Initial Commit

Viewport2dDeferredPanningProxy.cs

@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows;
+using Microsoft.Research.DynamicDataDisplay.Common;
+
+namespace Microsoft.Research.DynamicDataDisplay
+{
+	internal sealed class Viewport2dDeferredPanningProxy : Viewport2D
+	{
+		private Viewport2D viewport;
+		internal Viewport2dDeferredPanningProxy(Viewport2D viewport)
+			: base(viewport.HostElement, viewport.Plotter2D)
+		{
+			viewport.PropertyChanged += viewport_PropertyChanged;
+			viewport.PanningStateChanged += viewport_PanningStateChanged;
+			this.viewport = viewport;
+		}
+
+		DataRect prevVisible;
+
+		private void viewport_PanningStateChanged(object sender, ValueChangedEventArgs<Viewport2DPanningState> e)
+		{
+			if (e.CurrentValue == Viewport2DPanningState.Panning && e.PreviousValue == Viewport2DPanningState.NotPanning)
+			{
+				prevVisible = Visible;
+			}
+			else if (e.CurrentValue == Viewport2DPanningState.NotPanning && e.PreviousValue == Viewport2DPanningState.Panning)
+			{
+				notMineEvent = true;
+				try
+				{
+					Visible = viewport.Visible;
+				}
+				finally { notMineEvent = false; }
+			}
+		}
+
+		protected override DataRect CoerceVisible(DataRect newVisible)
+		{
+			if (viewport == null)
+				return new DataRect(0, 0, 1, 1);
+
+			if (viewport.PanningState == Viewport2DPanningState.Panning)
+				return prevVisible;
+
+			return base.CoerceVisible(newVisible);
+		}
+
+		private bool notMineEvent = false;
+		private void viewport_PropertyChanged(object sender, ExtendedPropertyChangedEventArgs e)
+		{
+			notMineEvent = true;
+			try
+			{
+				RaisePropertyChanged(e);
+			}
+			finally
+			{
+				notMineEvent = false;
+			}
+		}
+
+		public override CoordinateTransform Transform
+		{
+			get
+			{
+				if (viewport.PanningState == Viewport2DPanningState.Panning)
+					return viewport.Transform.WithRects(prevVisible, viewport.Output);
+				return viewport.Transform;
+			}
+			set
+			{
+				base.Transform = value;
+			}
+		}
+
+		protected override void RaisePropertyChanged(ExtendedPropertyChangedEventArgs args)
+		{
+			if (args.PropertyName == "Visible")
+			{
+				if (notMineEvent)
+				{
+					if (viewport.PanningState == Viewport2DPanningState.NotPanning)
+					{
+						base.RaisePropertyChanged(args);
+					}
+					else
+					{
+						// do nothing
+					}
+				}
+			}
+			else
+			{
+				base.RaisePropertyChanged(args);
+			}
+		}
+	}
+}