LabelPointPlot.cs

/*
NPlot - A charting library for .NET

LabelPointPlot.cs
Copyright (C) 2003
Matt Howlett

Redistribution and use of NPlot or parts there-of in source and
binary forms, with or without modification, are permitted provided
that the following conditions are met:

1. Re-distributions in source form must retain at the head of each
   source file the above copyright notice, this list of conditions
   and the following disclaimer.

2. Any product ("the product") that makes use NPlot or parts 
   there-of must either:
  
    (a) allow any user of the product to obtain a complete machine-
        readable copy of the corresponding source code for the 
        product and the version of NPlot used for a charge no more
        than your cost of physically performing source distribution,
	on a medium customarily used for software interchange, or:

    (b) reproduce the following text in the documentation, about 
        box or other materials intended to be read by human users
        of the product that is provided to every human user of the
        product: 
   
              "This product includes software developed as 
              part of the NPlot library project available 
              from: http://www.nplot.com/" 

        The words "This product" may optionally be replace with 
        the actual name of the product.

------------------------------------------------------------------------

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

*/

using System;
using System.Drawing;
using System.Data;

namespace NPlot
{

	/// <summary>
	/// Encapsulates functionality
	/// </summary>
	public class LabelPointPlot : PointPlot, ISequencePlot
	{

		/// <summary>
		/// This class us used in conjunction with SequenceAdapter to interpret data
		/// specified to the TextPlot class.
		/// </summary>
		private class TextDataAdapter
		{

			private object data_;
			private object dataSource_;
			private string dataMember_;

			public TextDataAdapter( object dataSource, string dataMember, object data )
			{
				this.data_ = data;
				this.dataSource_ = dataSource;
				this.dataMember_ = dataMember;
			}

			public string this[int i]
			{
				get
				{

					// this is inefficient [could set up delegates in constructor].

					if (data_ is string[])
					{
						return ((string[])data_)[i];
					}
					
					if (data_ is string)
					{
						if (dataSource_ == null)
						{
							throw new NPlotException( "Error: DataSource null" );
						}

						System.Data.DataRowCollection rows;

						if ( dataSource_ is System.Data.DataSet )
						{
							if (dataMember_ != null)
							{
								// TODO error check
								rows = ((DataTable)((DataSet)dataSource_).Tables[dataMember_]).Rows;
							}
							else
							{
								// TODO error check
								rows = ((DataTable)((DataSet)dataSource_).Tables[0]).Rows;
							}
						}

						else if (dataSource_ is System.Data.DataTable )
						{
							rows = ((DataTable)dataSource_).Rows;
						}

						else
						{
							throw new NPlotException ( "not implemented yet" );
						}

						return (string)((System.Data.DataRow)(rows[i]))[(string)data_];
					}

					if (data_ is System.Collections.ArrayList)
					{
						object dataPoint = ((System.Collections.ArrayList)data_)[i];
						if (dataPoint is string)
							return (string)dataPoint;
						throw new NPlotException( "TextDataAdapter: data not in recognised format" );
					}
					
					if (data_ == null)
					{
						return "text";
					}

					throw new NPlotException( "Text data not of recognised type" );
				}
			}


			public int Count
			{
				get
				{
					// this is inefficient [could set up delegates in constructor].

					if (data_ == null)
					{
						return 0;
					}
					if (data_ is string[])
					{
						return ((string[])data_).Length;
					}
					if (data_ is System.Collections.ArrayList)
					{
						return ((System.Collections.ArrayList)data_).Count;
					}
					throw new NPlotException( "Text data not in correct format" );
				}
			}

		}


		/// <summary>
		/// Enumeration of all label positions relative to a point.
		/// </summary>
		public enum LabelPositions
		{
			/// <summary>
			/// Above the point
			/// </summary>
			Above,
			/// <summary>
			/// Below the point
			/// </summary>
			Below,
			/// <summary>
			/// To the left of the point
			/// </summary>
			Left,
			/// <summary>
			/// To the right of the point
			/// </summary>
			Right
		}


		/// <summary>
		/// Default Constructor
		/// </summary>
		public LabelPointPlot()
		{
		}


		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="marker">The marker type to use for this plot.</param>
		public LabelPointPlot( Marker marker ) 
			: base( marker )
		{
		}

		
		/// <summary>
		/// The position of the text label in relation to the point.
		/// </summary>
		public LabelPositions LabelTextPosition
		{
			get
			{
				return labelTextPosition_;
			}
			set
			{
				labelTextPosition_ = value;
			}
		}
		private LabelPositions labelTextPosition_ = LabelPositions.Above;


		/// <summary>
		/// The text datasource to attach to each point.
		/// </summary>
		public object TextData
		{
			get
			{
				return textData_;
			}
			set
			{
				textData_ = value;
			}
		}
		object textData_;


		/// <summary>
		/// The Font used to write text.
		/// </summary>
		public Font Font
		{
			get
			{
				return font_;
			}
			set
			{
				font_ = value;
			}
		}
		private Font font_ = new Font( "Arial", 8.0f );


		/// <summary>
		/// Draws the plot on a GDI+ surface against the provided x and y axes.
		/// </summary>
		/// <param name="g">The GDI+ surface on which to draw.</param>
		/// <param name="xAxis">The X-Axis to draw against.</param>
		/// <param name="yAxis">The Y-Axis to draw against.</param>
		public override void Draw( Graphics g, PhysicalAxis xAxis, PhysicalAxis yAxis )
		{
			SequenceAdapter data = 
				new SequenceAdapter( this.DataSource, this.DataMember, this.OrdinateData, this.AbscissaData );

			TextDataAdapter textData =
				new TextDataAdapter( this.DataSource, this.DataMember, this.TextData );

			// first plot the marker
		    // we can do this cast, since the constructor accepts only this type!
			for (int i=0; i<data.Count; ++i)
			{
				try
				{
					PointD pt = data[i];
					if ( !Double.IsNaN(pt.X) && !Double.IsNaN(pt.Y) )
					{
						PointF xPos = xAxis.WorldToPhysical( pt.X, false);
						PointF yPos = yAxis.WorldToPhysical( pt.Y, false);
						Marker.Draw( g, (int)xPos.X, (int)yPos.Y );
						if ( textData[i] != "" )
						{
							SizeF size = g.MeasureString( textData[i], this.Font );
							switch (labelTextPosition_)
							{
								case LabelPositions.Above:
									g.DrawString( textData[i], font_, Brushes.Black, new PointF(xPos.X-size.Width/2,yPos.Y-size.Height-Marker.Size*2/3));
									break;
								case LabelPositions.Below:
									g.DrawString( textData[i], font_, Brushes.Black, new PointF(xPos.X-size.Width/2,yPos.Y+Marker.Size*2/3));
									break;
								case LabelPositions.Left:
									g.DrawString( textData[i], font_, Brushes.Black, new PointF(xPos.X-size.Width-Marker.Size*2/3,yPos.Y-size.Height/2));
									break;
								case LabelPositions.Right:
									g.DrawString( textData[i], font_, Brushes.Black, new PointF(xPos.X+Marker.Size*2/3,yPos.Y-size.Height/2));
									break;
							}
						}
					}
				}
				catch
				{
					throw new NPlotException("Error in TextPlot.Draw");
				}
			}

		}


	}
}