using Gtk;
using Cairo;
using System;
class SharpApp : Window
{ public SharpApp() : base("Ґрадієнти")
  { SetDefaultSize(340, 390);
    SetPosition(WindowPosition.Center);
    DeleteEvent += delegate { Application.Quit(); };
    DrawingArea darea = new DrawingArea();
    darea.ExposeEvent += OnExpose;
    Add(darea);
    ShowAll();
  }

  void OnExpose(object sender, ExposeEventArgs args)
  { DrawingArea area = (DrawingArea) sender;
    Cairo.Context cr =  Gdk.CairoHelper.Create(area.GdkWindow);
    LinearGradient lg1 = new LinearGradient(0.0, 0.0, 350.0, 350.0);
    int count = 1;
    for (double j=0.1; j<1.0; j+= 0.1)
    { if (Convert.ToBoolean(count % 2)) {lg1.AddColorStop(j, new Color(0,1,0,1));}
      else                              {lg1.AddColorStop(j, new Color(1,0,0,1));}
      count++;
    }
    cr.Rectangle(20, 20, 300, 100);
    cr.SetSource(lg1);
    cr.Fill();
    LinearGradient lg2 = new LinearGradient(0.0, 0.0, 350.0, 0);
    count = 1;
    for (double i=0.05; i<0.95; i+= 0.1)
    { if (Convert.ToBoolean(count % 2)) {lg2.AddColorStop(i, new Color(0,0,0,1));}
      else                              {lg2.AddColorStop(i, new Color(0,1,0,1));}
      count++;
    }
    cr.Rectangle(20, 140, 300, 100);
    cr.SetSource(lg2);
    cr.Fill();
    LinearGradient lg3 = new LinearGradient(20.0, 260.0,  20.0, 360.0);
    lg3.AddColorStop(0.1, new Color(1,0,0,1));
    lg3.AddColorStop(0.5, new Color(1,1,0,1));
    lg3.AddColorStop(0.9, new Color(1,0,0,1));
    cr.Rectangle(20, 260, 300, 100);
    cr.SetSource(lg3);
    cr.Fill();
    lg1.Dispose();
    lg2.Dispose();
    lg3.Dispose();        
    ((IDisposable) cr.GetTarget()).Dispose();                                      
    ((IDisposable) cr).Dispose();
  }

  public static void Main()
  { Application.Init();
    new SharpApp();
    Application.Run();
  }
}