Refactor IndicatorExtensions: Remove unused methods and optimize price retrieval

lib/trends/ema/Ema.Quantower.Tests.cs

@@ -19,12 +19,12 @@ public class EmaIndicatorTests
     }
 
     [Fact]
-    public void EmaIndicator_MinHistoryDepths_EqualsPeriod()
+    public void EmaIndicator_MinHistoryDepths_EqualsZero()
     {
         var indicator = new EmaIndicator { Period = 20 };
 
-        Assert.Equal(20, indicator.MinHistoryDepths);
-        Assert.Equal(20, ((IWatchlistIndicator)indicator).MinHistoryDepths);
+        Assert.Equal(0, EmaIndicator.MinHistoryDepths);
+        Assert.Equal(0, ((IWatchlistIndicator)indicator).MinHistoryDepths);
     }
 
     [Fact]
@@ -164,6 +164,6 @@ public class EmaIndicatorTests
 
         indicator.Period = 20;
         Assert.Equal(20, indicator.Period);
-        Assert.Equal(20, indicator.MinHistoryDepths);
+        Assert.Equal(0, EmaIndicator.MinHistoryDepths);
     }
 }

lib/trends/ema/Ema.Quantower.cs

@@ -1,8 +1,10 @@
 using System.Drawing;
+using System.Runtime.CompilerServices;
 using TradingPlatform.BusinessLayer;
 
 namespace QuanTAlib;
 
+[SkipLocalsInit]
 public class EmaIndicator : Indicator, IWatchlistIndicator
 {
     [InputParameter("Period", sortIndex: 1, 1, 1000, 1, 0)]
@@ -17,9 +19,9 @@ public class EmaIndicator : Indicator, IWatchlistIndicator
     private Ema? ma;
     protected LineSeries? Series;
     protected string? SourceName;
-    private int _warmupBarIndex = -1;
+    private Func<IHistoryItem, double>? _priceSelector;
 
-    public int MinHistoryDepths => Period;
+    public static int MinHistoryDepths => 0;
     int IWatchlistIndicator.MinHistoryDepths => MinHistoryDepths;
 
     public override string ShortName => $"EMA {Period}:{SourceName}";
@@ -39,27 +41,15 @@ public class EmaIndicator : Indicator, IWatchlistIndicator
     {
         ma = new Ema(Period);
         SourceName = Source.ToString();
-        _warmupBarIndex = -1;  // Reset warmup tracking when period changes
+        _priceSelector = Source.GetPriceSelector();
         base.OnInit();
     }
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
     protected override void OnUpdate(UpdateArgs args)
     {
-        TValue input = this.GetInputValue(args, Source);
-        bool isNew = args.Reason == UpdateReason.NewBar || args.Reason == UpdateReason.HistoricalBar;
-        TValue result = ma!.Update(input, isNew);
-        Series!.SetValue(result.Value);
-        Series!.SetMarker(0, Color.Transparent); //OnPaintChart draws the line, hidden here
-
-        // Track when IsHot becomes true for the first time
-        if (_warmupBarIndex < 0 && ma!.IsHot)
-            _warmupBarIndex = Count;
-    }
-
-    public override void OnPaintChart(PaintChartEventArgs args)
-    {
-        base.OnPaintChart(args);
-        int warmupPeriod = _warmupBarIndex > 0 ? _warmupBarIndex : Count;
-        this.PaintSmoothCurve(args, Series!, warmupPeriod, showColdValues: ShowColdValues, tension: 0.2);
+        var item = HistoricalData[Count - 1, SeekOriginHistory.Begin];
+        TValue result = ma!.Update(new TValue(item.TimeLeft.Ticks, _priceSelector!(item)), isNew: args.IsNewBar());
+        Series!.SetValue(result.Value, ma.IsHot, ShowColdValues);
     }
 }