//+------------------------------------------------------------------+ 
//|                                          Keltner_Channel_HTF.mq5 | 
//|                               Copyright © 2013, Nikolay Kositsin | 
//|                              Khabarovsk,   farria@mail.redcom.ru | 
//+------------------------------------------------------------------+ 
#property copyright "Copyright © 2013, Nikolay Kositsin"
#property link "farria@mail.redcom.ru"
//--- Indicator version
#property version   "1.00"
#property description "Keltner Channel with a preset timeframe specified in input parameters"
//--- drawing the indicator in the main window
#property indicator_chart_window
//---- number of indicator buffers is 3
#property indicator_buffers 3 
//---- three plots are used
#property indicator_plots   3
//+----------------------------------------------+
//|  declaring constants                         |
//+----------------------------------------------+
#define RESET 0                          // A constant for returning the indicator recalculation command to the terminal
#define INDICATOR_NAME "Keltner Channel" // A constant for the indicator name
#define SIZE 1                           // A constant for the number of calls of the CountIndicator function in the code
//+----------------------------------------------+
//|  Indicator 1 drawing parameters              |
//+----------------------------------------------+
//--- drawing indicator 1 as a line
#property indicator_type1   DRAW_LINE
//--- yellow color is used as the color of the indicator line
#property indicator_color1 clrYellow
//---- the indicator line is a continuous curve
#property indicator_style1  STYLE_SOLID
//--- indicator 1 line width is equal to 2
#property indicator_width1  2
//--- displaying the indicator label
#property indicator_label1  INDICATOR_NAME+"Up"
//+----------------------------------------------+
//|  Indicator 2 drawing parameters              |
//+----------------------------------------------+
//--- drawing indicator 2 as a line
#property indicator_type2   DRAW_LINE
//--- use gray color for the indicator line
#property indicator_color2 clrGray
//---- the indicator line is a continuous curve
#property indicator_style2  STYLE_SOLID
//--- indicator 2 line width is equal to 2
#property indicator_width2  2
//--- displaying the indicator label
#property indicator_label2  INDICATOR_NAME+"Middle"
//+----------------------------------------------+
//|  Indicator 3 drawing parameters              |
//+----------------------------------------------+
//--- drawing indicator 3 as a line
#property indicator_type3   DRAW_LINE
//--- Pink color is used for indicator line
#property indicator_color3 clrMagenta
//---- the indicator line is a continuous curve
#property indicator_style3  STYLE_SOLID
//---- indicator 3 line width is equal to 4
#property indicator_width3  4
//--- displaying the indicator label
#property indicator_label3  INDICATOR_NAME+"Down"
//+----------------------------------------------+
//|  declaration of enumerations                 |
//+----------------------------------------------+
enum Applied_price_      // type of constant
  {
   PRICE_CLOSE_ = 1,     // Close
   PRICE_OPEN_,          // Open
   PRICE_HIGH_,          // High
   PRICE_LOW_,           // Low
   PRICE_MEDIAN_,        // Median Price (HL/2)
   PRICE_TYPICAL_,       // Typical Price (HLC/3)
   PRICE_WEIGHTED_,      // Weighted Close (HLCC/4)
   PRICE_SIMPL_,         // Simple Price (OC/2)
   PRICE_QUARTER_,       // Quarted Price (HLOC/4) 
   PRICE_TRENDFOLLOW0_,  // TrendFollow_1 Price 
   PRICE_TRENDFOLLOW1_,  // TrendFollow_2 Price 
   PRICE_DEMARK_         // Demark Price
  };
//+----------------------------------------------+
//| Indicator input parameters                   |
//+----------------------------------------------+
input ENUM_TIMEFRAMES TimeFrame=PERIOD_H4;   // Indicator chart period
//---
input int KeltnerPeriod=20;                  // Period of averaging
input ENUM_MA_METHOD MA_Method_=MODE_SMA;    // Method of averaging
input double Ratio = 1.0;                    // Expansion ratio
input Applied_price_ IPC=PRICE_CLOSE_;       // Price constant
input int Shift=0;                           // Horizontal shift of the indicator in bars
//--- declaration of dynamic arrays that
//--- will be used as indicator buffers
double Ind1Buffer[];
double Ind2Buffer[];
double Ind3Buffer[];
//--- declaration of integer variables for the start of data calculation
int min_rates_total;
//--- declaration of integer variables for the indicators handles
int Ind_Handle;
//+------------------------------------------------------------------+
//|  Getting a timeframe as a line                                   |
//+------------------------------------------------------------------+
string GetStringTimeframe(ENUM_TIMEFRAMES timeframe)
  {return(StringSubstr(EnumToString(timeframe),7,-1));}
//+------------------------------------------------------------------+    
//| Custom indicator initialization function                         | 
//+------------------------------------------------------------------+  
int OnInit()
  {
//--- Checking correctness of the chart periods
   if(!TimeFramesCheck(INDICATOR_NAME,TimeFrame)) return(INIT_FAILED);
//--- initialization of variables 
   min_rates_total=2;
//--- getting the handle of the Keltner_Channel indicator
   Ind_Handle=iCustom(Symbol(),TimeFrame,"Keltner_Channel",KeltnerPeriod,MA_Method_,Ratio,IPC);
   if(Ind_Handle==INVALID_HANDLE)
     {
      Print(" Failed to get the handle of Keltner_Channel");
      return(INIT_FAILED);
     }
//--- Initialize indicator buffers
   IndInit(0,Ind1Buffer,0.0,min_rates_total,Shift);
   IndInit(1,Ind2Buffer,0.0,min_rates_total,Shift);
   IndInit(2,Ind3Buffer,0.0,min_rates_total,Shift);
//--- creation of the name to be displayed in a separate sub-window and in a pop up help
   string shortname;
   StringConcatenate(shortname,INDICATOR_NAME,"(",KeltnerPeriod,", ",
                     EnumToString(MA_Method_),", ",DoubleToString(Ratio,2),", ",EnumToString(IPC),")");
//---
   IndicatorSetString(INDICATOR_SHORTNAME,shortname);
//--- determining the accuracy of the indicator values
   IndicatorSetInteger(INDICATOR_DIGITS,_Digits);
//--- initialization end
   return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+  
//| Custom iteration function                                        | 
//+------------------------------------------------------------------+  
int OnCalculate(const int rates_total,    // number of bars in history at the current tick
                const int prev_calculated,// amount of history in bars at the previous tick
                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[])
  {
//--- checking if the number of bars is enough for the calculation
   if(rates_total<min_rates_total) return(RESET);
   if(BarsCalculated(Ind_Handle)<Bars(Symbol(),TimeFrame)) return(prev_calculated);
//--- indexing elements in arrays as in timeseries  
   ArraySetAsSeries(time,true);
//---
   if(!CountIndicator(0,NULL,TimeFrame,Ind_Handle,0,Ind1Buffer,1,Ind2Buffer,2,Ind3Buffer,
      time,rates_total,prev_calculated,min_rates_total)) return(RESET);
//---     
   return(rates_total);
  }
//---
//+------------------------------------------------------------------+
//| Indicator buffer initialization                                  |
//+------------------------------------------------------------------+    
void IndInit(int Number,double &Buffer[],double Empty_Value,int Draw_Begin,int nShift)
  {
//--- set dynamic array as an indicator buffer
   SetIndexBuffer(Number,Buffer,INDICATOR_DATA);
//--- shifting the start of drawing of the indicator
   PlotIndexSetInteger(Number,PLOT_DRAW_BEGIN,Draw_Begin);
//--- setting the indicator values that won't be visible on a chart
   PlotIndexSetDouble(Number,PLOT_EMPTY_VALUE,Empty_Value);
//---- shifting the indicator 2 horizontally by Shift
   PlotIndexSetInteger(Number,PLOT_SHIFT,nShift);
//--- indexing elements in the buffer as in timeseries
   ArraySetAsSeries(Buffer,true);
//---
  }
//+------------------------------------------------------------------+
//| CountIndicator                                                   |
//+------------------------------------------------------------------+
bool CountIndicator(uint     Numb,            // The number of the CountLine function in the list in the indicator code (starting number - 0)
                    string   Symb,            // Chart symbol
                    ENUM_TIMEFRAMES TFrame,   // Chart period
                    int      IndHandle,       // The handle of the processed indicator
                    uint     BuffNumb1,       // The number of the buffer of the processed indicator 1
                    double&  IndBuf1[],       // Receiving buffer of the indicator 1
                    uint     BuffNumb2,       // The number of the buffer of the processed indicator 2
                    double&  IndBuf2[],       // Receiving buffer of the indicator 2
                    uint     BuffNumb3,       // The number of the buffer of the processed indicator 3
                    double&  IndBuf3[],       // Receiving buffer of the indicator 3
                    const datetime& iTime[],  // Timeseries of time
                    const int Rates_Total,    // Amount of history in bars on the current tick
                    const int Prev_Calculated,// amount of history in bars at the previous tick
                    const int Min_Rates_Total)// minimum amount of history in bars for calculation
  {
//---
   static int LastCountBar[SIZE];
   datetime IndTime[1];
   int limit;
//--- calculations of the necessary amount of data to be copied
//--- and the 'limit' starting index for the bars recalculation loop
   if(Prev_Calculated>Rates_Total || Prev_Calculated<=0)// Checking for the first start of the indicator calculation
     {
      limit=Rates_Total-Min_Rates_Total-1; // Starting index for calculation of all bars
      LastCountBar[Numb]=limit;
     }
   else limit=LastCountBar[Numb]+Rates_Total-Prev_Calculated; // Starting index for calculation of new bars 
//--- main indicator calculation loop
   for(int bar=limit; bar>=0 && !IsStopped(); bar--)
     {
      //---- Copy new data to the IndTime array
      if(CopyTime(Symbol(),TFrame,iTime[bar],1,IndTime)<=0) return(RESET);

      if(iTime[bar]>=IndTime[0] && iTime[bar+1]<IndTime[0])
        {
         LastCountBar[Numb]=bar;
         double Arr[1];

         //--- copy newly appeared data in the arrays
         if(CopyBuffer(IndHandle,BuffNumb1,iTime[bar],1,Arr)<=0) return(RESET); IndBuf1[bar]=Arr[0];
         if(CopyBuffer(IndHandle,BuffNumb2,iTime[bar],1,Arr)<=0) return(RESET); IndBuf2[bar]=Arr[0];
         if(CopyBuffer(IndHandle,BuffNumb3,iTime[bar],1,Arr)<=0) return(RESET); IndBuf3[bar]=Arr[0];
        }
      else
        {
         IndBuf1[bar]=IndBuf1[bar+1];
         IndBuf2[bar]=IndBuf2[bar+1];
         IndBuf3[bar]=IndBuf3[bar+1];
        }
     }
//---     
   return(true);
  }
//+------------------------------------------------------------------+
//| TimeFramesCheck()                                                |
//+------------------------------------------------------------------+    
bool TimeFramesCheck(string IndName,
                     ENUM_TIMEFRAMES TFrame) // Indicator chart period
  {
//--- checking correctness of the chart periods
   if(TFrame<Period() && TFrame!=PERIOD_CURRENT)
     {
      Print("Chart period for the "+IndName+" indicator cannot be less than the period of the current chart!");
      Print ("You must change the indicator input parameters!");
      return(RESET);
     }
//---
   return(true);
  }
//+------------------------------------------------------------------+