ChartSizeEventArgs

 using cAlgo.API;
 namespace cAlgo
 {
     // This example shows how to use the Chart ChartSizeEventArgs
     [Indicator(IsOverlay = true, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
     public class ChartSizeEventArgsSample : Indicator
     {
         protected override void Initialize()
         {
             Chart.SizeChanged += Chart_SizeChanged;
         }
         private void Chart_SizeChanged(ChartSizeEventArgs obj)
         {
             Chart.DrawStaticText("size", "Size Changed", VerticalAlignment.Top, HorizontalAlignment.Right, Color.Red);
         }
         public override void Calculate(int index)
         {
         }
     }
 }

 import clr
 clr.AddReference("cAlgo.API")
 from cAlgo.API import *
 class Test():    
     def initialize(self):
         api.Chart.SizeChanged += self.on_chart_size_changed
     def on_chart_size_changed(self, args):
         api.Chart.DrawStaticText("size", "Size Changed", VerticalAlignment.Top, HorizontalAlignment.Right, Color.Red)