【MQL4】マーチンゲールで連敗した場合の必要証拠金を事前に一覧表示するシミュレーター・インジケーターの作り方

//+------------------------------------------------------------------+
//|                            MartingaleMarginSimulatorIndicator.mq4 |
//|                     Copyright 2026, FX-EA System Project Creator |
//|                        https://creator.fx-ea-system-project.com/ |
//+------------------------------------------------------------------+
#property copyright "Copyright 2026, FX-EA System Project Creator"
#property link      "https://creator.fx-ea-system-project.com/"
#property version   "1.00"
#property strict
#property indicator_chart_window
#property indicator_buffers 0

#define LABEL_NAME "MartingaleMarginHeadline"

input double InpInitialLots     = 0.01;  //連敗0回のときのロット
input double InpLotMultiplier   = 2.0;   //1連敗ごとのロット倍率
input int    InpMaxLevelsToShow = 10;    //一覧に表示する最大連敗回数

void UpdatePanel()
  {
   double marginPerLot = MarketInfo(_Symbol, MODE_MARGINREQUIRED);
   double maxLot        = MarketInfo(_Symbol, MODE_MAXLOT);
   double freeMargin    = AccountFreeMargin();

   double cumulative = 0;
   int    limitLevel  = -1;
   string table = "";

   for(int i = 0; i <= InpMaxLevelsToShow; i++)
     {
      double lots = InpInitialLots * MathPow(InpLotMultiplier, i);
      if(lots > maxLot)
         lots = maxLot;

      double required = marginPerLot * lots;
      cumulative += required;

      if(limitLevel == -1 && cumulative > freeMargin)
         limitLevel = i;

      table += StringFormat("連敗%d回: %sロット 必要証拠金(積算)%s円\n",
                             i, DoubleToString(lots, 2), DoubleToString(cumulative, 0));
     }

   Comment(table);

   string headline;
   color  headlineColor;

   if(limitLevel == -1)
     {
      headline = StringFormat("連敗%d回まではフリーマージン(%s円)の範囲内です",
                               InpMaxLevelsToShow, DoubleToString(freeMargin, 0));
      headlineColor = clrLime;
     }
   else
     {
      headline = StringFormat("連敗%d回目でフリーマージン(%s円)を超えます",
                               limitLevel, DoubleToString(freeMargin, 0));
      headlineColor = clrRed;
     }

   ObjectSetText(LABEL_NAME, headline, 11, "Arial", headlineColor);
  }

int OnInit()
  {
   ObjectCreate(0, LABEL_NAME, OBJ_LABEL, 0, 0, 0);
   ObjectSetInteger(0, LABEL_NAME, OBJPROP_CORNER, CORNER_LEFT_UPPER);
   ObjectSetInteger(0, LABEL_NAME, OBJPROP_XDISTANCE, 10);
   ObjectSetInteger(0, LABEL_NAME, OBJPROP_YDISTANCE, 20);
   EventSetTimer(5);
   UpdatePanel();
   return(INIT_SUCCEEDED);
  }

void OnDeinit(const int reason)
  {
   EventKillTimer();
   ObjectDelete(0, LABEL_NAME);
   Comment("");
  }

void OnTimer()
  {
   UpdatePanel();
  }

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[])
  {
   UpdatePanel();
   return(rates_total);
  }