nextcloud-android/res/drawable/action_item_btn.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ownCloud Android client application

  Copyright (C) 2012  Bartek Przybylski
  Copyright (C) 2012-2013 ownCloud Inc.

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
-->
<selector xmlns:android="http://schemas.android.com/apk/res/android"
    android:dither="true">

    <item 
    	android:state_window_focused="false"
        android:drawable="@android:color/transparent" />
    <item 
    	android:state_pressed="true"
        android:drawable="@drawable/action_item_selected"/>
    <item 
    	android:state_focused="true"
        android:drawable="@drawable/action_item_selected"/>
    <item
        android:drawable="@android:color/transparent"/>
        
</selector>