title: Android: How to set drawable visible
body: <p>This is my code :</p>
  
  <pre><code>&lt;TextView
                  android:id="@+id/error_text"
                  android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:layout_marginBottom="2dp"
                  android:drawablePadding="5dp"
                  android:gravity="center"
                  android:drawableRight="@drawable/error_image"
                  android:textColor="#aa0000"
                  android:textStyle="bold"
                  android:textSize="16dp"/&gt;
  </code></pre>
  
  <p>i have a drawable that i want to set it invisible and then when error occurred drawable appears.How can i do it?</p>