small refactor

Author: a544jh

tmc-plugin/src/fi/helsinki/cs/tmc/ui/PreferencesUIFactory.java

@@ -85,8 +85,7 @@ public void showPreferencesDialog(final ActionListener dialogListener) {
         ActionListener closeListener = new ActionListener() {
             @Override
             public void actionPerformed(ActionEvent e) {
-                panel = null;
-                dialog = null;
+                destroyDialog();
                 dialogListener.actionPerformed(e);
             }
         };
@@ -102,8 +101,7 @@ public void actionPerformed(ActionEvent e) {
         dialog.addWindowListener(new WindowAdapter() {
             @Override
             public void windowClosed(WindowEvent we) {
-                panel = null;
-                dialog = null;
+                destroyDialog();
             }
         });
         SwingUtilities.invokeLater(new Runnable() {
@@ -113,4 +111,9 @@ public void run() {
             }
         });
     }
+
+    private void destroyDialog() {
+        panel = null;
+        dialog = null;
+    }
 }