OHLC Channel

ÿþ//+------------------------------------------------------------------+

//|                                                 OHLC Channel.mq5 |

//|                              Copyright © 2018, Vladimir Karputov |

//|                                           http://wmua.ru/slesar/ |

//+------------------------------------------------------------------+

#property copyright "Copyright © 2018, Vladimir Karputov"

#property link      "http://wmua.ru/slesar/"

#property version   "1.000"

#property indicator_chart_window

#property indicator_buffers 2

#property indicator_plots   2

//--- plot High

#property indicator_label1  "Up"

#property indicator_type1   DRAW_LINE

#property indicator_color1  clrChartreuse

#property indicator_style1  STYLE_SOLID

#property indicator_width1  2

//--- plot Low

#property indicator_label2  "Down"

#property indicator_type2   DRAW_LINE

#property indicator_color2  clrDeepPink

#property indicator_style2  STYLE_SOLID

#property indicator_width2  2

//---

enum ENUM_PRICE

  {

   open_price     = 0,  // Open

   high_price     = 1,  // High

   low_price      = 2,  // Low

   close_price    = 3,  // Close

  };

//--- input parameters

input ENUM_PRICE  InpUp    = high_price;

input ENUM_PRICE  InpDown  = low_price;

//--- indicator buffers

double            HighBuffer[];

double            LowBuffer[];

//+------------------------------------------------------------------+

//| Custom indicator initialization function                         |

//+------------------------------------------------------------------+

int OnInit()

  {

//--- indicator buffers mapping

   SetIndexBuffer(0,HighBuffer,INDICATOR_DATA);

   SetIndexBuffer(1,LowBuffer,INDICATOR_DATA);

//---

   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[])

  {

//--- by default in the MQL5 indicator on the chart: 

//    left bar                | right bar

//    D'1980.07.19 12:30:27'  | D'2018.07.19 12:30:27'

   int limit=prev_calculated-1;

   if(prev_calculated==0)

      limit=0;

   for(int i=limit;i<rates_total;i++)

     {

      switch(InpUp)

        {

         case open_price:

            HighBuffer[i]=open[i];

            break;

         case high_price:

            HighBuffer[i]=high[i];

            break;

         case low_price:

            HighBuffer[i]=low[i];

            break;

         case close_price:

            HighBuffer[i]=close[i];

            break;

        }

      switch(InpDown)

        {

         case open_price:

            LowBuffer[i]=open[i];

            break;

         case high_price:

            LowBuffer[i]=high[i];

            break;

         case low_price:

            LowBuffer[i]=low[i];

            break;

         case close_price:

            LowBuffer[i]=close[i];

            break;

        }

     }

//--- return value of prev_calculated for next call

   return(rates_total);

  }

//+------------------------------------------------------------------+