getSupportActionBar().setBackgroundDrawable(getResources().getDrawable(R.drawable.nav_bar));
getSupportActionBar().setIcon(new ColorDrawable(getResources().getColor(android.R.color.transparent)));
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
getSupportActionBar().setDisplayShowHomeEnabled(false);
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
getSupportActionBar().setHomeButtonEnabled(false);

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<ImageView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scaleType="fitXY"
    android:src="@drawable/nav_bar"/>

<TextView
    android:id="@+id/title"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Title"
    android:layout_centerInParent="true"
    android:textColor="@color/irapptheme_color"
    android:textSize="20sp"/>

<ImageButton
    android:id="@+id/btn_back"
    android:layout_width="48dp"
    android:layout_height="match_parent"
    android:background="@android:color/darker_gray"
    android:padding="12dp"
    android:layout_centerVertical="true"
    android:scaleType="fitCenter"
    android:src="@drawable/btn_back"
    android:visibility="gone"/>

<ImageButton
    android:id="@+id/btn_search"
    android:layout_width="48dp"
    android:layout_height="match_parent"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:padding="12dp"
    android:background="@android:color/transparent"
    android:src="@drawable/btn_search"
    android:visibility="gone"/>