title: How to add images on textview on some event
body: <p>In my android application, i have a list and a list header. for list header i used this layout:</p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent" android:layout_height="?android:attr/listPreferredItemHeight"
      android:weightSum="1"&gt;
  
      &lt;TextView android:text="#" android:layout_height="wrap_content"
          android:layout_width="0dp" android:background="@drawable/back"
          android:layout_weight=".05" android:gravity="center_horizontal"
          android:id="@+id/header_num"/&gt;:
      &lt;TextView android:text="Summary" android:layout_height="wrap_content"
          android:layout_width="0dp" android:background="@drawable/back"
          android:layout_weight=".55" android:gravity="center_horizontal"
          android:id="@+id/header_summ" /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p><strong>for android:background="@drawable/back":</strong></p>
  
  <pre><code>&lt;shape xmlns:android="http://schemas.android.com/apk/res/android"
      android:shape="rectangle"&gt;
      &lt;solid android:color="#ffffff" /&gt;
      &lt;stroke android:width="1dip" android:color="#4fa5d5" /&gt;
  
  
  &lt;/shape&gt;
  </code></pre>
  
  <p>Now on the basis of header item, am applying sorting on list item as:</p>
  
  <pre><code>ticketnum = (TextView) findViewById(R.id.header_num);
          ticketnum.setOnClickListener(new OnClickListener() {
              @Override
              public void onClick(View v) {
  
                  Comparator&lt;Ticket&gt; mc;
                  mc = new TicketIdComparator();
                  Collections.sort(tickets, mc);
                  System.out.println(tickets);
                  ticket_adapter = new TicketAdapter(getApplicationContext(),
                          R.layout.ticket_details_row, tickets);
                  setListAdapter(ticket_adapter);
  
                  ticket_adapter.notifyDataSetChanged();
  
              }
          });
  </code></pre>
  
  <p>Now i want  two images on this header, an upward and an downward arrow to show sorting is in ascending or descending order.</p>
  
  <p>please suggest how can i add these two images.</p>
  
  <p>Thanks.</p>