android - Prevent view overlapping in RelativeLayout -

i'm trying accomplish simple layout task, i'm stuck view overlapping in relativelayout.

screenshot:

the title textview should centered (both vertically , horizontally). problem when title bit longer , covers button.

the desired behaviour title textview aligns left button, or trims (e.g. singleline).

here xml:

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:orientation="vertical">      <relativelayout         android:layout_width="match_parent"         android:layout_height="50dp"         android:background="#ffffff">          <linearlayout             android:id="@+id/backbutton"             android:layout_width="100dp"             android:layout_height="match_parent"             android:background="#cccccc">              <textview                 android:layout_width="wrap_content"                 android:layout_height="match_parent"                 android:gravity="center"                 android:text=" < back"                 android:textsize="20sp" />         </linearlayout>          <textview             android:layout_width="wrap_content"             android:layout_height="match_parent"             android:layout_centerhorizontal="true"             android:gravity="start|center_vertical"             android:text="centered title"             android:textsize="22sp" />     </relativelayout>      <relativelayout         android:layout_width="match_parent"         android:layout_height="50dp"         android:layout_margintop="30dp"         android:background="#ffffff">          <linearlayout             android:id="@+id/backbutton2"             android:layout_width="100dp"             android:layout_height="match_parent"             android:background="#cccccc">              <textview                 android:layout_width="wrap_content"                 android:layout_height="match_parent"                 android:gravity="center"                 android:text=" < back"                 android:textsize="20sp" />         </linearlayout>          <textview             android:layout_width="wrap_content"             android:layout_height="match_parent"             android:layout_centerhorizontal="true"             android:gravity="center"             android:text="a long centered title"             android:textsize="22sp" />     </relativelayout> </linearlayout> 

i don't think can via xml. calculate @ runtime. put text textview , calculate width in pixels. default centered, but, if width bigger screenwidth - 2 * backbuttonwidth, shouldn't centered aligned button edge , trimmed @ end.