SSL channel chart

//+------------------------------------------------------------------+
//|                                            SSL channel chart.mq4 |
//|                                                           mladen |
//|                                                                  |
//| initial SSL for metatrader developed by Kalenzo                  |
//+------------------------------------------------------------------+
#property copyright "copyleft mladen"
#property link      "mladenfx@gmail.com"

#property indicator_chart_window
#property indicator_buffers 4
#property indicator_color1 Red
#property indicator_color2 Green
#property indicator_color3 OrangeRed
#property indicator_color4 Lime
#property indicator_width1 2
#property indicator_width2 2

//
//
//
//
//

extern int  Lb            = 10;
extern bool alertsOn      = false;
extern bool alertsMessage = true;
extern bool alertsSound   = false;
extern bool alertsEmail   = false;
extern bool showArrows    = false;

double ssld[];
double sslu[];
double sslad[];
double sslau[];
double Hlv[];


//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

int init()
{
   IndicatorBuffers(5);
   SetIndexBuffer(0,ssld);  SetIndexDrawBegin(0,Lb+1);
   SetIndexBuffer(1,sslu);  SetIndexDrawBegin(0,Lb+1);
   SetIndexBuffer(2,sslad); SetIndexDrawBegin(0,Lb+1); SetIndexStyle(2,DRAW_ARROW); SetIndexArrow(2,234);
   SetIndexBuffer(3,sslau); SetIndexDrawBegin(0,Lb+1); SetIndexStyle(3,DRAW_ARROW); SetIndexArrow(3,233);
   SetIndexBuffer(4,Hlv);
   return(0);
}

//
//
//
//
//
int start()
{
   int counted_bars=IndicatorCounted();
   int i,limit;

   if(counted_bars<0) return(-1);
   if(counted_bars>0) counted_bars--;
           limit=Bars-counted_bars;

   //
   //
   //
   //
   //

   for(i=limit;i>=0;i--)
   {
      Hlv[i] = Hlv[i+1];
         if(Close[i]>iMA(Symbol(),0,Lb,0,MODE_SMA,PRICE_HIGH,i+1)) Hlv[i] =  1;
         if(Close[i]<iMA(Symbol(),0,Lb,0,MODE_SMA,PRICE_LOW,i+1))  Hlv[i] = -1;
      
         if(Hlv[i] == -1)
            {
               ssld[i] = iMA(Symbol(),0,Lb,0,MODE_SMA,PRICE_HIGH,i+1);
               sslu[i] = iMA(Symbol(),0,Lb,0,MODE_SMA,PRICE_LOW ,i+1);
            }               
         else
            {
               ssld[i] = iMA(Symbol(),0,Lb,0,MODE_SMA,PRICE_LOW ,i+1);
               sslu[i] = iMA(Symbol(),0,Lb,0,MODE_SMA,PRICE_HIGH,i+1);
            } 

      //
      //
      //
      //
      //
      
      sslau[i] = EMPTY_VALUE;
      sslad[i] = EMPTY_VALUE;
         if (showArrows)
         {
            if (Hlv[i]!=Hlv[i+1])
            if (Hlv[i]==1)
                     sslau[i] = ssld[i]-iATR(NULL,0,15,i)/2.0;
            else     sslad[i] = ssld[i]+iATR(NULL,0,15,i)/2.0;
         }         
   }
   
   //
   //
   //
   //
   //
   
   if (alertsOn)
      if (Hlv[0] != Hlv[1])
      if (Hlv[0] == 1)
            doAlert("up");
      else  doAlert("down");       
      
   return(0);
}


//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
//
//
//
//
//

void doAlert(string doWhat)
{
   static string   previousAlert="nothing";
   static datetime previousTime;
   string message;
   
      if (previousAlert != doWhat || previousTime != Time[0]) {
          previousAlert  = doWhat;
          previousTime   = Time[0];

          //
          //
          //
          //
          //

          message =  StringConcatenate(Symbol()," at ",TimeToStr(TimeLocal(),TIME_SECONDS)," SSL trend changed to ",doWhat);
             if (alertsMessage) Alert(message);
             if (alertsEmail)   SendMail(StringConcatenate(Symbol(),"SSL "),message);
             if (alertsSound)   PlaySound("alert2.wav");
      }
}