//+-------------------------------------------------------------------+
//|                                                    Bandswidth.mq4 |
//|                                         by Linuxser for Forex TSD |
//|                                                                   |
//| John Bollinger original formula is:                               |
//| (Upper BB - Lower BB)/middle BB                                   |
//+-------------------------------------------------------------------+
#property copyright ""
#property link      ""

#property indicator_separate_window
#property indicator_buffers 1
#property indicator_color1 Yellow


//---- input parameters
extern int BBPeriod=20;
extern int StdDeviation=2;
input int    TriggerCandle 	= 1;
input bool   EnableNativeAlerts = true;
input bool   EnableSoundAlerts  = true;
input bool   EnableEmailAlerts  = true;
input bool   EnablePushAlerts  = true;
input string AlertEmailSubject  = "";
input string AlertText  	= "";
input string SoundFileName	= "alert.wav";

datetime LastAlertTime = D'01.01.1970';
int LastAlertDirection = 0;
//---- buffers
double BLGBuffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
   string short_name;
//---- indicator line
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,BLGBuffer);
//---- name for DataWindow and indicator subwindow label
   short_name="Bandswidth("+BBPeriod+","+StdDeviation+")";
   IndicatorShortName(short_name);
   SetIndexLabel(0,short_name);
//----
   SetIndexDrawBegin(0,BBPeriod);
//----
if (((TriggerCandle > 0) && (Time[0] > LastAlertTime)) || (TriggerCandle == 0))
{
	string Text;
	// Bellow 15 Alert
	if (((BLGBuffer[TriggerCandle] < 15) && (BLGBuffer[TriggerCandle+ 1] <= 0)) && ((TriggerCandle > 0) || ((TriggerCandle == 0) && (LastAlertDirection != 1))))
	{
		Text = AlertText + "BLGBuffer: " + Symbol() + " - " + EnumToString((ENUM_TIMEFRAMES)Period()) + " - Bellow 15.";
		if (EnableNativeAlerts) Alert(Text);
		if (EnableEmailAlerts) SendMail(AlertEmailSubject + "BLGBuffer Alert", Text);
		if (EnableSoundAlerts) PlaySound(SoundFileName);
		if (EnablePushAlerts) SendNotification(Text);
		LastAlertTime = Time[0];
		LastAlertDirection = 1;
	}
	// Bellow 8 Alert
	if (((BLGBuffer[TriggerCandle] < 8) && (BLGBuffer[TriggerCandle+ 1] >= 0)) && ((TriggerCandle > 0) || ((TriggerCandle == 0) && (LastAlertDirection != -1))))
	{
		Text = AlertText + "BLGBuffer: " + Symbol() + " - " + EnumToString((ENUM_TIMEFRAMES)Period()) + " - Below 8.";
		if (EnableNativeAlerts) Alert(Text);
		if (EnableEmailAlerts) SendMail(AlertEmailSubject + "BLGBuffer Alert", Text);
		if (EnableSoundAlerts) PlaySound(SoundFileName);
		if (EnablePushAlerts) SendNotification(Text);
		LastAlertTime = Time[0];
		LastAlertDirection = -1;
	}
}
   return(0);
  }
//+------------------------------------------------------------------+
//| Momentum                                                         |
//+------------------------------------------------------------------+
int start()
  {
   int i,counted_bars=IndicatorCounted();
//----
   if(Bars<=BBPeriod) return(0);
//---- initial zero
   if(counted_bars<1)
      for(i=1;i<=BBPeriod;i++) BLGBuffer[Bars-i]=0.0;
//----
   i=Bars-BBPeriod-1;
   if(counted_bars>=BBPeriod) i=Bars-counted_bars-1;
   while(i>=0)
     {
      BLGBuffer[i]= (iBands(NULL,0,BBPeriod,StdDeviation,0,PRICE_CLOSE,MODE_UPPER,i) - iBands(NULL,0,BBPeriod,StdDeviation,0,PRICE_CLOSE,MODE_LOWER,i))
      /iMA(NULL,0,BBPeriod,0,MODE_SMA,PRICE_CLOSE,i);
      i--;
     }
   return(0);
  }
//+------------------------------------------------------------------+