/Main/src/DynamicDataDisplay/ViewportConstraints/ViewportConstraint.cs

 1using System;
 2using System.Collections.Generic;
 3using System.Linq;
 4using System.Text;
 5using System.Windows;
 6using Microsoft.Research.DynamicDataDisplay.Common;
 7
 8namespace Microsoft.Research.DynamicDataDisplay.ViewportConstraints
 9{
10	/// <summary>
11	/// Represents a base class for all constraints that are being applied to viewport's visible rect.
12	/// </summary>
13	public abstract class ViewportConstraint
14	{
15		/// <summary>
16		/// Applies the constraint.
17		/// </summary>
18		/// <param name="previousDataRect">Previous data rectangle.</param>
19		/// <param name="proposedDataRect">Proposed data rectangle.</param>
20		/// <param name="viewport">The viewport, to which current restriction is being applied.</param>
21		/// <returns>New changed visible rectangle.</returns>
22		public abstract DataRect Apply(DataRect previousDataRect, DataRect proposedDataRect, Viewport2D viewport);
23
24		/// <summary>
25		/// Raises the changed event.
26		/// </summary>
27		protected void RaiseChanged()
28		{
29			Changed.Raise(this);
30		}
31		/// <summary>
32		/// Occurs when constraint changes.
33		/// Causes update of <see cref="Viewport"/>'s Visible property.
34		/// </summary>
35		public event EventHandler Changed;
36	}
37}