Added image export.

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

@@ -1,9 +1,23 @@
 package nl.andrewlalis.erme.control.actions;
 
+import lombok.Setter;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+import nl.andrewlalis.erme.view.view_models.MappingModelViewModel;
+
+import javax.imageio.ImageIO;
 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.awt.geom.AffineTransform;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+import java.util.Set;
 
 public class ExportToImageAction extends AbstractAction {
 	private static ExportToImageAction instance;
@@ -15,6 +29,11 @@ public class ExportToImageAction extends AbstractAction {
 		return instance;
 	}
 
+	private File lastSelectedFile;
+
+	@Setter
+	private MappingModel model;
+
 	public ExportToImageAction() {
 		super("Export to Image");
 		this.putValue(Action.SHORT_DESCRIPTION, "Export the current diagram to an image.");
@@ -23,6 +42,66 @@ public class ExportToImageAction extends AbstractAction {
 
 	@Override
 	public void actionPerformed(ActionEvent e) {
-		System.out.println("Export to image.");
+		JFileChooser fileChooser = new JFileChooser(this.lastSelectedFile);
+		fileChooser.setFileFilter(new FileNameExtensionFilter(
+				"Image files", ImageIO.getReaderFileSuffixes()
+		));
+		if (this.lastSelectedFile != null) {
+			fileChooser.setSelectedFile(this.lastSelectedFile);
+		}
+		int choice = fileChooser.showSaveDialog((Component) e.getSource());
+		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);
+				return;
+			}
+			int i = chosenFile.getName().lastIndexOf('.');
+			String extension = "png";
+			if (i > 0) {
+				extension = chosenFile.getName().substring(i + 1);
+			} else {
+				chosenFile = new File(chosenFile.getParent(), chosenFile.getName() + '.' + extension);
+			}
+			try {
+				ImageIO.write(this.renderModel(), extension, chosenFile);
+			} catch (IOException ex) {
+				ex.printStackTrace();
+				JOptionPane.showMessageDialog(fileChooser, "An error occurred and the file could not be saved:\n" + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
+			}
+		}
+	}
+
+	private BufferedImage renderModel() {
+		BufferedImage bufferedImage = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
+		Graphics2D g2d = bufferedImage.createGraphics();
+		int minX = Integer.MAX_VALUE;
+		int minY = Integer.MAX_VALUE;
+		int maxX = Integer.MIN_VALUE;
+		int maxY = Integer.MIN_VALUE;
+		for (Relation r : model.getRelations()) {
+			Rectangle bounds = r.getViewModel().getBounds(g2d);
+			minX = Math.min(minX, bounds.x);
+			minY = Math.min(minY, bounds.y);
+			maxX = Math.max(maxX, bounds.x + bounds.width);
+			maxY = Math.max(maxY, bounds.y + bounds.height);
+		}
+		BufferedImage outputImage = new BufferedImage((maxX - minX), (maxY - minY) + 20, BufferedImage.TYPE_INT_RGB);
+		g2d = outputImage.createGraphics();
+		g2d.setColor(Color.WHITE);
+		g2d.fillRect(outputImage.getMinX(), outputImage.getMinY(), outputImage.getWidth(), outputImage.getHeight());
+		AffineTransform originalTransform = g2d.getTransform();
+		g2d.setTransform(AffineTransform.getTranslateInstance(-minX, -minY));
+
+		List<Relation> selectedRelations = this.model.getSelectedRelations();
+		this.model.getSelectedRelations().forEach(r -> r.setSelected(false));
+		new MappingModelViewModel(this.model).draw(g2d);
+		this.model.getRelations().forEach(r -> r.setSelected(selectedRelations.contains(r)));
+
+		g2d.setTransform(originalTransform);
+		g2d.setColor(Color.LIGHT_GRAY);
+		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/LoadAction.java

@@ -0,0 +1,67 @@
+package nl.andrewlalis.erme.control.actions;
+
+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;
+
+public class LoadAction extends AbstractAction {
+	private static LoadAction instance;
+
+	public static LoadAction getInstance() {
+		if (instance == null) {
+			instance = new LoadAction();
+		}
+		return instance;
+	}
+
+	private File lastSelectedFile;
+
+	@Setter
+	private DiagramPanel diagramPanel;
+
+	public LoadAction() {
+		super("Load");
+		this.putValue(SHORT_DESCRIPTION, "Load a saved diagram.");
+		this.putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_O, InputEvent.CTRL_DOWN_MASK));
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		JFileChooser fileChooser = new JFileChooser(this.lastSelectedFile);
+		FileNameExtensionFilter filter = new FileNameExtensionFilter(
+				"ERME Serialized Files",
+				"erme"
+		);
+		fileChooser.setFileFilter(filter);
+		if (this.lastSelectedFile != null) {
+			fileChooser.setSelectedFile(this.lastSelectedFile);
+		}
+		int choice = fileChooser.showOpenDialog((Component) e.getSource());
+		if (choice == JFileChooser.APPROVE_OPTION) {
+			File chosenFile = fileChooser.getSelectedFile();
+			if (chosenFile == null || chosenFile.isDirectory() || !chosenFile.exists() || !chosenFile.canRead()) {
+				JOptionPane.showMessageDialog(fileChooser, "The selected file cannot be read.", "Invalid File", JOptionPane.WARNING_MESSAGE);
+				return;
+			}
+			try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream(chosenFile))) {
+				MappingModel loadedModel = (MappingModel) ois.readObject();
+				this.lastSelectedFile = chosenFile;
+				this.diagramPanel.setModel(loadedModel);
+			} catch (IOException | ClassNotFoundException | ClassCastException 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/RedoAction.java

@@ -19,6 +19,7 @@ public class RedoAction extends AbstractAction {
 		super("Redo");
 		this.putValue(Action.SHORT_DESCRIPTION, "Redoes a previously undone action.");
 		this.putValue(Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK | InputEvent.SHIFT_DOWN_MASK));
+		this.setEnabled(false);
 	}
 
 	@Override

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

@@ -40,6 +40,9 @@ public class SaveAction extends AbstractAction {
 				"erme"
 		);
 		fileChooser.setFileFilter(filter);
+		if (this.lastSelectedFile != null) {
+			fileChooser.setSelectedFile(this.lastSelectedFile);
+		}
 		int choice = fileChooser.showSaveDialog((Component) e.getSource());
 		if (choice == JFileChooser.APPROVE_OPTION) {
 			File chosenFile = fileChooser.getSelectedFile();
@@ -56,6 +59,7 @@ public class SaveAction extends AbstractAction {
 				this.lastSelectedFile = chosenFile;
 				JOptionPane.showMessageDialog(fileChooser, "File saved successfully.", "Success", JOptionPane.INFORMATION_MESSAGE);
 			} catch (IOException ex) {
+				ex.printStackTrace();
 				JOptionPane.showMessageDialog(fileChooser, "An error occurred and the file could not be saved:\n" + ex.getMessage(), "Error", JOptionPane.ERROR_MESSAGE);
 			}
 		}

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

@@ -19,6 +19,7 @@ public class UndoAction extends AbstractAction {
 		super("Undo");
 		this.putValue(Action.SHORT_DESCRIPTION, "Undo the last action.");
 		this.putValue(Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_Z, InputEvent.CTRL_DOWN_MASK));
+		this.setEnabled(false);
 	}
 
 	@Override

src/main/java/nl/andrewlalis/erme/control/actions/edits/AddAttributeAction.java

@@ -0,0 +1,74 @@
+package nl.andrewlalis.erme.control.actions.edits;
+
+import lombok.Setter;
+import nl.andrewlalis.erme.model.Attribute;
+import nl.andrewlalis.erme.model.AttributeType;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.InputEvent;
+import java.awt.event.KeyEvent;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Stream;
+
+public class AddAttributeAction extends AbstractAction {
+	private static AddAttributeAction instance;
+
+	public static AddAttributeAction getInstance() {
+		if (instance == null) {
+			instance = new AddAttributeAction();
+		}
+		return instance;
+	}
+
+	@Setter
+	private MappingModel model;
+
+	public AddAttributeAction() {
+		super("Add Attribute");
+		this.putValue(SHORT_DESCRIPTION, "Add an attribute to the selected relation.");
+		this.putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_T, InputEvent.CTRL_DOWN_MASK));
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		List<Relation> selectedRelations = this.model.getSelectedRelations();
+		if (selectedRelations.size() != 1) {
+			JOptionPane.showMessageDialog(
+					(Component) e.getSource(),
+					"A single relation must be selected to add an attribute.",
+					"Single Relation Required",
+					JOptionPane.WARNING_MESSAGE
+			);
+			return;
+		}
+		Relation r = selectedRelations.get(0);
+		Component c = (Component) e.getSource();
+		String name = JOptionPane.showInputDialog(c, "Enter the name of the attribute.", "Attribute Name", JOptionPane.PLAIN_MESSAGE);
+		Integer index = (Integer) JOptionPane.showInputDialog(
+				c,
+				"Select the index to insert this attribute at.",
+				"Attribute Index",
+				JOptionPane.PLAIN_MESSAGE,
+				null,
+				Stream.iterate(0, n -> n + 1).limit(r.getAttributes().size() + 1).toArray(),
+				r.getAttributes().size()
+		);
+		AttributeType type = (AttributeType) JOptionPane.showInputDialog(
+				c,
+				"Select the type this attribute is.",
+				"Attribute Type",
+				JOptionPane.PLAIN_MESSAGE,
+				null,
+				AttributeType.values(),
+				AttributeType.PLAIN
+		);
+		if (name != null && index != null && type != null) {
+			r.addAttribute(new Attribute(r, type, name), index);
+		}
+	}
+}

src/main/java/nl/andrewlalis/erme/control/actions/edits/AddRelationAction.java

@@ -0,0 +1,44 @@
+package nl.andrewlalis.erme.control.actions.edits;
+
+import lombok.Setter;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.InputEvent;
+import java.awt.event.KeyEvent;
+
+public class AddRelationAction extends AbstractAction {
+	private static AddRelationAction instance;
+
+	public static AddRelationAction getInstance() {
+		if (instance == null) {
+			instance = new AddRelationAction();
+		}
+		return instance;
+	}
+
+	@Setter
+	private MappingModel model;
+
+	public AddRelationAction() {
+		super("Add Relation");
+		this.putValue(SHORT_DESCRIPTION, "Add a new relation to the diagram.");
+		this.putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_R, InputEvent.CTRL_DOWN_MASK));
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		String name = JOptionPane.showInputDialog(
+				(Component) e.getSource(),
+				"Enter the name of the relation.",
+				"Add Relation",
+				JOptionPane.PLAIN_MESSAGE
+		);
+		if (name != null) {
+			this.model.addRelation(new Relation(this.model, new Point(0, 0), name));
+		}
+	}
+}

src/main/java/nl/andrewlalis/erme/control/actions/edits/RemoveAttributeAction.java

@@ -0,0 +1,61 @@
+package nl.andrewlalis.erme.control.actions.edits;
+
+import lombok.Setter;
+import nl.andrewlalis.erme.model.Attribute;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.InputEvent;
+import java.awt.event.KeyEvent;
+import java.util.List;
+import java.util.stream.Stream;
+
+public class RemoveAttributeAction extends AbstractAction {
+	private static RemoveAttributeAction instance;
+
+	public static RemoveAttributeAction getInstance() {
+		if (instance == null) {
+			instance = new RemoveAttributeAction();
+		}
+		return instance;
+	}
+
+	@Setter
+	private MappingModel model;
+
+	public RemoveAttributeAction() {
+		super("Remove Attribute");
+		this.putValue(SHORT_DESCRIPTION, "Remove an attribute from a relation.");
+		this.putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_T, InputEvent.CTRL_DOWN_MASK | InputEvent.SHIFT_DOWN_MASK));
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		List<Relation> selectedRelations = this.model.getSelectedRelations();
+		if (selectedRelations.size() != 1 || selectedRelations.get(0).getAttributes().isEmpty()) {
+			JOptionPane.showMessageDialog(
+					(Component) e.getSource(),
+					"A single relation with at least one attribute must be selected to remove an attribute.",
+					"Single Relation With Attribute Required",
+					JOptionPane.WARNING_MESSAGE
+			);
+			return;
+		}
+		Relation r = selectedRelations.get(0);
+		Attribute attribute = (Attribute) JOptionPane.showInputDialog(
+				(Component) e.getSource(),
+				"Select the index to insert this attribute at.",
+				"Attribute Index",
+				JOptionPane.PLAIN_MESSAGE,
+				null,
+				r.getAttributes().toArray(new Attribute[0]),
+				r.getAttributes().get(0)
+		);
+		if (attribute != null) {
+			r.removeAttribute(attribute);
+		}
+	}
+}

src/main/java/nl/andrewlalis/erme/control/actions/edits/RemoveRelationAction.java

@@ -0,0 +1,47 @@
+package nl.andrewlalis.erme.control.actions.edits;
+
+import lombok.Setter;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.InputEvent;
+import java.awt.event.KeyEvent;
+
+public class RemoveRelationAction extends AbstractAction {
+	private static RemoveRelationAction instance;
+
+	public static RemoveRelationAction getInstance() {
+		if (instance == null) {
+			instance = new RemoveRelationAction();
+		}
+		return instance;
+	}
+
+	@Setter
+	private MappingModel model;
+
+	public RemoveRelationAction() {
+		super("Remove Relation");
+		this.putValue(SHORT_DESCRIPTION, "Remove a relation from the diagram.");
+		this.putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(KeyEvent.VK_R, InputEvent.CTRL_DOWN_MASK | InputEvent.SHIFT_DOWN_MASK));
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		if (this.model.getSelectedRelations().isEmpty()) {
+			JOptionPane.showMessageDialog(
+					(Component) e.getSource(),
+					"No relations selected. Select at least one relation to remove.",
+					"No Relations Selected",
+					JOptionPane.WARNING_MESSAGE
+			);
+			return;
+		}
+		for (Relation r : this.model.getSelectedRelations()) {
+			this.model.removeRelation(r);
+		}
+	}
+}

src/main/java/nl/andrewlalis/erme/control/diagram/DiagramMouseListener.java

@@ -3,6 +3,7 @@ package nl.andrewlalis.erme.control.diagram;
 import nl.andrewlalis.erme.model.MappingModel;
 import nl.andrewlalis.erme.model.Relation;
 import nl.andrewlalis.erme.view.DiagramPanel;
+import nl.andrewlalis.erme.view.DiagramPopupMenu;
 
 import java.awt.*;
 import java.awt.event.ActionEvent;
@@ -24,6 +25,8 @@ public class DiagramMouseListener extends MouseAdapter {
 	 * relations, if CTRL is not held down.
 	 * - If the click occurs within at least one relation, select the first one,
 	 * and deselect all others if CTRL is not held down.
+	 * - If the user did a right-click, try to open a popup menu with some
+	 * possible actions.
 	 * @param e The mouse event.
 	 */
 	@Override
@@ -43,6 +46,12 @@ public class DiagramMouseListener extends MouseAdapter {
 				break;
 			}
 		}
+
+		if (e.getButton() == MouseEvent.BUTTON3) {
+			DiagramPopupMenu popupMenu = new DiagramPopupMenu(this.model);
+			popupMenu.show(panel, e.getX(), e.getY());
+		}
+
 		this.model.fireChangedEvent();
 	}
 

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

@@ -43,4 +43,9 @@ public class Attribute implements Serializable {
 	public int hashCode() {
 		return Objects.hash(type, name);
 	}
+
+	@Override
+	public String toString() {
+		return this.getName() + ":" + this.getType().name();
+	}
 }

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

@@ -4,8 +4,10 @@ import lombok.Getter;
 
 import java.io.Serializable;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Objects;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 /**
  * This model contains all the information about a single mapping diagram,
@@ -15,7 +17,7 @@ public class MappingModel implements Serializable {
 	@Getter
 	private final Set<Relation> relations;
 
-	private transient final Set<ModelChangeListener> changeListeners;
+	private transient Set<ModelChangeListener> changeListeners;
 
 	public MappingModel() {
 		this.relations = new HashSet<>();
@@ -34,7 +36,14 @@ public class MappingModel implements Serializable {
 		}
 	}
 
+	public List<Relation> getSelectedRelations() {
+		return this.relations.stream().filter(Relation::isSelected).collect(Collectors.toList());
+	}
+
 	public void addChangeListener(ModelChangeListener listener) {
+		if (this.changeListeners == null) {
+			this.changeListeners = new HashSet<>();
+		}
 		this.changeListeners.add(listener);
 		listener.onModelChanged();
 	}

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

@@ -20,14 +20,13 @@ public class Relation implements Serializable {
 	private final List<Attribute> attributes;
 
 	private transient boolean selected;
-	private final transient RelationViewModel viewModel;
+	private transient RelationViewModel viewModel;
 
 	public Relation(MappingModel model, Point position, String name) {
 		this.model = model;
 		this.position = position;
 		this.name = name;
 		this.attributes = new ArrayList<>();
-		this.viewModel = new RelationViewModel(this);
 	}
 
 	public void setPosition(Point position) {
@@ -47,12 +46,24 @@ public class Relation implements Serializable {
 		this.model.fireChangedEvent();
 	}
 
+	public void addAttribute(Attribute attribute, int index) {
+		this.attributes.add(index, attribute);
+		this.model.fireChangedEvent();
+	}
+
 	public void removeAttribute(Attribute attribute) {
 		if (this.attributes.remove(attribute)) {
 			this.model.fireChangedEvent();
 		}
 	}
 
+	public RelationViewModel getViewModel() {
+		if (this.viewModel == null) {
+			this.viewModel = new RelationViewModel(this);
+		}
+		return this.viewModel;
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) return true;

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

@@ -1,7 +1,13 @@
 package nl.andrewlalis.erme.view;
 
 import lombok.Getter;
+import nl.andrewlalis.erme.control.actions.ExportToImageAction;
+import nl.andrewlalis.erme.control.actions.LoadAction;
 import nl.andrewlalis.erme.control.actions.SaveAction;
+import nl.andrewlalis.erme.control.actions.edits.AddAttributeAction;
+import nl.andrewlalis.erme.control.actions.edits.AddRelationAction;
+import nl.andrewlalis.erme.control.actions.edits.RemoveAttributeAction;
+import nl.andrewlalis.erme.control.actions.edits.RemoveRelationAction;
 import nl.andrewlalis.erme.control.diagram.DiagramMouseListener;
 import nl.andrewlalis.erme.model.MappingModel;
 import nl.andrewlalis.erme.model.ModelChangeListener;
@@ -36,7 +42,7 @@ public class DiagramPanel extends JPanel implements ModelChangeListener {
 		DiagramMouseListener listener = new DiagramMouseListener(newModel);
 		this.addMouseListener(listener);
 		this.addMouseMotionListener(listener);
-		SaveAction.getInstance().setModel(newModel);
+		this.updateActionModels();
 		this.repaint();
 	}
 
@@ -63,4 +69,17 @@ public class DiagramPanel extends JPanel implements ModelChangeListener {
 		this.revalidate();
 		this.repaint();
 	}
+
+	/**
+	 * Updates all the action singletons with the latest model information.
+	 */
+	private void updateActionModels() {
+		SaveAction.getInstance().setModel(this.model);
+		LoadAction.getInstance().setDiagramPanel(this);
+		ExportToImageAction.getInstance().setModel(this.model);
+		AddRelationAction.getInstance().setModel(this.model);
+		RemoveRelationAction.getInstance().setModel(this.model);
+		AddAttributeAction.getInstance().setModel(this.model);
+		RemoveAttributeAction.getInstance().setModel(this.model);
+	}
 }

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

@@ -0,0 +1,29 @@
+package nl.andrewlalis.erme.view;
+
+import nl.andrewlalis.erme.control.actions.ExportToImageAction;
+import nl.andrewlalis.erme.control.actions.edits.AddAttributeAction;
+import nl.andrewlalis.erme.control.actions.edits.AddRelationAction;
+import nl.andrewlalis.erme.control.actions.edits.RemoveAttributeAction;
+import nl.andrewlalis.erme.control.actions.edits.RemoveRelationAction;
+import nl.andrewlalis.erme.model.MappingModel;
+import nl.andrewlalis.erme.model.Relation;
+
+import javax.swing.*;
+import java.util.List;
+
+public class DiagramPopupMenu extends JPopupMenu {
+	public DiagramPopupMenu(MappingModel model) {
+		List<Relation> selectedRelations = model.getSelectedRelations();
+		if (selectedRelations.size() == 0) {
+			this.add(AddRelationAction.getInstance());
+			this.add(ExportToImageAction.getInstance());
+		}
+		if (selectedRelations.size() > 0) {
+			this.add(RemoveRelationAction.getInstance());
+		}
+		if (selectedRelations.size() == 1) {
+			this.add(AddAttributeAction.getInstance());
+			this.add(RemoveAttributeAction.getInstance());
+		}
+	}
+}

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

@@ -1,6 +1,10 @@
 package nl.andrewlalis.erme.view;
 
 import nl.andrewlalis.erme.control.actions.*;
+import nl.andrewlalis.erme.control.actions.edits.AddAttributeAction;
+import nl.andrewlalis.erme.control.actions.edits.AddRelationAction;
+import nl.andrewlalis.erme.control.actions.edits.RemoveAttributeAction;
+import nl.andrewlalis.erme.control.actions.edits.RemoveRelationAction;
 
 import javax.swing.*;
 
@@ -15,21 +19,23 @@ public class EditorMenuBar extends JMenuBar {
 
 	private JMenu buildFileMenu() {
 		JMenu menu = new JMenu("File");
-		JMenuItem saveItem = new JMenuItem(SaveAction.getInstance());
+		menu.add(SaveAction.getInstance());
-		menu.add(saveItem);
+		menu.add(LoadAction.getInstance());
-		JMenuItem exportAsImageItem = new JMenuItem(ExportToImageAction.getInstance());
+		menu.add(ExportToImageAction.getInstance());
-		menu.add(exportAsImageItem);
+		menu.addSeparator();
-		JMenuItem exitItem = new JMenuItem(ExitAction.getInstance());
+		menu.add(ExitAction.getInstance());
-		menu.add(exitItem);
 		return menu;
 	}
 
 	private JMenu buildEditMenu() {
 		JMenu menu = new JMenu("Edit");
-		JMenuItem undoItem = new JMenuItem(UndoAction.getInstance());
+		menu.add(AddRelationAction.getInstance());
-		menu.add(undoItem);
+		menu.add(RemoveRelationAction.getInstance());
-		JMenuItem redoItem = new JMenuItem(RedoAction.getInstance());
+		menu.add(AddAttributeAction.getInstance());
-		menu.add(redoItem);
+		menu.add(RemoveAttributeAction.getInstance());
+		menu.addSeparator();
+		menu.add(UndoAction.getInstance());
+		menu.add(RedoAction.getInstance());
 		return menu;
 	}
 }