//============================================================================
//ZedGraph Class Library - A Flexible Line Graph/Bar Graph Library in C#
//Copyright � 2004 John Champion
//
//This library is free software; you can redistribute it and/or
//modify it under the terms of the GNU Lesser General Public
//License as published by the Free Software Foundation; either
//version 2.1 of the License, or (at your option) any later version.
//
//This library is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
//Lesser General Public License for more details.
//
//You should have received a copy of the GNU Lesser General Public
//License along with this library; if not, write to the Free Software
//Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//=============================================================================
#region Using directives
using System;
using System.Collections.Generic;
using System.Text;
#endregion
namespace ZedGraph
{
/// <summary>
/// A LIFO stack of prior <see cref="ZoomState"/> objects, used to allow zooming out to prior
/// states (of scale range settings).
/// </summary>
/// <author> John Champion </author>
/// <version> $Revision: 3.1 $ $Date: 2006/06/24 20:26:44 $ </version>
public class ZoomStateStack : List<ZoomState>, ICloneable
{
/// <summary>
/// Default Constructor
/// </summary>
public ZoomStateStack()
{
}
/// <summary>
/// The Copy Constructor
/// </summary>
/// <param name="rhs">The <see cref="ZoomStateStack"/> object from which to copy</param>
public ZoomStateStack( ZoomStateStack rhs )
{
foreach ( ZoomState state in rhs )
{
Add( new ZoomState( state ) );
}
}
/// <summary>
/// Implement the <see cref="ICloneable" /> interface in a typesafe manner by just
/// calling the typed version of <see cref="Clone" />
/// </summary>
/// <returns>A deep copy of this object</returns>
object ICloneable.Clone()
{
return this.Clone();
}
/// <summary>
/// Typesafe, deep-copy clone method.
/// </summary>
/// <returns>A new, independent copy of this class</returns>
public ZoomStateStack Clone()
{
return new ZoomStateStack( this );
}
/// <summary>
/// Public readonly property that indicates if the stack is empty
/// </summary>
/// <value>true for an empty stack, false otherwise</value>
public bool IsEmpty
{
get { return this.Count == 0; }
}
/// <summary>
/// Add the scale range information from the specified <see cref="GraphPane"/> object as a
/// new <see cref="ZoomState"/> entry on the stack.
/// </summary>
/// <param name="pane">The <see cref="GraphPane"/> object from which the scale range
/// information should be copied.</param>
/// <param name="type">A <see cref="ZoomState.StateType"/> enumeration that indicates whether this
/// state is the result of a zoom or pan operation.</param>
/// <returns>The resultant <see cref="ZoomState"/> object that was pushed on the stack.</returns>
public ZoomState Push( GraphPane pane, ZoomState.StateType type )
{
ZoomState state = new ZoomState( pane, type );
this.Add( state );
return state;
}
/// <summary>
/// Add the scale range information from the specified <see cref="ZoomState"/> object as a
/// new <see cref="ZoomState"/> entry on the stack.
/// </summary>
/// <param name="state">The <see cref="ZoomState"/> object to be placed on the stack.</param>
/// <returns>The <see cref="ZoomState"/> object (same as the <see paramref="state"/>
/// parameter).</returns>
public ZoomState Push( ZoomState state )
{
this.Add( state );
return state;
}
/// <summary>
/// Pop a <see cref="ZoomState"/> entry from the top of the stack, and apply the properties
/// to the specified <see cref="GraphPane"/> object.
/// </summary>
/// <param name="pane">The <see cref="GraphPane"/> object to which the scale range
/// information should be copied.</param>
/// <returns>The <see cref="ZoomState"/> object that was "popped" from the stack and applied
/// to the specified <see cref="GraphPane"/>. null if no <see cref="ZoomState"/> was
/// available (the stack was empty).</returns>
public ZoomState Pop( GraphPane pane )
{
if ( !this.IsEmpty )
{
ZoomState state = (ZoomState) this[ this.Count - 1 ];
this.RemoveAt( this.Count - 1 );
state.ApplyState( pane );
return state;
}
else
return null;
}
/// <summary>
/// Pop the <see cref="ZoomState"/> entry from the bottom of the stack, and apply the properties
/// to the specified <see cref="GraphPane"/> object. Clear the stack completely.
/// </summary>
/// <param name="pane">The <see cref="GraphPane"/> object to which the scale range
/// information should be copied.</param>
/// <returns>The <see cref="ZoomState"/> object at the bottom of the stack that was applied
/// to the specified <see cref="GraphPane"/>. null if no <see cref="ZoomState"/> was
/// available (the stack was empty).</returns>
public ZoomState PopAll( GraphPane pane )
{
if ( !this.IsEmpty )
{
ZoomState state = (ZoomState) this[ 0 ];
this.Clear();
state.ApplyState( pane );
return state;
}
else
return null;
}
/// <summary>
/// Gets a reference to the <see cref="ZoomState"/> object at the top of the stack,
/// without actually removing it from the stack.
/// </summary>
/// <value>A <see cref="ZoomState"/> object reference, or null if the stack is empty.</value>
public ZoomState Top
{
get
{
if ( !this.IsEmpty )
return (ZoomState) this[ this.Count - 1 ];
else
return null;
}
}
}
}