// Copyright 2012 ESRI
// 
// All rights reserved under the copyright laws of the United States
// and applicable international laws, treaties, and conventions.
// 
// You may freely redistribute and use this sample code, with or
// without modification, provided you include the original copyright
// notice and use restrictions.
// 
// See the use restrictions.
// 

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using ESRI.ArcGIS.ADF;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Display;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.esriSystem;

namespace TriangleElement
{
  [ComVisible(true)]
  [Guid("DC8482C9-5DD6-44dc-BF3C-54B18AB813C9")]
  public interface ITriangleElement
  {
    ISimpleFillSymbol FillSymbol { get; set;}
    double Size { get; set;}
    double Angle { get; set;}
  }

  [Guid(TriangleElementClass.CLASSGUID)]
  [ClassInterface(ClassInterfaceType.None)]
  [ProgId("TriangleElement.TriangleElementClass")]
  public sealed class TriangleElementClass : ITriangleElement,
                                             IElement, 
                                             IElementProperties, 
                                             IElementProperties2, 
                                             IElementProperties3,
                                             IBoundsProperties, 
                                             ITransform2D, 
                                             IGraphicElement, 
                                             IPersistVariant,
                                             IClone,
                                             IDocumentVersionSupportGEN
  {
    #region class members

    //some win32 imports and constants
    [System.Runtime.InteropServices.DllImport("gdi32", EntryPoint = "GetDeviceCaps", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Ansi, SetLastError = true)]
    public static extern int GetDeviceCaps(int hDC, int nIndex);
    private const double          c_Cosine30          = 0.866025403784439;
    private const double          c_Deg2Rad           = (Math.PI / 180.0);
    private const double          c_Rad2Deg           = (180.0 / Math.PI);
    private const int             c_Version           = 2;
    public const string           CLASSGUID           = "cbf943e2-ce6d-49f4-a4a7-ce16f02379ad";
    public const int              LOGPIXELSX          = 88;
    public const int              LOGPIXELSY          = 90;

    private IPolygon              m_triangle          = null;
    private IPoint                m_pointGeometry     = null;
    private ISimpleFillSymbol     m_fillSymbol        = null;
    private double                m_rotation          = 0.0;
    private double                m_size              = 20.0;
    private ISelectionTracker     m_selectionTracker  = null;
    private IDisplay              m_cachedDisplay     = null;
    private ISpatialReference     m_nativeSR          = null;
    private string                m_elementName       = string.Empty;
    private string                m_elementType       = "TriangleElement";
    private object                m_customProperty    = null;
    private bool                  m_autoTrans         = true;
    private double                m_scaleRef          = 0.0;
    private esriAnchorPointEnum   m_anchorPointType   = esriAnchorPointEnum.esriCenterPoint;
    private double                m_dDeviceRatio      = 0;
    #endregion

    #region class constructor
    public TriangleElementClass()
    {
      //initialize the element's geometry
      m_triangle = new PolygonClass();
      m_triangle.SetEmpty();

      InitMembers();
    }
    #endregion

    #region ITriangleElement Members

    public ISimpleFillSymbol FillSymbol
    {
      get
      {
        return m_fillSymbol;
      }
      set
      {
        m_fillSymbol = value;
      }
    }

    public double Size
    {
      get
      {
        return m_size;
      }
      set
      {
        m_size = value;
      }
    }

    public double Angle
    {
      get
      {
        return m_rotation;
      }
      set
      {
        m_rotation = value;
      }
    }

    #endregion

    #region IElement Members

    public void Activate(IDisplay Display)
    {
      //cache the display
      m_cachedDisplay = Display;

      SetupDeviceRatio(Display.hDC, Display);

      //need to calculate the points of the triangle polygon
      if(m_triangle.IsEmpty)
        BuildTriangleGeometry(m_pointGeometry);

      //need to refresh the element's tracker
      RefreshTracker();
    }

    public void Deactivate()
    {
      m_cachedDisplay = null;
    }

    public void Draw(IDisplay Display, ITrackCancel TrackCancel)
    {      
      if (null != m_triangle && null != m_fillSymbol)
      {
        Display.SetSymbol((ISymbol)m_fillSymbol);
        Display.DrawPolygon(m_triangle);
      }
    }

    public IGeometry Geometry
    {
      get
      {
        return Clone(m_pointGeometry) as IGeometry;
      }
      set
      {
        try
        {
          m_pointGeometry = Clone(value) as IPoint;

          UpdateElementSpatialRef();
        }
        catch (Exception ex)
        {
          System.Diagnostics.Trace.WriteLine(ex.Message);
        }
      }
    }

    public bool HitTest(double x, double y, double Tolerance)
    {
      if (null == m_cachedDisplay)
        return false;

      IPoint point = new PointClass();
      point.PutCoords(x,y);

      return ((IRelationalOperator)m_triangle).Contains((IGeometry)point);
    }

    public bool Locked
    {
      get
      {
        return false;
      }
      set
      {
        
      }
    }
    
    public void QueryBounds(IDisplay Display, IEnvelope Bounds)
    {
      //return a bounding envelope
      IPolygon polygon = new PolygonClass();
      polygon.SetEmpty();

      ((ISymbol)m_fillSymbol).QueryBoundary(Display.hDC, Display.DisplayTransformation, m_triangle, polygon);

      Bounds.XMin = polygon.Envelope.XMin;
      Bounds.XMax = polygon.Envelope.XMax;
      Bounds.YMin = polygon.Envelope.YMin;
      Bounds.YMax = polygon.Envelope.YMax;
      Bounds.SpatialReference = polygon.Envelope.SpatialReference;
    }

    public void QueryOutline(IDisplay Display, IPolygon Outline)
    {
      //return a polygon which is the outline of the element
      IPolygon polygon = new PolygonClass();
      polygon.SetEmpty();
      ((ISymbol)m_fillSymbol).QueryBoundary(Display.hDC, Display.DisplayTransformation, m_triangle, polygon);
      ((IPointCollection)Outline).AddPointCollection((IPointCollection)polygon);
    }

    public ISelectionTracker SelectionTracker
    {
      get { return m_selectionTracker; }
    }

    #endregion

    #region IElementProperties Members

    /// <summary>
    /// Indicates if transform is applied to symbols and other parts of element.
    /// False = only apply transform to geometry.
    /// Update font size in ITransform2D routines
    /// </summary>
    public bool AutoTransform
    {
      get
      {
        return m_autoTrans;
      }
      set
      {
        m_autoTrans = value;
      }
    }

    public object CustomProperty
    {
      get
      {
        return m_customProperty;
      }
      set
      {
        m_customProperty = value;
      }
    }

    public string Name
    {
      get
      {
        return m_elementName;
      }
      set
      {
        m_elementName = value;
      }
    }

    public string Type
    {
      get
      {
        return m_elementType;
      }
      set
      {
        m_elementType = value;
      }
    }

    #endregion

    #region IElementProperties2 Members


    public bool CanRotate()
    {
      return true;
    }

    public double ReferenceScale
    {
      get
      {
        return m_scaleRef;
      }
      set
      {
        m_scaleRef = value;
      }
    }

    #endregion

    #region IElementProperties3 Members

    public esriAnchorPointEnum AnchorPoint
    {
      get
      {
        return m_anchorPointType;
      }
      set
      {
        m_anchorPointType = value;
      }
    }

    #endregion

    #region IBoundsProperties Members

    public bool FixedAspectRatio
    {
      get
      {
        return true;
      }
      set
      {
        throw new Exception("The method or operation is not implemented.");
      }
    }

    public bool FixedSize
    {
      get { return true; }
    }

    #endregion

    #region ITransform2D Members

    public void Move(double dx, double dy)
    {
      if (null == m_triangle)
        return;

      ((ITransform2D)m_triangle).Move(dx, dy);
      ((ITransform2D)m_pointGeometry).Move(dx, dy);
      
      RefreshTracker();
    }

    public void MoveVector(ILine v)
    {
      if (null == m_triangle)
        return;

      ((ITransform2D)m_triangle).MoveVector(v);
      ((ITransform2D)m_pointGeometry).MoveVector(v);

      RefreshTracker();
    }

    public void Rotate(IPoint Origin, double rotationAngle)
    {
      if (null == m_triangle)
        return;

      ((ITransform2D)m_triangle).Rotate(Origin, rotationAngle);
      ((ITransform2D)m_pointGeometry).Rotate(Origin, rotationAngle);

      m_rotation = rotationAngle * c_Rad2Deg;

      RefreshTracker();
    }

    public void Scale(IPoint Origin, double sx, double sy)
    {
      if (null == m_triangle)
        return;

      ((ITransform2D)m_triangle).Scale(Origin, sx, sy);
      ((ITransform2D)m_pointGeometry).Scale(Origin, sx, sy);

      if (m_autoTrans)
      {
        m_size *= Math.Max(sx, sy);
      }

      RefreshTracker();
    }

    public void Transform(esriTransformDirection direction, ITransformation transformation)
    {
      if (null == m_triangle)
        return;

      //Geometry
      ((ITransform2D)m_triangle).Transform(direction, transformation);

      IAffineTransformation2D affineTrans = (IAffineTransformation2D)transformation;
      if (affineTrans.YScale != 1.0)
        m_size *= Math.Max(affineTrans.YScale, affineTrans.XScale);

      RefreshTracker();
    }

    #endregion

    #region IGraphicElement Members

    public ISpatialReference SpatialReference
    {
      get
      {
        return m_nativeSR;
      }
      set
      {
        m_nativeSR = value;
        UpdateElementSpatialRef();
      }
    }

    #endregion

    #region IPersistVariant Members

    public UID ID
    {
      get
      {
        UID uid = new UIDClass();
        uid.Value = "{" + TriangleElementClass.CLASSGUID + "}";
        return uid;
      }
    }

    public void Load(IVariantStream Stream)
    {
      int ver = (int)Stream.Read();
      if (ver > c_Version || ver <= 0)
        throw new Exception("Wrong version!");

      InitMembers();

      m_size = (double)Stream.Read();
      m_scaleRef = (double)Stream.Read();
      m_anchorPointType = (esriAnchorPointEnum)Stream.Read();
      m_autoTrans = (bool)Stream.Read();
      m_elementType = (string)Stream.Read();
      m_elementName = (string)Stream.Read();
      m_nativeSR = Stream.Read() as ISpatialReference;
      m_fillSymbol = Stream.Read() as ISimpleFillSymbol;
      m_pointGeometry = Stream.Read() as IPoint;
      m_triangle = Stream.Read() as IPolygon;

      if (ver == 2)
      {
        m_rotation = (double)Stream.Read();
      }
    }

    public void Save(IVariantStream Stream)
    {
      Stream.Write(c_Version);

      Stream.Write(m_size);
      Stream.Write(m_scaleRef);
      Stream.Write(m_anchorPointType);
      Stream.Write(m_autoTrans);
      Stream.Write(m_elementType);
      Stream.Write(m_elementName);
      Stream.Write(m_nativeSR);
      Stream.Write(m_fillSymbol);
      Stream.Write(m_pointGeometry);
      Stream.Write(m_triangle);

      Stream.Write(m_rotation);
    }

    #endregion

    #region IClone Members

    public void Assign(IClone src)
    {

      //1. make sure that src is pointing to a valid object
      if (null == src)
      {
        throw new COMException("Invalid object.");
      }

      //2. make sure that the type of src is of type 'TriangleElementClass'
      if (!(src is TriangleElementClass))
      {
        throw new COMException("Bad object type.");
      }

      //3. assign the properties of src to the current instance
      TriangleElementClass srcTriangle = (TriangleElementClass)src;
      m_elementName = srcTriangle.Name;
      m_elementType = srcTriangle.Type;
      m_autoTrans = srcTriangle.AutoTransform;
      m_scaleRef = srcTriangle.ReferenceScale;
      m_rotation = srcTriangle.Angle;
      m_size = srcTriangle.Size;
      m_anchorPointType = srcTriangle.AnchorPoint;

      IObjectCopy objCopy = new ObjectCopyClass();

      //take care of the custom property
      if (null != srcTriangle.CustomProperty)
      {
        if (srcTriangle.CustomProperty is IClone)
          m_customProperty = (object)((IClone)srcTriangle.CustomProperty).Clone();
        else if (srcTriangle.CustomProperty is IPersistStream)
        {
          m_customProperty = objCopy.Copy((object)srcTriangle.CustomProperty);
        }
        else if (srcTriangle.CustomProperty.GetType().IsSerializable)
        {
          //serialize to a memory stream
          MemoryStream memoryStream = new MemoryStream();
          BinaryFormatter binaryFormatter = new BinaryFormatter();
          binaryFormatter.Serialize(memoryStream, srcTriangle.CustomProperty);
          byte[] bytes = memoryStream.ToArray();

          memoryStream = new MemoryStream(bytes);
          m_customProperty = binaryFormatter.Deserialize(memoryStream);
        }
      }

      if (null != srcTriangle.SpatialReference)
        m_nativeSR = objCopy.Copy(srcTriangle.SpatialReference) as ISpatialReference;
      else
        m_nativeSR = null;

      if (null != srcTriangle.FillSymbol)
      {
        m_fillSymbol = objCopy.Copy(srcTriangle.FillSymbol) as ISimpleFillSymbol;
      }
      else
        m_fillSymbol = null;

      if (null != srcTriangle.Geometry)
      {
        m_triangle = objCopy.Copy(srcTriangle.Geometry) as IPolygon;
        m_pointGeometry = objCopy.Copy(((IArea)m_triangle).Centroid) as IPoint;
      }
      else
      {
        m_triangle = null;
        m_pointGeometry = null;
      }
    }

    public IClone Clone()
    {
      TriangleElementClass triangle = new TriangleElementClass();
      triangle.Assign((IClone)this);

      return (IClone)triangle;
    }

    public bool IsEqual(IClone other)
    {
      //1. make sure that the 'other' object is pointing to a valid object
      if (null == other)
        throw new COMException("Invalid object.");

      //2. verify the type of 'other'
      if (!(other is TriangleElementClass))
        throw new COMException("Bad object type.");

      TriangleElementClass otherTriangle = (TriangleElementClass)other;
      //test that all of the object's properties are the same.
      //please note the usage of IsEqual when using ArcObjects components that
      //supports cloning
      if (otherTriangle.Name == m_elementName &&
          otherTriangle.Type == m_elementType &&
          otherTriangle.AutoTransform == m_autoTrans &&
          otherTriangle.ReferenceScale == m_scaleRef &&
          otherTriangle.Angle == m_rotation &&
          otherTriangle.Size == m_size &&
          otherTriangle.AnchorPoint == m_anchorPointType &&
          ((IClone)otherTriangle.Geometry).IsEqual((IClone)m_triangle) &&
          ((IClone)otherTriangle.FillSymbol).IsEqual((IClone)m_fillSymbol) &&
          ((IClone)otherTriangle.SpatialReference).IsEqual((IClone)m_nativeSR))
        return true;

      return false;
    }

    public bool IsIdentical(IClone other)
    {
      //1. make sure that the 'other' object is pointing to a valid object
      if (null == other)
        throw new COMException("Invalid object.");

      //2. verify the type of 'other'
      if (!(other is TriangleElementClass))
        throw new COMException("Bad object type.");

      //3. test if the other is the 'this'
      if ((TriangleElementClass)other == this)
        return true;

      return false;
    }

    #endregion

    #region IDocumentVersionSupportGEN Members

    public object ConvertToSupportedObject(esriArcGISVersion docVersion)
    {
      //in case of 8.3, create a character marker element and use a triangle marker...
      ICharacterMarkerSymbol charMarkerSymbol = new CharacterMarkerSymbolClass();
      charMarkerSymbol.Color = m_fillSymbol.Color;
      charMarkerSymbol.Angle = m_rotation;
      charMarkerSymbol.Size = m_size;
      charMarkerSymbol.Font = ESRI.ArcGIS.ADF.Connection.Local.Converter.ToStdFont(new Font("ESRI Default Marker", (float)m_size, FontStyle.Regular));
      charMarkerSymbol.CharacterIndex = 184;

      IMarkerElement markerElement = new MarkerElementClass();
      markerElement.Symbol = (IMarkerSymbol)charMarkerSymbol;

      IPoint point = ((IClone)m_pointGeometry).Clone() as IPoint;
      IElement element = (IElement)markerElement;
      element.Geometry = (IGeometry)point;

      return element;
    }

    public bool IsSupportedAtVersion(esriArcGISVersion docVersion)
    {
      //support all versions except 8.3
      if (esriArcGISVersion.esriArcGISVersion83 == docVersion)
        return false;
      else
        return true;
    }

    #endregion

    #region private methods
    private IClone Clone(object obj)
    {
      if (null == obj || !(obj is IClone))
        return null;

      return ((IClone)obj).Clone();
    }

    private int TwipsPerPixelX()
    {
      return 16;
    }

    private int TwipsPerPixelY()
    {
      return 16;
    }

    private void SetupDeviceRatio(int hDC, ESRI.ArcGIS.Display.IDisplay display)
    {
      if (display.DisplayTransformation != null)
      {
        if (display.DisplayTransformation.Resolution != 0)
        {
          m_dDeviceRatio = display.DisplayTransformation.Resolution / 72;
          //  Check the ReferenceScale of the display transformation. If not zero, we need to
          //  adjust the Size, XOffset and YOffset of the Symbol we hold internally before drawing.
          if (display.DisplayTransformation.ReferenceScale != 0)
            m_dDeviceRatio = m_dDeviceRatio * display.DisplayTransformation.ReferenceScale / display.DisplayTransformation.ScaleRatio;
        }
      }
      else
      {
        // If we don't have a display transformation, calculate the resolution
        // from the actual device.
        if (display.hDC != 0)
        {
          // Get the resolution from the device context hDC.
          m_dDeviceRatio = System.Convert.ToDouble(GetDeviceCaps(hDC, LOGPIXELSX)) / 72;
        }
        else
        {
          // If invalid hDC assume we're drawing to the screen.
          m_dDeviceRatio = 1 / (TwipsPerPixelX() / 20); // 1 Point = 20 Twips.
        }
      }
    }

    private double PointsToMap(IDisplayTransformation displayTransform, double dPointSize)
    {
      double tempPointsToMap = 0;
      if (displayTransform == null)
        tempPointsToMap = dPointSize * m_dDeviceRatio;
      else
      {
        tempPointsToMap = displayTransform.FromPoints(dPointSize);
      }
      return tempPointsToMap;
    }

    private void BuildTriangleGeometry(IPoint pointGeometry)
    {
      try
      {
        if (null == m_triangle || null == pointGeometry || null == m_cachedDisplay)
          return;

        m_triangle.SpatialReference = pointGeometry.SpatialReference;
        m_triangle.SetEmpty();

        object missing = System.Reflection.Missing.Value;
        IPointCollection pointCollection = (IPointCollection)m_triangle;

        double radius = PointsToMap(m_cachedDisplay.DisplayTransformation, m_size);

        double X = pointGeometry.X;
        double Y = pointGeometry.Y;

        IPoint point = new PointClass();
        point.X = X + radius * c_Cosine30;
        point.Y = Y - 0.5 * radius;
        pointCollection.AddPoint(point, ref missing, ref missing);

        point = new PointClass();
        point.X = X;
        point.Y = Y + radius;
        pointCollection.AddPoint(point, ref missing, ref missing);

        point = new PointClass();
        point.X = X - radius * c_Cosine30;
        point.Y = Y - 0.5 * radius;
        pointCollection.AddPoint(point, ref missing, ref missing);

        m_triangle.Close();

        if (m_rotation != 0.0)
        {
          ((ITransform2D)pointCollection).Rotate(pointGeometry, m_rotation * c_Deg2Rad);
        }

        return;
      }
      catch (Exception ex)
      {
        System.Diagnostics.Trace.WriteLine(ex.Message);
      }
    }

    private void SetDefaultDymbol()
    {
      IColor color = (IColor)ESRI.ArcGIS.ADF.Connection.Local.Converter.ToRGBColor(Color.Black);
      ISimpleLineSymbol lineSymbol = new SimpleLineSymbolClass();
      lineSymbol.Style = esriSimpleLineStyle.esriSLSSolid;
      lineSymbol.Width = 1.0;
      lineSymbol.Color = color;

      color = (IColor)ESRI.ArcGIS.ADF.Connection.Local.Converter.ToRGBColor(Color.Navy);
      if (null == m_fillSymbol)
        m_fillSymbol = new SimpleFillSymbolClass();
      m_fillSymbol.Color = color;
      m_fillSymbol.Style = esriSimpleFillStyle.esriSFSSolid;
      m_fillSymbol.Outline = (ILineSymbol)lineSymbol;
    }


    /// <summary>
    /// assign the triangle's geometry to the selection tracker
    /// </summary>
    private void RefreshTracker()
    {
      if (null == m_cachedDisplay)
        return;

      m_selectionTracker.Display = (IScreenDisplay)m_cachedDisplay;

      
      IPolygon outline = new PolygonClass(); 
      this.QueryOutline(m_cachedDisplay, outline);

      m_selectionTracker.Geometry = (IGeometry)outline;
    }

    private void UpdateElementSpatialRef()
    {
      if (null == m_cachedDisplay ||
          null == m_nativeSR ||
          null == m_triangle ||
          null == m_cachedDisplay.DisplayTransformation.SpatialReference)
        return;

      if (null == m_triangle.SpatialReference)
        m_triangle.SpatialReference = m_cachedDisplay.DisplayTransformation.SpatialReference;

      m_triangle.Project(m_nativeSR);

      RefreshTracker();
    }

    private void InitMembers()
    {
      //initialize the selection tracker
      m_selectionTracker = new PolygonTrackerClass();
      m_selectionTracker.Locked = false;
      m_selectionTracker.ShowHandles = true;

      //set a default symbol
      SetDefaultDymbol();
    }
    #endregion

  }
}