====== imgTouch_OnTouch ======

The **imgTouch_OnTouch** function allows add custom LED array touch function. 

The **ev** parameter is an event object which has 3 fields: X, Y in range 0..1 and action ("Up", "Down", "Move").

Default touch handler works as below:
<code javascript>
function ( ev )
{
  //app.Debug( "x=" + ev.X + " y=" + ev.Y );
  
  //Calculate which LED we are touching.
  var x = Math.floor(  ev.X * 5 );
  var y = Math.floor(  ev.Y * 5 );
  
  //Keep x and y between 0 and 4.
  x = Math.min( Math.max(x,0), 4 );
  y = Math.min( Math.max(y,0), 4 );
  //app.Debug( "LED = " + x + "," + y );
  
  if( ev.action=="Move" )
    _this.SetLED( x, y );
  else if( ev.action=="Up" )
    _this.SendLEDStates();
}
</code>

It could be changed to different behavior.

====Example - Custom imgTouch_OnTouch handler====

This script has custom touch handler toggling LEDs without swipe. Only one LED is toggled at "Down" action.

<code javascript>
// Load the MicroBit plugin.
app.LoadPlugin( "MicroBit" );

// Called when application is started.
function OnStart()
{
  // Lock screen orientation to Portrait.
  app.SetOrientation( "Portrait" );

  // Create our main layout.
  lay = app.CreateLayout( "Linear", "VCenter,FillXY" );
  lay.SetBackColor( "#222222" );

  // Create the Microbit plugin.
  microbit = app.CreateMicroBit();

  // Create MicroBit controller.
  ctrl = microbit.CreateController( 0.9 );
  
  // Adds custom imgTouch_OnTouch handler
  ctrl.imgTouch_OnTouch = imgTouch_OnTouch;
  
  lay.AddChild( ctrl );

  //Create horizontal layout for buttons
  layButs = app.CreateLayout( "Linear", "Horizontal" );
  layButs.SetMargins( 0,0.05,0,0 );
  lay.AddChild( layButs );

  //Create a bluetooth connect button.
  btnConnect = app.CreateButton( "[fa-bluetooth-b]", 0.25, 0.15, "FontAwesome" );
  btnConnect.SetTextSize( 66 );
  btnConnect.SetTextColor( "#3366ff" );
  btnConnect.SetOnTouch( txtBT_OnTouchDown );
  layButs.AddChild( btnConnect );

  //Create clear button.
  btnClear= app.CreateButton( "[fa-times]", 0.25, 0.15, "FontAwesome" );
  btnClear.SetTextSize( 66 );
  btnClear.SetTextColor( "#ff4444" );
  btnClear.SetOnTouch( btnClear_OnClick );
  layButs.AddChild( btnClear );

  //Add main layout to the app.
  app.AddLayout( lay );
}

// Handle Bluetooth button press.
function txtBT_OnTouchDown()
{
  microbit.Scan();
}

// Handle 'clear' button press.
function btnClear_OnClick()
{
  ctrl.Clear();
}

// Handle toggling LEDs without swipe. Only one LED is toggled at "Down" action.
function imgTouch_OnTouch( ev ) {
  //app.Debug( ev.X+':'+ev.Y+':'+ev.action );
  
  //Calculate which LED we are touching.
  var x = Math.floor(  ev.X * 5 );
  var y = Math.floor(  ev.Y * 5 );
  
  //Keep x and y between 0 and 4.
  x = Math.min( Math.max(x,0), 4 );
  y = Math.min( Math.max(y,0), 4 );
  //app.Debug( "LED = " + x + "," + y );
  
  if ( ev.action=="Down" ) {
    ctrl.ToggleLED( x, y );
  } 
}
</code>