//+------------------------------------------------------------------+
//|                                      Demo_IndicatorSetDouble.mq5 |
//|                        Copyright 2012, MetaQuotes Software Corp. |
//|                                              http://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2012, MetaQuotes Software Corp."
#property link      "http://www.mql5.com"
#property version   "1.00"
#property indicator_separate_window
//--- set the maximum and minimum values for the indicator window
#property indicator_minimum  0
#property indicator_maximum  100
//--- display three horizontal levels in a separate indicator window
#property indicator_level1 25
#property indicator_level2 50
#property indicator_level3 75
//--- set thickness of horizontal levels
#property indicator_levelwidth 1
//--- set style of horizontal levels
#property indicator_levelstyle STYLE_DOT
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
//--- set descriptions of horizontal levels 
   IndicatorSetString(INDICATOR_LEVELTEXT,0,"First Level (index 0)");
   IndicatorSetString(INDICATOR_LEVELTEXT,1,"Second Level (index 1)");
   IndicatorSetString(INDICATOR_LEVELTEXT,2,"Third Level (index 2)");
//--- set the short name for indicator
   IndicatorSetString(INDICATOR_SHORTNAME,"IndicatorSetDouble() Demo");
//--- set color for each level
   IndicatorSetInteger(INDICATOR_LEVELCOLOR,0,clrBlue);
   IndicatorSetInteger(INDICATOR_LEVELCOLOR,1,clrGreen);
   IndicatorSetInteger(INDICATOR_LEVELCOLOR,2,clrRed);
//---
   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[])
  {
   static int tick_counter=0;
   static double level1=25,level2=50,level3=75;
   static double max=100,min=0, shift=100;
//--- calculate ticks
   tick_counter++;
//--- turn levels upside down on every 10th tick
   if(tick_counter%10==0)
     {
      //--- invert sign for the level values
      level1=-level1;
      level2=-level2;
      level3=-level3;
      //--- invert sign for the maximum and minimum values
      max-=shift;
      min-=shift;
      //--- invert the shift value
      shift=-shift;
      //--- set new level values
      IndicatorSetDouble(INDICATOR_LEVELVALUE,0,level1);
      IndicatorSetDouble(INDICATOR_LEVELVALUE,1,level2);
      IndicatorSetDouble(INDICATOR_LEVELVALUE,2,level3);
      //--- set new values of maximum and minimum in the indicator window
      Print("Set up max = ",max,",   min = ",min);
      IndicatorSetDouble(INDICATOR_MAXIMUM,max);
      IndicatorSetDouble(INDICATOR_MINIMUM,min);
     }
//--- return value of prev_calculated for next call
   return(rates_total);
  }
//+------------------------------------------------------------------+