title: CheckBoxPreference and dependency
body: <p>I've a checkbox and a ListPreference, I'd like disable/enable ListPreference by checkbox. I read a lot and I found is possible only using java (and not by xml). Is it correct? Now, after read the value of "checkboxPref" (boolean true/false) I don't how do.</p>
  
  <pre><code>SharedPreferences prefs3 = PreferenceManager.getDefaultSharedPreferences(this);
        listener = new SharedPreferences.OnSharedPreferenceChangeListener() {
            public void onSharedPreferenceChanged(SharedPreferences prefs, String listpref) {       
  
                CheckboxPreference = prefs.getBoolean("checkboxPref", true);
                }   };
  
        prefs3.registerOnSharedPreferenceChangeListener(listener);
  </code></pre>
  
  <p>preferences.xml:</p>
  
  <pre><code>&lt;CheckBoxPreference
                          android:title="Notifify"
                          android:defaultValue="true"
                          android:key="checkboxPref" /&gt;
              &lt;ListPreference
           android:entries="@array/numberOptions"
           android:entryValues="@array/numberValues"
           android:key="number"
           android:title="Number" /&gt;
  </code></pre>