title: How to center image vertically in this RelativeLayout
body: <p>I have below layout which basically show "messages" as bubble slimier to built-in "Messages".
  I just need to show also an arrow image on the right, th eimage is shown, but I need it to be centered vertically. 
  I tried to add " <code>android:gravity="center_vertical"</code> to image, but it had no effect.</p>
  
  <p>any clue?</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="wrap_content" &gt;
      &lt;LinearLayout 
          android:id="@+id/wrapper"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content" 
          android:background="#00DBE2ED" &gt;
  
          &lt;RelativeLayout
              android:id="@+id/wrapper2"
              android:layout_width="fill_parent"
              android:layout_height="wrap_content"
              android:background="#00DBE2ED" &gt;
  
              &lt;EditText
                  android:id="@+id/comment"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:editable="false" 
                  android:layout_marginTop="5dip"
                  android:layout_marginRight="5dip"
                  android:layout_marginLeft="5dip"
                  android:background="@drawable/bubble_yellow"
                  android:paddingLeft="10dip"
                  android:text="Hello bubbles!"
                  android:textColor="@android:color/primary_text_light" /&gt;
              &lt;TextView
                  android:id="@+id/sender"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_margin="0dip"
                  android:paddingLeft="5dip"
                  android:paddingRight="2dip"
                  android:text="Hello bubbles!"
                  android:textColor="#b9dcdcdc"
                  android:textSize="11sp"    
                  android:layout_below="@+id/comment" /&gt;
              &lt;ImageView
                  android:id="@+id/aquaplayicon"
                  android:src="@drawable/aquaplayicon"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:clickable="true"
                  android:onClick="onClickGirl"
                  android:layout_alignParentRight="true"
                  android:paddingRight="3dip"
                  android:gravity="center_vertical" /&gt;
  
          &lt;/RelativeLayout&gt;
  
  
      &lt;/LinearLayout&gt;
  
  
  &lt;/LinearLayout&gt;
  </code></pre>