nplot/src/LabelPointPlot.cs

/*
 * NPlot - A charting library for .NET
 * 
 * LabelPointPlot.cs
 * Copyright (C) 2003-2006 Matt Howlett and others.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.Collections;
using System.Data;
using System.Drawing;

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

        private Font font_ = new Font("Arial", 8.0f);
        private LabelPositions labelTextPosition_ = LabelPositions.Above;

        /// <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; }
        }

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

        /// <summary>
        /// The Font used to write text.
        /// </summary>
        public Font Font
        {
            get { return font_; }
            set { font_ = value; }
        }

        /// <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(DataSource, DataMember, OrdinateData, AbscissaData);

            TextDataAdapter textData =
                new TextDataAdapter(DataSource, DataMember, 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], 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");
                }
            }
        }

        /// <summary>
        /// This class us used in conjunction with SequenceAdapter to interpret data
        /// specified to the TextPlot class.
        /// </summary>
        private class TextDataAdapter
        {
            private readonly string dataMember_;
            private readonly object dataSource_;
            private readonly object data_;

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

                        DataRowCollection rows;

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

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

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

                        return (string) ((rows[i]))[(string) data_];
                    }

                    if (data_ is ArrayList)
                    {
                        object dataPoint = ((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 ArrayList)
                    {
                        return ((ArrayList) data_).Count;
                    }
                    throw new NPlotException("Text data not in correct format");
                }
            }
        }
    }
}