【MQL】MTF_Bands（マルチタイムフレームボリンジャーバンド）

//+------------------------------------------------------------------+
//|                                                    MTF_Bands.mq4 |
//|                                  Copyright 2025, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"
#property strict

#property indicator_chart_window
#property indicator_buffers 3
#property indicator_color1 Magenta
#property indicator_color2 Magenta
#property indicator_color3 Magenta

//--- indicator parameters
input ENUM_TIMEFRAMES TimeFrame = PERIOD_CURRENT;   //　時間足
input int    InpBandsPeriod=20;                     // Bands Period
input int    InpBandsShift=0;                       // Bands Shift
input double InpBandsDeviations=2.0;                // Bands Deviations

//--- buffers
double ExtMovingBuffer[];
double ExtUpperBuffer[];
double ExtLowerBuffer[];

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
{
    //--- middle line
    SetIndexStyle(0,DRAW_LINE);
    SetIndexBuffer(0,ExtMovingBuffer);
    SetIndexShift(0,InpBandsShift);
    SetIndexLabel(0,"Bands SMA");
    ArraySetAsSeries(ExtMovingBuffer, true);

    //--- upper band
    SetIndexStyle(1,DRAW_LINE);
    SetIndexBuffer(1,ExtUpperBuffer);
    SetIndexShift(1,InpBandsShift);
    SetIndexLabel(1,"Bands Upper");
    ArraySetAsSeries(ExtUpperBuffer, true);

    //--- lower band
    SetIndexStyle(2,DRAW_LINE);
    SetIndexBuffer(2,ExtLowerBuffer);
    SetIndexShift(2,InpBandsShift);
    SetIndexLabel(2,"Bands Lower");
    ArraySetAsSeries(ExtLowerBuffer, true);

    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[])
{
    if (_Period > TimeFrame && TimeFrame != PERIOD_CURRENT) return -1;
    int limit = rates_total-prev_calculated-1;
    for (int i=limit; i>=0; i--)
    {
        int bar = iBarShift(NULL, TimeFrame, Time[i]);
        if (bar == -1) continue;
        ExtUpperBuffer[i] = iBands(NULL,TimeFrame,InpBandsPeriod,InpBandsDeviations,InpBandsShift,PRICE_CLOSE,MODE_UPPER,bar);
        ExtMovingBuffer[i] = iBands(NULL,TimeFrame,InpBandsPeriod,InpBandsDeviations,InpBandsShift,PRICE_CLOSE,MODE_MAIN,bar);
        ExtLowerBuffer[i] = iBands(NULL,TimeFrame,InpBandsPeriod,InpBandsDeviations,InpBandsShift,PRICE_CLOSE,MODE_LOWER,bar);
    }

    return(rates_total);
}