RelativeLayout, align left/right for two buttons, align center for one

Question

I'm using RelativeLayout for displaying one button or two buttons. For the two buttons case, they need to be left/right aligned, for one button case, it needs to be centered.

<RelativeLayout>
  <Button
    android:id="@+id/action"
    android:layout_alignParentLeft="true"/>
  <Button
    android:id="@+id/dismiss"
    android:layout_alignParentRight="true"/>
</RelativeLayout>

I changed the dismiss button to View.GONE for one button case, but action button still aligns to left - Are there any non-programmatical way to align it center?

Answer 1

<LinearLayout
  android:orientation="horizontal">
  <Button
    android:id="@+id/action"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1"/>
  <Button
    android:id="@+id/dismiss"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_weight="1" />
</LinearLayout>