A flexible charting library for .NET

//============================================================================
//ZedGraph Class Library - A Flexible Line Graph/Bar Graph Library in C#
//Copyright � 2005  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
//=============================================================================

using System;
using System.Collections;
using System.Text;
using System.Drawing;
using System.Runtime.Serialization;
using System.Security.Permissions;

namespace ZedGraph
{
	/// <summary>
	/// The LinearScale class inherits from the <see cref="Scale" /> class, and implements
	/// the features specific to <see cref="AxisType.Linear" />.
	/// </summary>
	/// <remarks>
	/// LinearScale is the normal, default cartesian axis.
	/// </remarks>
	/// 
	/// <author> John Champion  </author>
	/// <version> $Revision: 1.9 $ $Date: 2006/06/24 20:26:43 $ </version>
	[Serializable]
	class LinearScale : Scale, ISerializable //, ICloneable
	{

	#region constructors

		/// <summary>
		/// Default constructor that defines the owner <see cref="Axis" />
		/// (containing object) for this new object.
		/// </summary>
		/// <param name="owner">The owner, or containing object, of this instance</param>
		public LinearScale( Axis owner )
			: base( owner )
		{
		}

		/// <summary>
		/// The Copy Constructor
		/// </summary>
		/// <param name="rhs">The <see cref="LinearScale" /> object from which to copy</param>
		/// <param name="owner">The <see cref="Axis" /> object that will own the
		/// new instance of <see cref="LinearScale" /></param>
		public LinearScale( Scale rhs, Axis owner )
			: base( rhs, owner )
		{
		}


		/// <summary>
		/// Create a new clone of the current item, with a new owner assignment
		/// </summary>
		/// <param name="owner">The new <see cref="Axis" /> instance that will be
		/// the owner of the new Scale</param>
		/// <returns>A new <see cref="Scale" /> clone.</returns>
		public override Scale Clone( Axis owner )
		{
			return new LinearScale( this, owner );
		}
	#endregion

	#region properties

		/// <summary>
		/// Return the <see cref="AxisType" /> for this <see cref="Scale" />, which is
		/// <see cref="AxisType.Linear" />.
		/// </summary>
		public override AxisType Type
		{
			get { return AxisType.Linear; }
		}

	#endregion

	#region methods

		/// <summary>
		/// Select a reasonable linear axis scale given a range of data values.
		/// </summary>
		/// <remarks>
		/// This method only applies to <see cref="AxisType.Linear"/> type axes, and it
		/// is called by the general <see cref="Scale.PickScale"/> method.  The scale range is chosen
		/// based on increments of 1, 2, or 5 (because they are even divisors of 10).  This
		/// method honors the <see cref="Scale.MinAuto"/>, <see cref="Scale.MaxAuto"/>,
		/// and <see cref="Scale.MajorStepAuto"/> autorange settings.
		/// In the event that any of the autorange settings are false, the
		/// corresponding <see cref="Scale.Min"/>, <see cref="Scale.Max"/>, or <see cref="Scale.MajorStep"/>
		/// setting is explicitly honored, and the remaining autorange settings (if any) will
		/// be calculated to accomodate the non-autoranged values.  The basic defaults for
		/// scale selection are defined using <see cref="Scale.Default.ZeroLever"/>,
		/// <see cref="Scale.Default.TargetXSteps"/>, and <see cref="Scale.Default.TargetYSteps"/>
		/// from the <see cref="Scale.Default"/> default class.
		/// <para>On Exit:</para>
		/// <para><see cref="Scale.Min"/> is set to scale minimum (if <see cref="Scale.MinAuto"/> = true)</para>
		/// <para><see cref="Scale.Max"/> is set to scale maximum (if <see cref="Scale.MaxAuto"/> = true)</para>
		/// <para><see cref="Scale.MajorStep"/> is set to scale step size (if <see cref="Scale.MajorStepAuto"/> = true)</para>
		/// <para><see cref="Scale.MinorStep"/> is set to scale minor step size (if <see cref="Scale.MinorStepAuto"/> = true)</para>
		/// <para><see cref="Scale.Mag"/> is set to a magnitude multiplier according to the data</para>
		/// <para><see cref="Scale.Format"/> is set to the display format for the values (this controls the
		/// number of decimal places, whether there are thousands separators, currency types, etc.)</para>
		/// </remarks>
		/// <param name="pane">A reference to the <see cref="GraphPane"/> object
		/// associated with this <see cref="Axis"/></param>
		/// <param name="g">
		/// A graphic device object to be drawn into.  This is normally e.Graphics from the
		/// PaintEventArgs argument to the Paint() method.
		/// </param>
		/// <param name="scaleFactor">
		/// The scaling factor to be used for rendering objects.  This is calculated and
		/// passed down by the parent <see cref="GraphPane"/> object using the
		/// <see cref="PaneBase.CalcScaleFactor"/> method, and is used to proportionally adjust
		/// font sizes, etc. according to the actual size of the graph.
		/// </param>
		/// <seealso cref="PickScale"/>
		/// <seealso cref="AxisType.Linear"/>
		override public void PickScale( GraphPane pane, Graphics g, float scaleFactor )
		{
			// call the base class first
			base.PickScale( pane, g, scaleFactor );

			// Test for trivial condition of range = 0 and pick a suitable default
			if ( _max - _min < 1.0e-30 )
			{
				if ( _maxAuto )
					_max = _max + 0.2 * ( _max == 0 ? 1.0 : Math.Abs( _max ) );
				if ( _minAuto )
					_min = _min - 0.2 * ( _min == 0 ? 1.0 : Math.Abs( _min ) );
			}

			// This is the zero-lever test.  If minVal is within the zero lever fraction
			// of the data range, then use zero.

			if ( _minAuto && _min > 0 &&
				_min / ( _max - _min ) < Default.ZeroLever )
				_min = 0;

			// Repeat the zero-lever test for cases where the maxVal is less than zero
			if ( _maxAuto && _max < 0 &&
				Math.Abs( _max / ( _max - _min ) ) <
				Default.ZeroLever )
				_max = 0;

			// Calculate the new step size
			if ( _majorStepAuto )
			{
				double targetSteps = ( _ownerAxis is XAxis ) ? Default.TargetXSteps : Default.TargetYSteps;

				// Calculate the step size based on target steps
				_majorStep = CalcStepSize( _max - _min, targetSteps );

				if ( _isPreventLabelOverlap )
				{
					// Calculate the maximum number of labels
					double maxLabels = (double) this.CalcMaxLabels( g, pane, scaleFactor );

					if ( maxLabels < ( _max - _min ) / _majorStep )
						_majorStep = CalcBoundedStepSize( _max - _min, maxLabels );
				}
			}

			// Calculate the new step size
			if ( _minorStepAuto )
				_minorStep = CalcStepSize( _majorStep,
					( _ownerAxis is XAxis ) ? Default.TargetMinorXSteps : Default.TargetMinorYSteps );

			// Calculate the scale minimum
			if ( _minAuto )
				_min = _min - MyMod( _min, _majorStep );

			// Calculate the scale maximum
			if ( _maxAuto )
				_max = MyMod( _max, _majorStep ) == 0.0 ? _max :
					_max + _majorStep - MyMod( _max, _majorStep );

			SetScaleMag( _min, _max, _majorStep );
		}


	#endregion

	#region Serialization
		/// <summary>
		/// Current schema value that defines the version of the serialized file
		/// </summary>
		public const int schema2 = 10;

		/// <summary>
		/// Constructor for deserializing objects
		/// </summary>
		/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data
		/// </param>
		/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data
		/// </param>
		protected LinearScale( SerializationInfo info, StreamingContext context ) : base( info, context )
		{
			// The schema value is just a file version parameter.  You can use it to make future versions
			// backwards compatible as new member variables are added to classes
			int sch = info.GetInt32( "schema2" );

		}
		/// <summary>
		/// Populates a <see cref="SerializationInfo"/> instance with the data needed to serialize the target object
		/// </summary>
		/// <param name="info">A <see cref="SerializationInfo"/> instance that defines the serialized data</param>
		/// <param name="context">A <see cref="StreamingContext"/> instance that contains the serialized data</param>
		[SecurityPermissionAttribute(SecurityAction.Demand,SerializationFormatter=true)]
		public override void GetObjectData( SerializationInfo info, StreamingContext context )
		{
			base.GetObjectData( info, context );
			info.AddValue( "schema2", schema2 );
		}
	#endregion

	}
}