int  iAlligator(
   string              symbol,            // symbol name
   ENUM_TIMEFRAMES     period,            // period
   int                 jaw_period,        // period for the calculation of jaws
   int                 jaw_shift,         // horizontal shift of jaws
   int                 teeth_period,      // period for the calculation of teeth
   int                 teeth_shift,       // horizontal shift of teeth
   int                 lips_period,       // period for the calculation of lips
   int                 lips_shift,        // horizontal shift of lips
   ENUM_MA_METHOD      ma_method,         // type of smoothing
   ENUM_APPLIED_PRICE  applied_price      // type of price or handle
   );

//+------------------------------------------------------------------+
//|                                              Demo_iAlligator.mq5 |
//|                        Copyright 2011, MetaQuotes Software Corp. |
//|                                              https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2000-2024, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property description "The indicator demonstrates how to obtain data"
#property description "of indicator buffers for the iAlligator technical indicator."
#property description "A symbol and timeframe used for calculation of the indicator,"
#property description "are set by the symbol and period parameters."
#property description "The method of creation of the handle is set through the 'type' parameter (function type)."
#property description "All the other parameters are similar to the standard Alligator."

#property indicator_chart_window
#property indicator_buffers 3
#property indicator_plots   3
//--- plot Jaws
#property indicator_label1  "Jaws"
#property indicator_type1   DRAW_LINE
#property indicator_color1  clrBlue
#property indicator_style1  STYLE_SOLID
#property indicator_width1  1
//--- plot Teeth
#property indicator_label2  "Teeth"
#property indicator_type2   DRAW_LINE
#property indicator_color2  clrRed
#property indicator_style2  STYLE_SOLID
#property indicator_width2  1
//--- plot Lips
#property indicator_label3  "Lips"
#property indicator_type3   DRAW_LINE
#property indicator_color3  clrLime
#property indicator_style3  STYLE_SOLID
#property indicator_width3  1
//+------------------------------------------------------------------+
//| Enumeration of the methods of handle creation                    |
//+------------------------------------------------------------------+
enum Creation
  {
   Call_iAlligator,        // use iAlligator
   Call_IndicatorCreate    // use IndicatorCreate
  };
//--- input parameters
input Creation             type=Call_iAlligator;   // type of the function
input string               symbol=" ";             // symbol
input ENUM_TIMEFRAMES      period=PERIOD_CURRENT;  // timeframe
input int                  jaw_period=13;          // period of the Jaw line
input int                  jaw_shift=8;            // shift of the Jaw line
input int                  teeth_period=8;         // period of the Teeth line
input int                  teeth_shift=5;          // shift of the Teeth line
input int                  lips_period=5;          // period of the Lips line
input int                  lips_shift=3;           // shift of the Lips line
input ENUM_MA_METHOD       MA_method=MODE_SMMA;    // method of averaging of the Alligator lines
input ENUM_APPLIED_PRICE   applied_price=PRICE_MEDIAN;// type of price used for calculation of Alligator
//--- indicator buffers
double         JawsBuffer[];
double         TeethBuffer[];
double         LipsBuffer[];
//--- variable for storing the handle of the iAlligator indicator
int    handle;
//--- variable for storing
string name=symbol;
//--- name of the indicator on a chart
string short_name;
//--- we will keep the number of values in the Alligator indicator
int    bars_calculated=0;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- assignment of arrays to indicator buffers
   SetIndexBuffer(0,JawsBuffer,INDICATOR_DATA);
   SetIndexBuffer(1,TeethBuffer,INDICATOR_DATA);
   SetIndexBuffer(2,LipsBuffer,INDICATOR_DATA);
//--- set shift of each line
   PlotIndexSetInteger(0,PLOT_SHIFT,jaw_shift);
   PlotIndexSetInteger(1,PLOT_SHIFT,teeth_shift);
   PlotIndexSetInteger(2,PLOT_SHIFT,lips_shift);
//--- determine the symbol the indicator is drawn for
   name=symbol;
//--- delete spaces to the right and to the left
   StringTrimRight(name);
   StringTrimLeft(name);
//--- if it results in zero length of the 'name' string
   if(StringLen(name)==0)
     {
      //--- take the symbol of the chart the indicator is attached to
      name=_Symbol;
     }
//--- create handle of the indicator
   if(type==Call_iAlligator)
      handle=iAlligator(name,period,jaw_period,jaw_shift,teeth_period,
                        teeth_shift,lips_period,lips_shift,MA_method,applied_price);
   else
     {
      //--- fill the structure with parameters of the indicator
      MqlParam pars[8];
     //--- periods and shifts of the Alligator lines
      pars[0].type=TYPE_INT;
      pars[0].integer_value=jaw_period;
      pars[1].type=TYPE_INT;
      pars[1].integer_value=jaw_shift;
      pars[2].type=TYPE_INT;
      pars[2].integer_value=teeth_period;
      pars[3].type=TYPE_INT;
      pars[3].integer_value=teeth_shift;
      pars[4].type=TYPE_INT;
      pars[4].integer_value=lips_period;
      pars[5].type=TYPE_INT;
      pars[5].integer_value=lips_shift;
//--- type of smoothing
      pars[6].type=TYPE_INT;
      pars[6].integer_value=MA_method;
//--- type of price
      pars[7].type=TYPE_INT;
      pars[7].integer_value=applied_price;
//--- create handle
      handle=IndicatorCreate(name,period,IND_ALLIGATOR,8,pars);
     }
//--- if the handle is not created
   if(handle==INVALID_HANDLE)
     {
      //--- tell about the failure and output the error code
      PrintFormat("Failed to create handle of the iAlligator indicator for the symbol %s/%s, error code %d",
                  name,
                  EnumToString(period),
                  GetLastError());
      //--- the indicator is stopped early
      return(INIT_FAILED);
     }
//--- show the symbol/timeframe the Alligator indicator is calculated for
   short_name=StringFormat("iAlligator(%s/%s, %d,%d,%d,%d,%d,%d)",name,EnumToString(period),
                           jaw_period,jaw_shift,teeth_period,teeth_shift,lips_period,lips_shift);
   IndicatorSetString(INDICATOR_SHORTNAME,short_name);
//--- normal initialization of the indicator
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {
//--- number of values copied from the iAlligator indicator
   int values_to_copy;
//--- determine the number of values calculated in the indicator
   int calculated=BarsCalculated(handle);
   if(calculated<=0)
     {
      PrintFormat("BarsCalculated() returned %d, error code %d",calculated,GetLastError());
      return(0);
     }
//--- if it is the first start of calculation of the indicator or if the number of values in the iAlligator indicator changed
//---or if it is necessary to calculated the indicator for two or more bars (it means something has changed in the price history)
   if(prev_calculated==0 || calculated!=bars_calculated || rates_total>prev_calculated+1)
     {
      //--- if the JawsBuffer array is greater than the number of values in the iAlligator indicator for symbol/period, then we don't copy everything
      //--- otherwise, we copy less than the size of indicator buffers
      if(calculated>rates_total) values_to_copy=rates_total;
      else                       values_to_copy=calculated;
     }
   else
     {
      //--- it means that it's not the first time of the indicator calculation, and since the last call of OnCalculate()
      //--- for calculation not more than one bar is added
      values_to_copy=(rates_total-prev_calculated)+1;
     }
//--- fill the arrays with values of the Alligator indicator
//--- if FillArraysFromBuffer returns false, it means the information is nor ready yet, quit operation
   if(!FillArraysFromBuffers(JawsBuffer,jaw_shift,TeethBuffer,teeth_shift,LipsBuffer,lips_shift,handle,values_to_copy)) return(0);
//--- form the message
   string comm=StringFormat("%s ==>  Updated value in the indicator %s: %d",
                            TimeToString(TimeCurrent(),TIME_DATE|TIME_SECONDS),
                            short_name,
                            values_to_copy);
//--- display the service message on the chart
   Comment(comm);
//--- memorize the number of values in the Alligator indicator
   bars_calculated=calculated;
//--- return the prev_calculated value for the next call
   return(rates_total);
  }
//+------------------------------------------------------------------+
//| Filling indicator buffers from the iAlligator indicator          |
//+------------------------------------------------------------------+
bool FillArraysFromBuffers(double &jaws_buffer[],  // indicator buffer for the Jaw line
                           int j_shift,            // shift of the Jaw line
                           double &teeth_buffer[], // indicator buffer for the Teeth line
                           int t_shift,            // shift of the Teeth line
                           double &lips_buffer[],  // indicator buffer for the Lips line
                           int l_shift,            // shift of the Lips line
                           int ind_handle,         // handle of the iAlligator indicator
                           int amount              // number of copied values
                           )
  {
//--- reset error code
   ResetLastError();
//--- fill a part of the JawsBuffer array with values from the indicator buffer that has 0 index
   if(CopyBuffer(ind_handle,0,-j_shift,amount,jaws_buffer)<0)
     {
      //--- if the copying fails, tell the error code
      PrintFormat("Failed to copy data from the iAlligator indicator, error code %d",GetLastError());
      //--- quit with zero result - it means that the indicator is considered as not calculated
      return(false);
     }

//--- fill a part of the TeethBuffer array with values from the indicator buffer that has index 1
   if(CopyBuffer(ind_handle,1,-t_shift,amount,teeth_buffer)<0)
     {
      //--- if the copying fails, tell the error code
      PrintFormat("Failed to copy data from the iAlligator indicator, error code %d",GetLastError());
      //--- quit with zero result - it means that the indicator is considered as not calculated
      return(false);
     }

//--- fill a part of the LipsBuffer array with values from the indicator buffer that has index 2
   if(CopyBuffer(ind_handle,2,-l_shift,amount,lips_buffer)<0)
     {
      //--- if the copying fails, tell the error code
      PrintFormat("Failed to copy data from the iAlligator indicator, error code %d",GetLastError());
      //--- quit with zero result - it means that the indicator is considered as not calculated
      return(false);
     }
//--- everything is fine
   return(true);
  }
//+------------------------------------------------------------------+
//| Indicator deinitialization function                              |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
   if(handle!=INVALID_HANDLE)
      IndicatorRelease(handle);
//--- clear the chart after deleting the indicator
   Comment("");
  }