This code will display the image and sound files available in “/Sys/”

sysFiles.js

var arr=["/Sys/Img/AScript.png","/Sys/Img/Add.png","/Sys/Img/BarA.png","/Sys/Img/BlackBack.jpg","/Sys/Img/BlueBack.jpg","/Sys/Img/Bulb.png","/Sys/Img/Color.png","/Sys/Img/Connect.png","/Sys/Img/Droid1.png","/Sys/Img/Droid2.png","/Sys/Img/Eagle1.png","/Sys/Img/Eagle2.png","/Sys/Img/Exit.png","/Sys/Img/Explode1.png","/Sys/Img/Explode2.png","/Sys/Img/Explode3.png","/Sys/Img/Explode4.png","/Sys/Img/Explode5.png","/Sys/Img/Files.png","/Sys/Img/Forward.png","/Sys/Img/GreenBack.jpg","/Sys/Img/Hello.png","/Sys/Img/Icon.png","/Sys/Img/JoyPad.png","/Sys/Img/Layout.png","/Sys/Img/Left.png","/Sys/Img/Light.png","/Sys/Img/Mic.png","/Sys/Img/NxtConn.png","/Sys/Img/Pillar.png","/Sys/Img/PillarTop.png","/Sys/Img/Play.png","/Sys/Img/Refresh.png","/Sys/Img/Reverse.png","/Sys/Img/Right.png","/Sys/Img/Settings.png","/Sys/Img/Sky.jpg","/Sys/Img/Sound.png","/Sys/Img/Splat.png","/Sys/Img/Spring.png","/Sys/Img/Sprint.png","/Sys/Img/StarField.jpg","/Sys/Img/Tab.png","/Sys/Img/TabHi.png","/Sys/Img/Tile.png","/Sys/Img/Touch.png","/Sys/Img/Ultra.png","/Sys/Img/VBarA.png","/Sys/Img/VBarB.png","/Sys/Img/VBarC.png","/Sys/Img/Xylophone.png","/Sys/Img/bar_dark.png","/Sys/Img/ioio.png","/Sys/Snd/Bullet.mp3","/Sys/Snd/Explode.mp3","/Sys/Snd/Poing.ogg","/Sys/Snd/Trill.ogg"]
var player,lay2,img
//Called when application is started.
function OnStart()
{
    app.EnableBackKey(false);
    app.SetOrientation("Portrait");
    //Create a layout with objects vertically centered.
    var lay = app.CreateLayout( "absolute", "VCenter,FillXY" );    
 
    player = app.CreateMediaPlayer(); 
    player.SetOnReady(playerReady);
    //Create a text label and add it to layout.
    var lst = app.CreateList( arr );
    lst.SetOnTouch(lstOnTouch);
    lst.SetPosition(0,0.05);
    lay.AddChild( lst );
 
    //Add layout to app.    
    app.AddLayout( lay );
   
    lay2=app.CreateLayout("absolute","");
    lay2.SetBackColor("#ffdddddd");
    //property to simulate GetBackColor()
    lay2.backColor="#ffdddddd"
    img=app.CreateImage(null,0.95,0.85);
    img.SetOnTouchUp(imgOnTouch);
    lay2.AddChild(img);
    //seekbar to change background colour
    var skb=app.CreateSeekBar(0.95);
    skb.SetRange(15);
    skb.SetValue(13);
    skb.SetOnTouch(skbOnTouch);
    skb.SetPosition(0,0.85,0.95)
    lay2.AddChild(skb);
    lay2.SetVisibility("Hide");
    app.AddLayout(lay2);
}
 
function lstOnTouch(item)
{
    if(!app.FileExists(item)) return
    var three=item.slice(-3)
    if (three=="png" || three=="jpg")
    {
      var pic = app.CreateImage(item);
      img.Clear();
      img.DrawImage(pic,0,0,pic.GetWidth(),pic.GetHeight());
      lay2.Animate("SlideFromLeft");  
    }
    if (three=="mp3" || three=="ogg")
    {
        player.SetFile(item);
        player.SeekTo(0);
        player.Play();
    }
}
 
function imgOnTouch()
{
     lay2.Animate("SlideToLeft");
}
function skbOnTouch(value)
{
     var h = Math.round(value).toString(16);
     var col = "#ff"+h+h+h+h+h+h;
     if(lay2.backColor != col)
     {
        lay2.SetBackColor(col);
        lay2.backColor = col;
     }
}
function playerReady()
{
        player.SeekTo(0);
        player.Play();
}
 
function OnBack()
{
    if(lay2.GetVisibility()=="Show")
        lay2.Animate("SlideToLeft")
    else if(confirm("Exit")) app.Exit()
}