diff --git a/src/main/java/de/neemann/digital/gui/Main.java b/src/main/java/de/neemann/digital/gui/Main.java
index 677941953..a76089365 100644
--- a/src/main/java/de/neemann/digital/gui/Main.java
+++ b/src/main/java/de/neemann/digital/gui/Main.java
@@ -611,7 +611,7 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
         ToolTipAction editAttributes = new ToolTipAction(Lang.get("menu_editAttributes")) {
             @Override
             public void actionPerformed(ActionEvent e) {
-                circuitComponent.editCircuitAttributes(Main.this);
+                circuitComponent.editCircuitAttributes();
             }
         }.setToolTip(Lang.get("menu_editAttributes_tt"));
 
@@ -1611,7 +1611,7 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
      */
     public static class MainBuilder {
         private File fileToOpen;
-        private Component parent;
+        private Window parent;
         private ElementLibrary library;
         private Circuit circuit;
         private boolean allowAllFileActions = true;
@@ -1641,7 +1641,7 @@ public final class Main extends JFrame implements ClosingWindowListener.ConfirmS
          * @param parent the parent component
          * @return this for chained calls
          */
-        public MainBuilder setParent(Component parent) {
+        public MainBuilder setParent(Window parent) {
             this.parent = parent;
             return this;
         }
diff --git a/src/main/java/de/neemann/digital/gui/components/AttributeDialog.java b/src/main/java/de/neemann/digital/gui/components/AttributeDialog.java
index c6e4ffd54..d50b914f3 100644
--- a/src/main/java/de/neemann/digital/gui/components/AttributeDialog.java
+++ b/src/main/java/de/neemann/digital/gui/components/AttributeDialog.java
@@ -29,7 +29,7 @@ import java.util.HashMap;
 public class AttributeDialog extends JDialog {
     private final java.util.List<EditorHolder> editors;
     private final JPanel panel;
-    private final Component parent;
+    private final Window parent;
     private final Point pos;
     private final ElementAttributes originalAttributes;
     private final ElementAttributes modifiedAttributes;
@@ -47,7 +47,7 @@ public class AttributeDialog extends JDialog {
      * @param list              the list of keys which are to edit
      * @param elementAttributes the data stored
      */
-    public AttributeDialog(Component parent, java.util.List<Key> list, ElementAttributes elementAttributes) {
+    public AttributeDialog(Window parent, java.util.List<Key> list, ElementAttributes elementAttributes) {
         this(parent, null, list, elementAttributes, false);
     }
 
@@ -59,7 +59,7 @@ public class AttributeDialog extends JDialog {
      * @param list              the list of keys which are to edit
      * @param elementAttributes the data stored
      */
-    public AttributeDialog(Component parent, Point pos, java.util.List<Key> list, ElementAttributes elementAttributes) {
+    public AttributeDialog(Window parent, Point pos, java.util.List<Key> list, ElementAttributes elementAttributes) {
         this(parent, pos, list, elementAttributes, false);
     }
 
@@ -72,8 +72,8 @@ public class AttributeDialog extends JDialog {
      * @param elementAttributes the initial data to modify
      * @param addCheckBoxes     th true check boxes behind the attributes are added
      */
-    public AttributeDialog(Component parent, Point pos, java.util.List<Key> list, ElementAttributes elementAttributes, boolean addCheckBoxes) {
-        super(SwingUtilities.getWindowAncestor(parent), Lang.get("attr_dialogTitle"), ModalityType.APPLICATION_MODAL);
+    public AttributeDialog(Window parent, Point pos, java.util.List<Key> list, ElementAttributes elementAttributes, boolean addCheckBoxes) {
+        super(parent, Lang.get("attr_dialogTitle"), ModalityType.APPLICATION_MODAL);
         this.parent = parent;
         this.pos = pos;
         this.originalAttributes = elementAttributes;
@@ -228,7 +228,7 @@ public class AttributeDialog extends JDialog {
     /**
      * @return the dialogs parent
      */
-    public Component getDialogParent() {
+    public Window getDialogParent() {
         return parent;
     }
 
@@ -246,8 +246,6 @@ public class AttributeDialog extends JDialog {
     public Main getMain() {  // ToDo: is a hack! find a better solution for getting the main frame
         if (parent instanceof Main)
             return (Main) parent;
-        if (parent instanceof CircuitComponent)
-            return ((CircuitComponent) parent).getMain();
         return null;
     }
 
diff --git a/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java b/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
index 0d3be0b62..052b38f04 100644
--- a/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
+++ b/src/main/java/de/neemann/digital/gui/components/CircuitComponent.java
@@ -391,20 +391,17 @@ public class CircuitComponent extends JComponent implements Circuit.ChangedListe
 
     /**
      * Opens the attribute editor
-     *
-     * @param parent the parent component
      */
-    public void editCircuitAttributes(Component parent) {
-        editCircuitAttributes(parent, ATTR_LIST);
+    public void editCircuitAttributes() {
+        editCircuitAttributes(ATTR_LIST);
     }
 
     /**
      * Opens the attribute editor
      *
-     * @param parent   the parent component
      * @param attrList the list of keys to edit
      */
-    public void editCircuitAttributes(Component parent, java.util.List<Key> attrList) {
+    public void editCircuitAttributes(java.util.List<Key> attrList) {
         ElementAttributes modifiedAttributes = new AttributeDialog(parent, attrList, circuit.getAttributes()).showDialog();
         if (modifiedAttributes != null)
             modify(new ModifyCircuitAttributes(modifiedAttributes));
@@ -976,14 +973,14 @@ public class CircuitComponent extends JComponent implements Circuit.ChangedListe
             if (list.size() > 0) {
                 Point p = new Point(e.getX(), e.getY());
                 SwingUtilities.convertPointToScreen(p, CircuitComponent.this);
-                AttributeDialog attributeDialog = new AttributeDialog(this, p, list, element.getElementAttributes()).setVisualElement(element);
+                AttributeDialog attributeDialog = new AttributeDialog(parent, p, list, element.getElementAttributes()).setVisualElement(element);
                 if (elementType instanceof ElementLibrary.ElementTypeDescriptionCustom) {
                     attributeDialog.addButton(Lang.get("attr_openCircuitLabel"), new ToolTipAction(Lang.get("attr_openCircuit")) {
                         @Override
                         public void actionPerformed(ActionEvent e) {
                             attributeDialog.dispose();
                             new Main.MainBuilder()
-                                    .setParent(CircuitComponent.this)
+                                    .setParent(parent)
                                     .setFileToOpen(((ElementLibrary.ElementTypeDescriptionCustom) elementType).getFile())
                                     .setLibrary(library)
                                     .denyMostFileActions()
@@ -1125,7 +1122,7 @@ public class CircuitComponent extends JComponent implements Circuit.ChangedListe
                     }
 
                 if (keyList.size() > 0) {
-                    AttributeDialog ad = new AttributeDialog(this, null, keyList, attr, true);
+                    AttributeDialog ad = new AttributeDialog(parent, null, keyList, attr, true);
                     for (Map.Entry<Key, Boolean> u : useKeyMap.entrySet())
                         ad.getCheckBoxes().get(u.getKey()).setSelected(u.getValue());
                     ElementAttributes mod = ad.showDialog();
diff --git a/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionDialog.java b/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionDialog.java
index 36f465a21..dd84ceb7c 100644
--- a/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionDialog.java
+++ b/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionDialog.java
@@ -35,8 +35,8 @@ public class TestCaseDescriptionDialog extends JDialog {
      * @param data    the data to edit
      * @param element the element to be modified
      */
-    public TestCaseDescriptionDialog(Component parent, TestCaseDescription data, VisualElement element) {
-        super(SwingUtilities.getWindowAncestor(parent),
+    public TestCaseDescriptionDialog(Window parent, TestCaseDescription data, VisualElement element) {
+        super(parent,
                 Lang.get("key_Testdata"),
                 element == null ? ModalityType.APPLICATION_MODAL : ModalityType.MODELESS);
         setDefaultCloseOperation(DISPOSE_ON_CLOSE);
@@ -72,8 +72,8 @@ public class TestCaseDescriptionDialog extends JDialog {
             buttons.add(new ToolTipAction(Lang.get("btn_addTransitions")) {
                 @Override
                 public void actionPerformed(ActionEvent e) {
-                    if (parent instanceof CircuitComponent) {
-                        CircuitComponent cc = (CircuitComponent) parent;
+                    if (parent instanceof Main) {
+                        CircuitComponent cc = ((Main) parent).getCircuitComponent();
                         try {
                             Transitions tr = new Transitions(text.getText(), cc.getCircuit().getInputNames());
                             if (tr.isNew()) {
@@ -93,9 +93,9 @@ public class TestCaseDescriptionDialog extends JDialog {
                 public void actionPerformed(ActionEvent e) {
                     try {
                         data.setDataString(text.getText());
-                        if (parent instanceof CircuitComponent) {
+                        if (parent instanceof Main) {
+                            CircuitComponent cc = ((Main) parent).getCircuitComponent();
                             element.getElementAttributes().set(TestCaseElement.TESTDATA, data);
-                            CircuitComponent cc = (CircuitComponent) parent;
                             cc.getMain().startTests();
                         }
                     } catch (ParserException | IOException e1) {
@@ -112,8 +112,8 @@ public class TestCaseDescriptionDialog extends JDialog {
                     data.setDataString(text.getText());
                     if (element != null
                             && !initialDataString.equals(data.getDataString())
-                            && parent instanceof CircuitComponent) {
-                        CircuitComponent cc = (CircuitComponent) parent;
+                            && parent instanceof Main) {
+                        CircuitComponent cc = ((Main) parent).getCircuitComponent();
                         cc.modify(new ModifyAttribute<>(element, TestCaseElement.TESTDATA, new TestCaseDescription(data)));
                     }
                     dispose();
diff --git a/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionEditor.java b/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionEditor.java
index 2617a78ad..c7c093cff 100644
--- a/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionEditor.java
+++ b/src/main/java/de/neemann/digital/gui/components/testing/TestCaseDescriptionEditor.java
@@ -19,7 +19,6 @@ import java.awt.event.ActionEvent;
 public class TestCaseDescriptionEditor extends EditorFactory.LabelEditor<TestCaseDescription> {
 
     private final TestCaseDescription data;
-    private final Key<TestCaseDescription> key;
 
     /**
      * Creates a new editor
@@ -29,7 +28,6 @@ public class TestCaseDescriptionEditor extends EditorFactory.LabelEditor<TestCas
      */
     public TestCaseDescriptionEditor(TestCaseDescription data, Key<TestCaseDescription> key) {
         this.data = new TestCaseDescription(data);
-        this.key = key;
     }
 
     @Override
@@ -44,7 +42,7 @@ public class TestCaseDescriptionEditor extends EditorFactory.LabelEditor<TestCas
         panel.add(new ToolTipAction(Lang.get("btn_edit")) {
             @Override
             public void actionPerformed(ActionEvent e) {
-                new TestCaseDescriptionDialog(panel, data, null).setVisible(true);
+                new TestCaseDescriptionDialog(SwingUtilities.getWindowAncestor(panel), data, null).setVisible(true);
             }
         }.createJButton());
 
@@ -53,12 +51,13 @@ public class TestCaseDescriptionEditor extends EditorFactory.LabelEditor<TestCas
             public void actionPerformed(ActionEvent e) {
                 try {
                     getAttributeDialog().fireOk();
-                VisualElement visualElement = TestCaseDescriptionEditor.this.getAttributeDialog().getVisualElement();
-                TestCaseDescriptionDialog dialog = new TestCaseDescriptionDialog(getAttributeDialog().getDialogParent(), data, visualElement);
-                Main main = getAttributeDialog().getMain();
-                if (main != null)
-                    main.getWindowPosManager().register("testdata", dialog);
-                dialog.setVisible(true);
+                    VisualElement visualElement = TestCaseDescriptionEditor.this.getAttributeDialog().getVisualElement();
+                    Main main = getAttributeDialog().getMain();
+                    if (main != null) {
+                        TestCaseDescriptionDialog dialog = new TestCaseDescriptionDialog(main, data, visualElement);
+                        main.getWindowPosManager().register("testdata", dialog);
+                        dialog.setVisible(true);
+                    }
                 } catch (EditorParseException e1) {
                     e1.printStackTrace();
                 }