Removed useless admin stuff, changed to save files as JSON, added image scaling for exports.

README.md

@@ -1,6 +1,11 @@
 # Entity-Relation Mapping Editor
 A simple UI for editing entity-relation mapping diagrams.
 
+## Usage
+This program is distributed as an executable **jar** file. You can find the latest release [here](https://github.com/andrewlalis/EntityRelationMappingEditor/releases). You will need Java installed on your computer (version 8 or higher). [You can install an OpenJDK version of Java here.](https://adoptium.net/)
+
+Simply double-click on the jar file, or execute `java -jar <jar file>` from the command line (where `<jar file>` is replaced with the path to your actual jar file).
+
 ![window screenshot](https://raw.githubusercontent.com/andrewlalis/EntityRelationMappingEditor/main/design/main_interface.PNG)
 
 ## How to Use

pom.xml

@@ -6,7 +6,7 @@
 
     <groupId>nl.andrewlalis</groupId>
     <artifactId>EntityRelationMappingEditor</artifactId>
-    <version>1.5.0</version>
+    <version>1.6.0</version>
     <build>
         <plugins>
             <plugin>
@@ -50,13 +50,19 @@
         <dependency>
             <groupId>com.formdev</groupId>
             <artifactId>flatlaf</artifactId>
-            <version>1.0-rc3</version>
+            <version>1.6.1</version>
         </dependency>
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
-            <version>1.18.16</version>
+            <version>1.18.22</version>
             <scope>provided</scope>
         </dependency>
+        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.13.0</version>
+        </dependency>
     </dependencies>
 </project>

src/main/java/nl/andrewlalis/erme/EntityRelationMappingEditor.java

@@ -1,31 +1,16 @@
 package nl.andrewlalis.erme;
 
 import com.formdev.flatlaf.FlatLightLaf;
-import nl.andrewlalis.erme.util.Hash;
 import nl.andrewlalis.erme.view.EditorFrame;
 
-import java.nio.charset.StandardCharsets;
-
 public class EntityRelationMappingEditor {
-	public static final String VERSION = "1.5.0";
+	public static final String VERSION = "1.6.0";
 
 	public static void main(String[] args) {
-		if (!FlatLightLaf.install()) {
+		if (!FlatLightLaf.setup()) {
 			System.err.println("Could not install FlatLight Look and Feel.");
 		}
-		final boolean includeAdminActions = shouldIncludeAdminActions(args);
+		EditorFrame frame = new EditorFrame();
-		if (includeAdminActions) {
-			System.out.println("Admin actions have been enabled.");
-		}
-		EditorFrame frame = new EditorFrame(includeAdminActions);
 		frame.setVisible(true);
 	}
-
-	private static boolean shouldIncludeAdminActions(String[] args) {
-		if (args.length < 1) {
-			return false;
-		}
-		byte[] pw = args[0].getBytes(StandardCharsets.UTF_8);
-		return Hash.matches(pw, "admin_hash.txt");
-	}
 }

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

@@ -4,7 +4,6 @@ import lombok.Setter;
 import nl.andrewlalis.erme.model.MappingModel;
 import nl.andrewlalis.erme.model.Relation;
 import nl.andrewlalis.erme.view.DiagramPanel;
-import nl.andrewlalis.erme.view.view_models.AttributeViewModel;
 import nl.andrewlalis.erme.view.view_models.MappingModelViewModel;
 
 import javax.imageio.ImageIO;
@@ -77,9 +76,18 @@ public class ExportToImageAction extends AbstractAction {
 			} else {
 				chosenFile = new File(chosenFile.getParent(), chosenFile.getName() + '.' + extension);
 			}
+			String input = JOptionPane.showInputDialog(this.diagramPanel, "Choose a scale for the image.", "3.0");
+			float scale;
+			try {
+				scale = Float.parseFloat(input);
+				if (scale <= 0.0f || scale > 64.0f) throw new IllegalArgumentException();
+			} catch (Exception ex) {
+				JOptionPane.showMessageDialog(this.diagramPanel, "Invalid scale value. Should be a positive number less than 64.", "Invalid Scale", JOptionPane.WARNING_MESSAGE);
+				return;
+			}
 			try {
 				long start = System.currentTimeMillis();
-				BufferedImage render = this.renderModel();
+				BufferedImage render = this.renderModel(scale);
 				double durationSeconds = (System.currentTimeMillis() - start) / 1000.0;
 				ImageIO.write(render, extension, chosenFile);
 				prefs.put(LAST_EXPORT_LOCATION_KEY, chosenFile.getAbsolutePath());
@@ -97,12 +105,19 @@ public class ExportToImageAction extends AbstractAction {
 		}
 	}
 
-	private BufferedImage renderModel() {
+	/**
+	 * Renders the mapping model to an image with the given resolution.
+	 * @param scale The scale to use. Should be greater than zero.
+	 * @return The image which was rendered.
+	 */
+	private BufferedImage renderModel(float scale) {
 		// Prepare a tiny sample image that we can use to determine the bounds of the model in a graphics context.
 		BufferedImage bufferedImage = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
 		Graphics2D g2d = bufferedImage.createGraphics();
 		DiagramPanel.prepareGraphics(g2d);
 		final Rectangle bounds = this.model.getViewModel().getBounds(g2d);
+		bounds.width *= scale;
+		bounds.height *= scale;
 
 		// Prepare the output image.
 		BufferedImage outputImage = new BufferedImage(bounds.width, bounds.height + 20, BufferedImage.TYPE_INT_RGB);
@@ -112,7 +127,10 @@ public class ExportToImageAction extends AbstractAction {
 
 		// Transform the graphics space to account for the model's offset from origin.
 		AffineTransform originalTransform = g2d.getTransform();
-		g2d.setTransform(AffineTransform.getTranslateInstance(-bounds.x, -bounds.y));
+		AffineTransform modelTransform = new AffineTransform();
+		modelTransform.scale(scale, scale);
+		modelTransform.translate(-bounds.x, -bounds.y);
+		g2d.setTransform(modelTransform);
 		DiagramPanel.prepareGraphics(g2d);
 
 		// Render the model.
@@ -124,9 +142,9 @@ public class ExportToImageAction extends AbstractAction {
 		this.model.getRelations().forEach(r -> r.setSelected(selectedRelations.contains(r)));
 		LolcatAction.getInstance().setLolcatEnabled(lolcat); // revert previous lolcat mode
 
-		// Revert back to the normal image space, and render a watermark.
+		// Revert to the normal image space, and render a watermark.
 		g2d.setTransform(originalTransform);
-		g2d.setColor(Color.LIGHT_GRAY);
+		g2d.setColor(Color.decode("#e8e8e8"));
 		g2d.setFont(g2d.getFont().deriveFont(10.0f));
 		g2d.drawString("Created by EntityRelationMappingEditor", 0, outputImage.getHeight() - 3);
 		return outputImage;

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

@@ -13,6 +13,9 @@ import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.URISyntaxException;
 
+/**
+ * An action which, when performed, opens a view that displays an HTML document.
+ */
 public abstract class HtmlDocumentViewerAction extends AbstractAction {
 	private final String resourceFileName;
 	private final Dialog.ModalityType modalityType;

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

@@ -1,19 +1,22 @@
 package nl.andrewlalis.erme.control.actions;
 
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import lombok.Setter;
 import nl.andrewlalis.erme.model.MappingModel;
 import nl.andrewlalis.erme.view.DiagramPanel;
 
 import javax.swing.*;
 import javax.swing.filechooser.FileNameExtensionFilter;
-import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.InputEvent;
 import java.awt.event.KeyEvent;
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.IOException;
-import java.io.ObjectInputStream;
 import java.util.prefs.Preferences;
 
 public class LoadAction extends AbstractAction {
@@ -40,8 +43,8 @@ public class LoadAction extends AbstractAction {
 	public void actionPerformed(ActionEvent e) {
 		JFileChooser fileChooser = new JFileChooser();
 		FileNameExtensionFilter filter = new FileNameExtensionFilter(
-				"ERME Serialized Files",
+				"JSON Files",
-				"erme"
+				"json"
 		);
 		fileChooser.setFileFilter(filter);
 		Preferences prefs = Preferences.userNodeForPackage(LoadAction.class);
@@ -56,11 +59,15 @@ public class LoadAction extends AbstractAction {
 				JOptionPane.showMessageDialog(fileChooser, "The selected file cannot be read.", "Invalid File", JOptionPane.WARNING_MESSAGE);
 				return;
 			}
-			try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(chosenFile))) {
+			try (FileInputStream fis = new FileInputStream(chosenFile)) {
-				MappingModel loadedModel = (MappingModel) ois.readObject();
+				ObjectMapper mapper = JsonMapper.builder()
-				this.diagramPanel.setModel(loadedModel);
+						.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
+						.configure(MapperFeature.PROPAGATE_TRANSIENT_MARKER, true)
+						.build();
+				JsonNode data = mapper.readValue(fis, JsonNode.class);
+				this.diagramPanel.setModel(MappingModel.fromJson((ObjectNode) data));
 				prefs.put(LAST_LOAD_LOCATION_KEY, chosenFile.getAbsolutePath());
-			} catch (IOException | ClassNotFoundException | ClassCastException ex) {
+			} catch (Exception ex) {
 				ex.printStackTrace();
 				JOptionPane.showMessageDialog(fileChooser, "An error occurred and the file could not be read:\n" + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
 			}

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

@@ -1,19 +1,21 @@
 package nl.andrewlalis.erme.control.actions;
 
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import com.fasterxml.jackson.databind.json.JsonMapper;
 import lombok.Setter;
 import nl.andrewlalis.erme.model.MappingModel;
 import nl.andrewlalis.erme.view.DiagramPanel;
 
 import javax.swing.*;
 import javax.swing.filechooser.FileNameExtensionFilter;
-import java.awt.*;
 import java.awt.event.ActionEvent;
 import java.awt.event.InputEvent;
 import java.awt.event.KeyEvent;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.ObjectOutputStream;
 import java.util.prefs.Preferences;
 
 public class SaveAction extends AbstractAction {
@@ -29,6 +31,7 @@ public class SaveAction extends AbstractAction {
 
 	@Setter
 	private MappingModel model;
+
 	@Setter
 	private DiagramPanel diagramPanel;
 
@@ -42,8 +45,8 @@ public class SaveAction extends AbstractAction {
 	public void actionPerformed(ActionEvent e) {
 		JFileChooser fileChooser = new JFileChooser();
 		FileNameExtensionFilter filter = new FileNameExtensionFilter(
-				"ERME Serialized Files",
+				"JSON Files",
-				"erme"
+				"json"
 		);
 		fileChooser.setFileFilter(filter);
 		Preferences prefs = Preferences.userNodeForPackage(SaveAction.class);
@@ -55,15 +58,23 @@ public class SaveAction extends AbstractAction {
 		if (choice == JFileChooser.APPROVE_OPTION) {
 			File chosenFile = fileChooser.getSelectedFile();
 			if (chosenFile == null || chosenFile.isDirectory()) {
-				JOptionPane.showMessageDialog(fileChooser, "The selected file cannot be written to.", "Invalid File", JOptionPane.WARNING_MESSAGE);
+				JOptionPane.showMessageDialog(this.diagramPanel, "The selected file cannot be written to.", "Invalid File", JOptionPane.WARNING_MESSAGE);
 				return;
 			}
-			if (!chosenFile.exists() && !chosenFile.getName().endsWith(".erme")) {
+			if (!chosenFile.exists() && !chosenFile.getName().endsWith(".json")) {
-				chosenFile = new File(chosenFile.getParent(), chosenFile.getName() + ".erme");
+				chosenFile = new File(chosenFile.getParent(), chosenFile.getName() + ".json");
+			} else if (chosenFile.exists()) {
+				int result = JOptionPane.showConfirmDialog(this.diagramPanel, "Are you sure you want overwrite this file?", "Overwrite", JOptionPane.YES_NO_OPTION);
+				if (result == JOptionPane.NO_OPTION) {
+					return;
+				}
 			}
-			// TODO: Check for confirm before overwriting.
+			try (FileOutputStream fos = new FileOutputStream(chosenFile)) {
-			try (ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(chosenFile))) {
+				ObjectMapper mapper = JsonMapper.builder()
-				oos.writeObject(this.model);
+						.configure(SerializationFeature.INDENT_OUTPUT, true)
+						.configure(MapperFeature.PROPAGATE_TRANSIENT_MARKER, true)
+						.build();
+				mapper.writeValue(fos, this.model.toJson(mapper));
 				prefs.put(LAST_SAVE_LOCATION_KEY, chosenFile.getAbsolutePath());
 				JOptionPane.showMessageDialog(fileChooser, "File saved successfully.", "Success", JOptionPane.INFORMATION_MESSAGE);
 			} catch (IOException ex) {

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

@@ -3,14 +3,13 @@ package nl.andrewlalis.erme.model;
 import lombok.Getter;
 import nl.andrewlalis.erme.view.view_models.AttributeViewModel;
 
-import java.io.Serializable;
 import java.util.Objects;
 
 /**
  * A single value that belongs to a relation.
  */
 @Getter
-public class Attribute implements Serializable {
+public class Attribute {
 	private final Relation relation;
 	private AttributeType type;
 	private String name;
@@ -32,7 +31,7 @@ public class Attribute implements Serializable {
 		this.name = name;
 		this.relation.getModel().fireChangedEvent();
 	}
-
+	
 	public AttributeViewModel getViewModel() {
 		if (this.viewModel == null) {
 			this.viewModel = new AttributeViewModel(this);

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

@@ -1,29 +1,27 @@
 package nl.andrewlalis.erme.model;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import lombok.Getter;
-import nl.andrewlalis.erme.view.OrderableListPanel;
 import nl.andrewlalis.erme.view.view_models.MappingModelViewModel;
 import nl.andrewlalis.erme.view.view_models.ViewModel;
 
 import java.awt.*;
-import java.io.Serializable;
-import java.util.HashSet;
 import java.util.List;
-import java.util.Objects;
+import java.util.*;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 /**
  * This model contains all the information about a single mapping diagram,
  * including each mapped table and the links between them.
  */
-public class MappingModel implements Serializable, Viewable {
+public class MappingModel implements Viewable {
 	@Getter
 	private final Set<Relation> relations;
 
-	private transient Set<ModelChangeListener> changeListeners;
+	private transient final Set<ModelChangeListener> changeListeners;
-
-	private final static long serialVersionUID = 6153776381873250304L;
 
 	public MappingModel() {
 		this.relations = new HashSet<>();
@@ -42,10 +40,20 @@ public class MappingModel implements Serializable, Viewable {
 		}
 	}
 
+	/**
+	 * Gets the list of relations which are currently selected.
+	 * @return The list of relations which are selected.
+	 */
 	public List<Relation> getSelectedRelations() {
 		return this.relations.stream().filter(Relation::isSelected).collect(Collectors.toList());
 	}
 
+	/**
+	 * Finds an attribute in this model, or returns null otherwise.
+	 * @param relationName The name of the relation the attribute is in.
+	 * @param attributeName The name of the attribute.
+	 * @return The attribute which was found, or null if none was found.
+	 */
 	public Attribute findAttribute(String relationName, String attributeName) {
 		for (Relation r : this.getRelations()) {
 			if (!r.getName().equals(relationName)) continue;
@@ -58,6 +66,11 @@ public class MappingModel implements Serializable, Viewable {
 		return null;
 	}
 
+	/**
+	 * Removes all attributes from any relation in the model which reference the
+	 * given attribute.
+	 * @param referenced The attribute to remove references from.
+	 */
 	public void removeAllReferencingAttributes(Attribute referenced) {
 		for (Relation r : this.getRelations()) {
 			Set<Attribute> removalSet = new HashSet<>();
@@ -73,6 +86,10 @@ public class MappingModel implements Serializable, Viewable {
 		}
 	}
 
+	/**
+	 * Gets the bounding rectangle around all relations of the model.
+	 * @return The bounding rectangle around all relations in this model.
+	 */
 	public Rectangle getRelationBounds() {
 		if (this.getRelations().isEmpty()) {
 			return new Rectangle(0, 0, 0, 0);
@@ -90,14 +107,20 @@ public class MappingModel implements Serializable, Viewable {
 		return new Rectangle(minX, minY, maxX - minX, maxY - minY);
 	}
 
+	/**
+	 * Adds a listener to this model, which will be notified of changes to the
+	 * model.
+	 * @param listener The listener to add.
+	 */
 	public void addChangeListener(ModelChangeListener listener) {
-		if (this.changeListeners == null) {
-			this.changeListeners = new HashSet<>();
-		}
 		this.changeListeners.add(listener);
 		listener.onModelChanged();
 	}
 
+	/**
+	 * Fires an all-purpose event which notifies all listeners that the model
+	 * has changed.
+	 */
 	public final void fireChangedEvent() {
 		this.changeListeners.forEach(ModelChangeListener::onModelChanged);
 	}
@@ -146,4 +169,106 @@ public class MappingModel implements Serializable, Viewable {
 		this.getRelations().forEach(r -> c.addRelation(r.copy(c)));
 		return c;
 	}
+
+	public ObjectNode toJson(ObjectMapper mapper) {
+		ObjectNode node = mapper.createObjectNode();
+		ArrayNode relationsArray = node.withArray("relations");
+		for (Relation r : this.relations) {
+			ObjectNode relationNode = mapper.createObjectNode()
+					.put("name", r.getName());
+			ObjectNode positionNode = mapper.createObjectNode()
+					.put("x", r.getPosition().x)
+					.put("y", r.getPosition().y);
+			relationNode.set("position", positionNode);
+			ArrayNode attributesArray = relationNode.withArray("attributes");
+			for (Attribute a : r.getAttributes()) {
+				ObjectNode attributeNode = mapper.createObjectNode()
+						.put("name", a.getName())
+						.put("type", a.getType().name());
+				if (a instanceof ForeignKeyAttribute) {
+					ForeignKeyAttribute fk = (ForeignKeyAttribute) a;
+					ObjectNode referenceNode = mapper.createObjectNode()
+							.put("relation", fk.getReference().getRelation().getName())
+							.put("attribute", fk.getReference().getName());
+					attributeNode.set("references", referenceNode);
+				}
+				attributesArray.add(attributeNode);
+			}
+			relationsArray.add(relationNode);
+		}
+		return node;
+	}
+
+	public static MappingModel fromJson(ObjectNode node) {
+		MappingModel model = new MappingModel();
+		for (JsonNode relationNodeRaw : node.withArray("relations")) {
+			if (!relationNodeRaw.isObject()) throw new IllegalArgumentException();
+			ObjectNode relationNode = (ObjectNode) relationNodeRaw;
+			String name = relationNode.get("name").asText();
+			int x = relationNode.get("position").get("x").asInt();
+			int y = relationNode.get("position").get("y").asInt();
+			Point position = new Point(x, y);
+			Relation relation = new Relation(model, position, name);
+			for (JsonNode attributeNodeRaw : relationNode.withArray("attributes")) {
+				if (!attributeNodeRaw.isObject()) throw new IllegalArgumentException();
+				ObjectNode attributeNode = (ObjectNode) attributeNodeRaw;
+				String attributeName = attributeNode.get("name").asText();
+				AttributeType type = AttributeType.valueOf(attributeNode.get("type").asText().toUpperCase());
+				Attribute attribute = new Attribute(relation, type, attributeName);
+				relation.addAttribute(attribute);
+			}
+			model.addRelation(relation);
+		}
+		addForeignKeys(model, node);
+		return model;
+	}
+
+	private static void addForeignKeys(MappingModel model, ObjectNode node) {
+		Map<Attribute, ObjectNode> references = buildReferenceMap(model, node);
+		while (!references.isEmpty()) {
+			boolean workDone = false;
+			for (Map.Entry<Attribute, ObjectNode> entry : references.entrySet()) {
+				Attribute attribute = entry.getKey();
+				String referencedName = entry.getValue().get("attribute").asText();
+				String referencedRelation = entry.getValue().get("relation").asText();
+				Attribute referencedAttribute = model.findAttribute(referencedRelation, referencedName);
+				if (referencedAttribute == null) throw new IllegalArgumentException("Foreign key referenced unknown attribute.");
+				if (!references.containsKey(referencedAttribute)) {
+					ForeignKeyAttribute fk = new ForeignKeyAttribute(attribute.getRelation(), attribute.getType(), attribute.getName(), referencedAttribute);
+					attribute.getRelation().removeAttribute(attribute);
+					attribute.getRelation().addAttribute(fk);
+					references.remove(attribute);
+					workDone = true;
+				}
+			}
+			if (!workDone) {
+				throw new IllegalArgumentException("Invalid foreign key structure. Possible cyclic references.");
+			}
+		}
+	}
+
+	/**
+	 * Builds a map that contains the set of foreign key references, indexed by
+	 * the primitive attribute that is referencing another.
+	 * @param model The model to lookup attributes from.
+	 * @param node The raw JSON data for the model.
+	 * @return A map containing foreign key references, to be used to build a
+	 * complete model with foreign key attributes.
+	 */
+	private static Map<Attribute, ObjectNode> buildReferenceMap(MappingModel model, ObjectNode node) {
+		Map<Attribute, ObjectNode> references = new HashMap<>();
+		for (JsonNode r : node.withArray("relations")) {
+			for (JsonNode a : r.withArray("attributes")) {
+				if (a.has("references") && a.get("references").isObject()) {
+					ObjectNode referenceNode = (ObjectNode) a.get("references");
+					String attributeName = a.get("name").asText();
+					String relationName = r.get("name").asText();
+					Attribute attribute = model.findAttribute(relationName, attributeName);
+					if (attribute == null) throw new IllegalArgumentException("Mapping model is not complete. Missing attribute " + attributeName + " in relation " + relationName + ".");
+					references.put(attribute, referenceNode);
+				}
+			}
+		}
+		return references;
+	}
 }

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

@@ -5,7 +5,6 @@ import nl.andrewlalis.erme.view.view_models.RelationViewModel;
 import nl.andrewlalis.erme.view.view_models.ViewModel;
 
 import java.awt.*;
-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
@@ -15,7 +14,7 @@ import java.util.stream.Collectors;
  * Represents a single "relation" or table in the diagram.
  */
 @Getter
-public class Relation implements Serializable, Viewable, Comparable<Relation> {
+public class Relation implements Viewable, Comparable<Relation> {
 	private final MappingModel model;
 	private Point position;
 	private String name;
@@ -24,11 +23,15 @@ public class Relation implements Serializable, Viewable, Comparable<Relation> {
 	private transient boolean selected;
 	private transient RelationViewModel viewModel;
 
-	public Relation(MappingModel model, Point position, String name) {
+	public Relation(MappingModel model, Point position, String name, List<Attribute> attributes) {
 		this.model = model;
 		this.position = position;
 		this.name = name;
-		this.attributes = new ArrayList<>();
+		this.attributes = attributes;
+	}
+
+	public Relation(MappingModel model, Point position, String name) {
+		this(model, position, name, new ArrayList<>());
 	}
 
 	public void setPosition(Point position) {

src/main/java/nl/andrewlalis/erme/util/Hash.java

@@ -1,50 +0,0 @@
-package nl.andrewlalis.erme.util;
-
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.util.Arrays;
-
-public class Hash {
-	public static boolean matches(byte[] password, String resourceFile) {
-		MessageDigest md;
-		try {
-			md = MessageDigest.getInstance("SHA-256");
-		} catch (NoSuchAlgorithmException e) {
-			e.printStackTrace();
-			return false;
-		}
-		byte[] passwordHash = md.digest(password);
-		InputStream is = Hash.class.getClassLoader().getResourceAsStream(resourceFile);
-		if (is == null) {
-			System.err.println("Could not obtain input stream to admin_hash.txt");
-			return false;
-		}
-		char[] buffer = new char[64];
-		try (BufferedReader br = new BufferedReader(new InputStreamReader(is))) {
-			if (br.read(buffer) != buffer.length) {
-				System.err.println("Incorrect number of characters read from hash file.");
-				return false;
-			}
-		} catch (IOException e) {
-			e.printStackTrace();
-			return false;
-		}
-		String hashHex = String.valueOf(buffer);
-		byte[] hash = hexStringToByteArray(hashHex);
-		return Arrays.equals(passwordHash, hash);
-	}
-
-	private static byte[] hexStringToByteArray(String s) {
-		int len = s.length();
-		byte[] data = new byte[len / 2];
-		for (int i = 0; i < len; i += 2) {
-			data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
-					+ Character.digit(s.charAt(i+1), 16));
-		}
-		return data;
-	}
-}

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

@@ -117,6 +117,7 @@ public class DiagramPanel extends JPanel implements ModelChangeListener {
 
 	/**
 	 * Updates all the action singletons with the latest model information.
+	 * TODO: Clean this up somehow!
 	 */
 	private void updateActionModels() {
 		NewModelAction.getInstance().setDiagramPanel(this);
@@ -134,10 +135,10 @@ public class DiagramPanel extends JPanel implements ModelChangeListener {
 		RemoveAttributeAction.getInstance().setDiagramPanel(this);
 		LoadSampleModelAction.getInstance().setDiagramPanel(this);
 		LolcatAction.getInstance().setDiagramPanel(this);
-    AutoPositionAction.getInstance().setDiagramPanel(this);
+    	AutoPositionAction.getInstance().setDiagramPanel(this);
 		AutoPositionAction.getInstance().setModel(this.model);
 		OrderableListPanel.getInstance().setModel(this.model);
-    AboutAction.getInstance().setDiagramPanel(this);
+    	AboutAction.getInstance().setDiagramPanel(this);
 		ExitAction.getInstance().setDiagramPanel(this);
 		InstructionsAction.getInstance().setDiagramPanel(this);
 		MappingAlgorithmHelpAction.getInstance().setDiagramPanel(this);

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

@@ -2,17 +2,30 @@ package nl.andrewlalis.erme.view;
 
 import nl.andrewlalis.erme.model.MappingModel;
 
+import javax.imageio.ImageIO;
 import javax.swing.*;
 import java.awt.*;
+import java.io.IOException;
+import java.io.InputStream;
 
 /**
  * The main JFrame for the editor.
  */
 public class EditorFrame extends JFrame {
-	public EditorFrame(boolean includeAdminActions) {
+	public EditorFrame() {
 		super("ER-Mapping Editor");
 		this.setContentPane(new DiagramPanel(new MappingModel()));
-		this.setJMenuBar(new EditorMenuBar(includeAdminActions));
+		this.setJMenuBar(new EditorMenuBar());
+		try {
+			InputStream is = getClass().getClassLoader().getResourceAsStream("icon.png");
+			if (is == null) {
+				System.err.println("Could not load application icon.");
+			} else {
+				this.setIconImage(ImageIO.read(is));
+			}
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
 		this.setMinimumSize(new Dimension(400, 400));
 		this.setPreferredSize(new Dimension(800, 800));
 		this.pack();

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

@@ -12,10 +12,7 @@ import javax.swing.*;
  * The menu bar that's visible atop the application.
  */
 public class EditorMenuBar extends JMenuBar {
-	private final boolean includeAdminActions;
+	public EditorMenuBar() {
-
-	public EditorMenuBar(boolean includeAdminActions) {
-		this.includeAdminActions = includeAdminActions;
 		this.add(this.buildFileMenu());
 		this.add(this.buildEditMenu());
 		this.add(this.buildHelpMenu());

src/main/resources/admin_hash.txt

@@ -1 +0,0 @@
-cfdabe75d984e5a92fb491dadc9091419d9587c049246356a488e83a75505bce

src/main/resources/html/instructions.html

@@ -12,7 +12,7 @@
 <p><em>A simple UI for editing entity-relation mapping diagrams.</em></p>
 
 <p>
-    Have you noticed any unexpected behavior? Is there something you thing would make a good addition to this application?
+    Have you noticed any unexpected behavior? Is there something you think would make a good addition to this application?
     <a href="https://github.com/andrewlalis/EntityRelationMappingEditor/issues">Create a new issue on GitHub!</a>
 </p>