/Main/src/DynamicDataDisplay/Charts/MarkerElementPointGraph.cs

using System.Collections.Generic;

using System.Windows;

using System.Windows.Media;

using Microsoft.Research.DynamicDataDisplay.DataSources;

using Microsoft.Research.DynamicDataDisplay.PointMarkers;

using Microsoft.Research.DynamicDataDisplay.Common;

using System.Windows.Controls;



namespace Microsoft.Research.DynamicDataDisplay

{

	public class ElementMarkerPointsGraph : PointsGraphBase

	{

		/// <summary>List with created but unused markers</summary>

		private readonly List<UIElement> unused = new List<UIElement>();



		/// <summary>Initializes a new instance of the <see cref="MarkerPointsGraph"/> class.</summary>

		public ElementMarkerPointsGraph()

		{

			ManualTranslate = true; // We'll handle translation by ourselves

		}



		/// <summary>Initializes a new instance of the <see cref="MarkerPointsGraph"/> class.</summary>

		/// <param name="dataSource">The data source.</param>

		public ElementMarkerPointsGraph(IPointDataSource dataSource)

			: this()

		{

			DataSource = dataSource;

		}



		Grid grid;

		Canvas canvas;



		protected override void OnPlotterAttached(Plotter plotter)

		{

			base.OnPlotterAttached(plotter);



			grid = new Grid();

			canvas = new Canvas { ClipToBounds = true };

			grid.Children.Add(canvas);



			Plotter2D.CentralGrid.Children.Add(grid);

		}



		protected override void OnPlotterDetaching(Plotter plotter)

		{

			Plotter2D.CentralGrid.Children.Remove(grid);

			grid = null;

			canvas = null;



			base.OnPlotterDetaching(plotter);

		}



		protected override void OnDataChanged()

		{

			//			if (canvas != null)

			//			{

			//                foreach(UIElement child in canvas.Children)

			//                    unused.Add(child);

			//				canvas.Children.Clear();

			//			}

			// todo почему так?

			base.OnDataChanged();

		}



		public ElementPointMarker Marker

		{

			get { return (ElementPointMarker)GetValue(MarkerProperty); }

			set { SetValue(MarkerProperty, value); }

		}



		public static readonly DependencyProperty MarkerProperty =

			DependencyProperty.Register(

			  "Marker",

			  typeof(ElementPointMarker),

			  typeof(ElementMarkerPointsGraph),

			  new FrameworkPropertyMetadata { DefaultValue = null, AffectsRender = true }

				  );



		protected override void OnRenderCore(DrawingContext dc, RenderState state)

		{

			if (Marker == null)

				return;



			if (DataSource == null) // No data is specified

			{

				if (canvas != null)

				{

					foreach (UIElement child in canvas.Children)

						unused.Add(child);

					canvas.Children.Clear();

				}

			}

			else // There is some data

			{

		  

				int index = 0;

				var transform = GetTransform();

				using (IPointEnumerator enumerator = DataSource.GetEnumerator(GetContext()))

				{

					Point point = new Point();



					DataRect bounds = DataRect.Empty;



					while (enumerator.MoveNext())

					{

						enumerator.GetCurrent(ref point);

						enumerator.ApplyMappings(Marker);



						if (index >= canvas.Children.Count)

						{

							UIElement newMarker;

							if (unused.Count > 0)

							{

								newMarker = unused[unused.Count - 1];

								unused.RemoveAt(unused.Count - 1);

							}

							else

								newMarker = Marker.CreateMarker();

							canvas.Children.Add(newMarker);

						}



						Marker.SetMarkerProperties(canvas.Children[index]);

						bounds.Union(point);

						Point screenPoint = point.DataToScreen(transform);

						Marker.SetPosition(canvas.Children[index], screenPoint);

						index++;

					}



					Viewport2D.SetContentBounds(this, bounds);



					while (index < canvas.Children.Count)

					{

						unused.Add(canvas.Children[index]);

						canvas.Children.RemoveAt(index);

					}

				}

			}

		}

	}

}