList);
+		if (relationList.isEmpty()) return;
+
+		int vertSpace = (int) relationList.get(0).getViewModel().getBounds(diagramPanel.getGraphics2D()).getHeight() + PADDING;
+		AtomicInteger vertPos = new AtomicInteger(MARGIN);
+		relationList.forEach(r -> {
+			r.setPosition(new Point(MARGIN, vertPos.getAndAdd(vertSpace)));
+		});
+	}
+}

src/main/java/nl/andrewlalis/erme/model/Relation.java

@@ -15,7 +15,7 @@ import java.util.stream.Collectors;
  * Represents a single "relation" or table in the diagram.
  */
 @Getter
-public class Relation implements Serializable, Viewable {
+public class Relation implements Serializable, Viewable, Comparable<Relation> {
 	private final MappingModel model;
 	private Point position;
 	private String name;
@@ -97,4 +97,9 @@ public class Relation implements Serializable, Viewable {
 		this.getAttributes().forEach(a -> c.addAttribute(a.copy(c)));
 		return c;
 	}
+
+	@Override
+	public int compareTo(Relation relation) {
+		return this.name.compareTo(relation.name);
+	}
 }

src/main/java/nl/andrewlalis/erme/view/DiagramPanel.java

@@ -129,6 +129,8 @@ public class DiagramPanel extends JPanel implements ModelChangeListener {
 		RemoveAttributeAction.getInstance().setModel(this.model);
 		LoadSampleModelAction.getInstance().setDiagramPanel(this);
 		LolcatAction.getInstance().setDiagramPanel(this);
+		AutoPositionAction.getInstance().setDiagramPanel(this);
+		AutoPositionAction.getInstance().setModel(this.model);
 	}
 
 	public static void prepareGraphics(Graphics2D g) {

src/main/java/nl/andrewlalis/erme/view/EditorMenuBar.java

@@ -40,6 +40,7 @@ public class EditorMenuBar extends JMenuBar {
 		menu.add(AddAttributeAction.getInstance());
 		menu.add(RemoveAttributeAction.getInstance());
 		menu.add(new JCheckBoxMenuItem(LolcatAction.getInstance()));
+		menu.add(AutoPositionAction.getInstance());
 		menu.addSeparator();
 		menu.add(UndoAction.getInstance());
 		menu.add(RedoAction.getInstance());

src/main/java/nl/andrewlalis/erme/view/OrderableListModel.java

@@ -0,0 +1,16 @@
+package nl.andrewlalis.erme.view;
+
+import nl.andrewlalis.erme.model.Relation;
+
+import java.util.ArrayList;
+import java.util.Collections;
+
+public class OrderableListModel {
+    private ArrayList<Relation> list;
+
+    public void moveUp(int index) {
+        if (index > 0) {
+            Collections.swap(list, index, index - 1);
+        }
+    }
+}