Initial Commit

ViewportRestrictions/ViewportRestriction.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows;
+using Microsoft.Research.DynamicDataDisplay.Common;
+
+namespace Microsoft.Research.DynamicDataDisplay.ViewportRestrictions
+{
+	/// <summary>
+	/// Represents a base class for all restrictions that are being applied to viewport's visible rect.
+	/// </summary>
+	public abstract class ViewportRestriction
+	{
+		#region IViewportRestriction Members
+
+		/// <summary>
+		/// Applies the restriction.
+		/// </summary>
+		/// <param name="previousDataRect">Previous data rectangle.</param>
+		/// <param name="proposedDataRect">Proposed data rectangle.</param>
+		/// <param name="viewport">The viewport, to which current restriction is being applied.</param>
+		/// <returns>New changed visible rectangle.</returns>
+		public abstract DataRect Apply(DataRect previousDataRect, DataRect proposedDataRect, Viewport2D viewport);
+
+		/// <summary>
+		/// Raises the changed event.
+		/// </summary>
+		protected void RaiseChanged()
+		{
+			Changed.Raise(this);
+		}
+		/// <summary>
+		/// Occurs when restriction changes.
+		/// Causes update of <see cref="Viewport"/>'s Visible property.
+		/// </summary>
+		public event EventHandler Changed;
+
+		#endregion
+	}
+}