using System;

using System.Collections.Generic;

namespace EllipseTruncate {

	public class ActivePoint {

		public Point point;

		public ActivePoint(double x, double y) {

			point = new Point(x, y);

		}

	}

    public class MainWindow : Gtk.Window {

        static public void Main() {

        	Gtk.Application.Init();

        	MainWindow win = new MainWindow();

			win.Show();

			win.Maximize();

        	Gtk.Application.Run();

        }

		Point cursor;

		Point offset;

		ActivePoint point;

		ActiveAngleRange rangeAdd;

		ActiveAngleRange rangeXor;

		ActiveAngleRange rangeSub;

		List<activepoint> points = new List<activepoint>();</activepoint></activepoint>

		List<activeanglerange> ranges = new List<activeanglerange>();</activeanglerange></activeanglerange>

		ActivePoint ellipse0 = new ActivePoint(500.0, 500.0),

		            ellipse1 = new ActivePoint(600.0, 500.0),

		            ellipse2 = new ActivePoint(500.0, 450.0);

		ActivePoint bounds0 = new ActivePoint(450.0, 500.0),

		            bounds1 = new ActivePoint(500.0, 700.0),

		            bounds2 = new ActivePoint(600.0, 550.0);

		ActiveAngleRange rangeA = new ActiveAngleRange(new Point(150.0, 150.0), 50.0);

		ActiveAngleRange rangeB = new ActiveAngleRange(new Point(400.0, 150.0), 50.0);

		public MainWindow(): base(Gtk.WindowType.Toplevel) {

			Events = Gdk.EventMask.KeyPressMask

				   | Gdk.EventMask.KeyReleaseMask

			       | Gdk.EventMask.ButtonPressMask

			       | Gdk.EventMask.ButtonReleaseMask

			       | Gdk.EventMask.ButtonMotionMask

			       | Gdk.EventMask.PointerMotionMask;

			ExtensionEvents = Gdk.ExtensionMode.All;

			rangeA.b = rangeB.a;

			rangeB.b = rangeA.a;

			points.AddRange(new ActivePoint[] {ellipse0, ellipse1, ellipse2, bounds0, bounds1, bounds2});

			ranges.AddRange(new ActiveAngleRange[] {rangeA, rangeB});

        }

        private bool refreshOnIdle()

        	{ QueueDraw(); return false; }

        private void Refresh() {

        	QueueDraw(); //GLib.Idle.Add(refreshOnIdle);

        }

        protected override bool OnDeleteEvent(Gdk.Event e) {

			Gtk.Application.Quit();

			return false;

		}

		protected override bool OnExposeEvent(Gdk.EventExpose e) {

            Cairo.Context context = Gdk.CairoHelper.Create(e.Window);

        	context.Save();

        	context.SetSourceRGBA(1.0, 1.0, 1.0, 1.0);

        	context.Rectangle(0, 0, Allocation.Width, Allocation.Height);

        	context.Fill();

        	context.Restore();

        	context.Save();

			context.Antialias = Cairo.Antialias.Gray;

			foreach(ActivePoint p in points) {

        		context.Save();

				context.SetSourceRGBA(0.0, point == p ? 1.0 : 0.0, 1.0, 1.0);

				context.Arc(p.point.x, p.point.y, 5.0, 0, 2.0*Math.PI);

				context.Fill();

        		context.Restore();

			}

			{ // draw bounds

				Point p0 = bounds0.point, p1 = bounds1.point, p2 = bounds2.point;

        		context.Save();

				context.SetSourceRGBA(0.5, 0.5, 0.5, 0.2);

				context.LineWidth = 2.0;

				context.MoveTo(p0.x, p0.y);

				context.LineTo(p1.x, p1.y);

				context.LineTo(p1.x + p2.x - p0.x, p1.y + p2.y - p0.y);

				context.LineTo(p2.x, p2.y);

				context.ClosePath();

				context.Stroke();

        		context.Restore();

			}

			// draw ellipse

			Ellipse ellipse = new Ellipse(ellipse0.point, ellipse1.point, ellipse2.point);

			ellipse.drawFull(context);

			ellipse.drawTruncated(context, bounds0.point, bounds1.point, bounds2.point);

			// draw concentric grid

			ConcentricGrid cg = new ConcentricGrid(

				ellipse, 20.0, bounds0.point, bounds1.point, bounds2.point );

			cg.draw(context);

			// draw ranges

			foreach(ActiveAngleRange rl in ranges) {

				rl.draw(context);

				if ((cursor - rl.point).len() < 2.0*rl.radius || !rl.current.isEmpty()) {

					context.Save();

					context.SetSourceRGBA(0.0, 0.0, 0.0, 0.5);

					context.LineWidth = 1.0;

					context.MoveTo(rl.point.x, rl.point.y);

					context.LineTo(cursor.x, cursor.y);

					context.Stroke();

					context.Restore();

				}					

			}

        	context.Restore();

            context.Dispose();

			return false;

		}

		private void releaseButton() {

			if (rangeAdd != null) rangeAdd.add();

			if (rangeXor != null) rangeXor.xor();

			if (rangeSub != null) rangeSub.subtract();

			point = null;

			rangeAdd = null;

			rangeXor = null;

			rangeSub = null;

		}

		protected override bool OnButtonPressEvent(Gdk.EventButton e) {

			cursor = new Point(e.X, e.Y);

			releaseButton();

			ActivePoint ap = null;

			Point o = new Point();

		    foreach(ActivePoint p in points)

				if ((p.point - cursor).len() <= 5.0)

					{ o = p.point - cursor; ap = p; }

			ActiveAngleRange ar = null;

			uint a0 = 0;

		    foreach(ActiveAngleRange r in ranges)

				if ((r.point - cursor).len() < 2.0*r.radius)

					{ ar = r; a0 = AngleRange.toUIntDiscrete((cursor - r.point).atan()); }

			if (e.Button == 1) {

				if (ap != null) {

					point = ap;

					offset = o;

				} else

				if (ar != null) {

					ar.current = new AngleRange.Entry();

					ar.current.a0 = a0;

					rangeAdd = ar;

				}

			} else

			if (e.Button == 2) {

				if (ar != null) {

					ar.current = new AngleRange.Entry();

					ar.current.a0 = a0;

					rangeXor = ar;

				}

			} else

			if (e.Button == 3) {

				if (ar != null) {

					ar.current = new AngleRange.Entry();

					ar.current.a0 = a0;

					rangeSub = ar;

				}

			}

			Refresh();

			return false;

		}

		protected override bool OnButtonReleaseEvent(Gdk.EventButton e) {

			cursor = new Point(e.X, e.Y);

			releaseButton();

			Refresh();

			return false;

		}

		protected override bool OnMotionNotifyEvent(Gdk.EventMotion e) {

			cursor = new Point(e.X, e.Y);

			if (point != null) point.point = cursor + offset;

			if (rangeAdd != null)

				rangeAdd.current.a1 = AngleRange.toUIntDiscrete((cursor - rangeAdd.point).atan());

			if (rangeXor != null)

				rangeXor.current.a1 = AngleRange.toUIntDiscrete((cursor - rangeXor.point).atan());

			if (rangeSub != null)

				rangeSub.current.a1 = AngleRange.toUIntDiscrete((cursor - rangeSub.point).atan());

			Refresh();

			return false;

		}

    }

}