title: Android NoClassDefFoundError at OnDraw
body: <p>I'm having a NoClassDefFoundError error at this line :</p>
  
  <pre><code>vto.addOnDrawListener(new OnDrawListener() {
  </code></pre>
  
  <p>On this code :</p>
  
  <pre><code>vto = visibleListView.getViewTreeObserver();
  vto.addOnDrawListener(new OnDrawListener() {
  
      @Override
      public void onDraw() {
          Log.v("DRAWING", "DRAWN");
  
      }
  });
  </code></pre>
  
  <p>Here is the error message :</p>
  
  <pre><code>12-23 21:38:49.068: E/AndroidRuntime(24508): FATAL EXCEPTION: main
  12-23 21:38:49.068: E/AndroidRuntime(24508): java.lang.NoClassDefFoundError: com.adylitica.activity.NotesActivity$14
  12-23 21:38:49.068: E/AndroidRuntime(24508):    at com.adylitica.activity.NotesActivity.onStart(NotesActivity.java:1095)
  12-23 21:38:49.068: E/AndroidRuntime(24508):    at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1136)
  </code></pre>
  
  <p>Note that the NotesActivity class is the one I'm currently running the code above.</p>
  
  <p>Ask for more details, thanks.</p>