xml - Android Studio UI PNG image overlayering a map -

im attempting add camera symbol @ bottom of application (like snapchat) overlayering map, cant seem make work. layer , imagebutton within places below layer containing map object. if reduce hight of "map-layer" works, there is, naturaly, white void on either side of camera symbol centered.

any suggestions? here picture , layout file, included whole thing in case made mistakes on causes issue. appreciated.

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent">  <linearlayout     android:orientation="horizontal"     android:layout_width="match_parent"     android:layout_height="wrap_content">      <linearlayout         android:orientation="horizontal"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:weightsum="1"         android:background="#165d38">          <linearlayout             android:orientation="horizontal"             android:layout_width="fill_parent"             android:layout_height="fill_parent"             android:layout_weight="1"             android:gravity="center_vertical">              <imagebutton                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:id="@+id/imagebutton2"                 android:src="@drawable/mark"                 android:background="#00000000" />              <textview                 android:layout_width="wrap_content"                 android:layout_height="wrap_content"                 android:text="swoop"                 android:id="@+id/textview2"                 android:textsize="18dp"                 android:gravity="center_horizontal|right" />          </linearlayout>          <imagebutton             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:id="@+id/imagebutton3"             android:src="@drawable/mr_ic_settings_light"             android:layout_weight="0"             android:backgroundtint="#00000000" />      </linearlayout>  </linearlayout>  <linearlayout     android:orientation="vertical"     android:layout_width="match_parent"     android:layout_height="fill_parent">      <fragment tools:context="net.net16.swooptest.demomaps.mapsactivity"         xmlns:android="http://schemas.android.com/apk/res/android"         xmlns:map="http://schemas.android.com/apk/res-auto"         xmlns:tools="http://schemas.android.com/tools"         android:id="@+id/map"         android:name="com.google.android.gms.maps.supportmapfragment"         android:layout_width="fill_parent"         android:layout_height="match_parent" />  </linearlayout>  <linearlayout     android:orientation="vertical"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:gravity="bottom"     android:baselinealigned="false"     android:background="#00000000">  //this camera button     <imagebutton         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:id="@+id/imagebutton4"         android:src="@drawable/abc_btn_radio_to_on_mtrl_015"         android:background="#00000000"         android:clickable="true"         android:layout_weight="1"         android:layout_gravity="center_horizontal" /> </linearlayout> 

i found answer maybe can fix problem, here link https://stackoverflow.com/a/2386929/4957589