diff --git a/src/main/java/GUI/GUI.java b/src/main/java/GUI/GUI.java
index 48c94d8..0d4718b 100644
--- a/src/main/java/GUI/GUI.java
+++ b/src/main/java/GUI/GUI.java
@@ -12,7 +12,7 @@ import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.util.ArrayList;
 
-public class GUI extends JFrame implements ActionListener {
+public class GUI extends JFrame {
     private JPanel mainPanel;
     private JPanel agendaPanel;
     private JPanel arrowPanel;
@@ -56,10 +56,10 @@ public class GUI extends JFrame implements ActionListener {
         this.renderMenu();
 
         agenda = new Agenda(agendaPanel, this.currentPage, this.currentCompetition);
-        previousButton.addActionListener(this);
-        nextButton.addActionListener(this);
-        menuItemAddProj.addActionListener(this);
-        menuItemRemoveProj.addActionListener(this);
+        previousButton.addActionListener(e -> nextPreviousPage(false));
+        nextButton.addActionListener(e -> nextPreviousPage(true));
+        menuItemAddProj.addActionListener(e -> agenda.openDialog(ProjectionType.ADD));
+        menuItemRemoveProj.addActionListener(e -> agenda.openDialog(ProjectionType.REMOVE));
         setVisible(true);
     }
 
@@ -73,34 +73,22 @@ public class GUI extends JFrame implements ActionListener {
         }
     }
 
-    @Override
-    public void actionPerformed(ActionEvent e) {
-        Object source = e.getSource();
-        if (source == previousButton) {
-            this.currentPage--;
-            Agenda agenda = new Agenda(agendaPanel, this.currentPage, this.currentCompetition);
-            this.currentPage = agenda.getCurrentPage();
-            this.repaint();
-            this.revalidate();
-        } else if (source == nextButton) {
-            this.currentPage++;
-            Agenda agenda = new Agenda(agendaPanel, this.currentPage, this.currentCompetition);
-            this.currentPage = agenda.getCurrentPage();
-
-            this.repaint();
-            this.revalidate();
-        } else if (source == this.menuItemAddProj) {
-            agenda.openDialog(ProjectionType.ADD);
-        } else if (source == this.menuItemRemoveProj) {
-            agenda.openDialog(ProjectionType.REMOVE);
-        }
+    private void nextPreviousPage(boolean next) {
+        if (next)
+            currentPage++;
+        else
+            currentPage--;
+        agenda = new Agenda(agendaPanel, currentPage, currentCompetition);
+        currentPage = agenda.getCurrentPage();
+        repaint();
+        revalidate();
     }
 
     private void switchAgenda(Competition competition) {
-        this.currentCompetition = competition;
-        this.agenda = new Agenda(agendaPanel, 0, this.currentCompetition);
-        this.repaint();
-        this.revalidate();
+        currentCompetition = competition;
+        agenda = new Agenda(agendaPanel, 0, currentCompetition);
+        repaint();
+        revalidate();
     }
 
     private void createUIComponents() {
diff --git a/src/main/java/GUI/ProjectionHandler.java b/src/main/java/GUI/ProjectionHandler.java
index 00746ee..60313c1 100644
--- a/src/main/java/GUI/ProjectionHandler.java
+++ b/src/main/java/GUI/ProjectionHandler.java
@@ -96,11 +96,7 @@ public class ProjectionHandler extends JDialog {
         slotComboBox.addActionListener(actionEvent -> updateRooms());
         cancelButton.addActionListener(actionEvent -> dispose());
         confirmButton.addActionListener(actionEvent -> confirm());
-        contentPane.registerKeyboardAction(new ActionListener() {
-            public void actionPerformed(ActionEvent e) {
-                dispose();
-            }
-        }, KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
+        contentPane.registerKeyboardAction(e -> dispose(), KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
     }
 
     private void onCancel() {
diff --git a/src/main/java/GUI/ProjectionSelecter.java b/src/main/java/GUI/ProjectionSelecter.java
index 3a96796..53871dc 100644
--- a/src/main/java/GUI/ProjectionSelecter.java
+++ b/src/main/java/GUI/ProjectionSelecter.java
@@ -29,17 +29,9 @@ public class ProjectionSelecter extends JDialog {
         getRootPane().setDefaultButton(buttonOK);
         ProjectionTableModel pTM = new ProjectionTableModel(projections);
         table1.setModel(pTM);
-        buttonOK.addActionListener(new ActionListener() {
-            public void actionPerformed(ActionEvent e) {
-                onOK();
-            }
-        });
+        buttonOK.addActionListener(e -> onOK());
 
-        buttonCancel.addActionListener(new ActionListener() {
-            public void actionPerformed(ActionEvent e) {
-                onCancel();
-            }
-        });
+        buttonCancel.addActionListener(e -> onCancel());
         table1.addMouseListener(
                 new MouseAdapter() {
                     @Override
@@ -55,7 +47,7 @@ public class ProjectionSelecter extends JDialog {
                     }
                 }
         );
-        // call onCancel() when cross is clicked
+
         setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
         addWindowListener(new WindowAdapter() {
             public void windowClosing(WindowEvent e) {
@@ -63,20 +55,15 @@ public class ProjectionSelecter extends JDialog {
             }
         });
 
-        // call onCancel() on ESCAPE
-        contentPane.registerKeyboardAction(new ActionListener() {
-            public void actionPerformed(ActionEvent e) {
-                onCancel();
-            }
-        }, KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
+        contentPane.registerKeyboardAction(e -> onCancel(), KeyStroke.getKeyStroke(KeyEvent.VK_ESCAPE, 0), JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
     }
+
     private void onOK() {
         agenda.openDialog(ProjectionType.EDIT, currentProjection);
         dispose();
     }
 
     private void onCancel() {
-        // add your code here if necessary
         dispose();
     }