title: listview is populated with same value multiple times during multiple button clicks
body: <p>I have got a xml file with listview in a file list.xml</p>
  
  <pre><code>    &lt;LinearLayout&gt;
  
  &lt;Button
      android:id="@+id/countryfilter"
      android:layout_width="match_parent"
      android:layout_height="0dp"
      android:layout_weight="1"
      android:text="Load Country data"/&gt;
  
  
  &lt;Button
      android:id="@+id/domain_filter"
      android:layout_width="match_parent"
      android:layout_height="0dp"
      android:layout_weight="1"
      android:text="Load Domain data"/&gt;
  
      &lt;ListView
                  android:id="@+id/listContents"
                  android:layout_width="wrap_content"
                  android:visibility="gone"
                  android:layout_height="wrap_content"&gt;
              &lt;/ListView&gt;
       &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Following is the code that I have within row.xml</p>
  
  <pre><code> &lt;CheckedTextView
          android:id="@+id/text1"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:text="Some text here"
          android:textSize="18sp"
          android:gravity="center_vertical"
          android:clickable="true"
          android:checkMark="?android:attr/listChoiceIndicatorMultiple"
          android:focusable="true"
          android:checked="false"
          android:onClick="toggle"/&gt;
  </code></pre>
  
  <p>During run time, the listview will be made made visible and its data will be set.</p>
  
  <p>Here Im setting onClickListener for load country list button. Countrylist item has got list of some countries</p>
  
  <pre><code>countryListBtn.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              lv.setVisibility(View.VISIBLE);
              initCountryList();
  
              customAdapter = new CustomAdapter(
                      getApplicationContext(), R.layout.filters, android.R.id.text1, countryList
              );
              lv.setAdapter(customAdapter);
          }
      });
  </code></pre>
  
  <p>Here Im setting onClickListener for load domain list button. domainList contains list of domains</p>
  
  <pre><code>domainListBtn.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {
              lv.setVisibility(View.VISIBLE);
              initDomainList();
              domainAdapter = new CustomAdapter(getApplicationContext(), R.layout.filters, android.R.id.text1, domainList
              );
              lv.setAdapter(domainAdapter);
          }
      });
  </code></pre>
  
  <p>The problem  is that,</p>
  
  <p>listview is populated with values each time when buttons are clicked. so the listview has got  same values that are being displayed multiple times.</p>