title: Add a 2d library on Android studio ( withwith preexisting layout files )
body: <p>I was programming a menu with different buttons. Know, if i click on 1 button ( mental arithmetic for example ), I should be open a 2D basic game.
  I searched libraries that could help me and I found LibGDX and AndEngine.
  But there is a problem : I cannot Add LibGDX to my Project there is gradle's build problem. And the same with AndEngine. </p>
  
  <p>How can I add a 2D game ( write in java ) to my initial project ? Knowing there is problems with the importing project ( on Android Studio ) 
  Thanks</p>
  
  <p>Edit : I follow the tutorial and now there is my problem : I don't know how I can add my Layout files to the project. I want to start the Android Emulator with my xml file ( with the 5 buttons ) and currently my project start with libGDX ( with badlogic's picture and a red screen ) </p>
  
  <p>Second Edit : I finally solve my problem : I change a Line in my manifest.xml and I didn't know there was a line who start the application </p>