RelatedDataView.cs :  » 2.6.4-mono-.net-core » System.Data » System » Data » C# / CSharp Open Source

//
// System.Data.RelatedDataView
//
// Author:
//   Konstantin Triger (kostat@mainsoft.com)
//

using System;
using System.Collections;
using Mono.Data.SqlExpressions;
using System.Data.Common;

namespace System.Data{
  /// <summary>
  /// Summary description for RelatedDataView.
  /// </summary>
  internal class RelatedDataView : DataView, IExpression
  {
    #region Fields
    
    object[] _keyValues;
    DataColumn[] _columns;

    #endregion // Fields

    #region Constructors
    internal RelatedDataView(DataColumn[] relatedColumns,object[] keyValues)
    {
      dataTable = relatedColumns[0].Table;
      rowState = DataViewRowState.CurrentRows;
      _columns = relatedColumns;
      _keyValues = keyValues;

      Open();
    }

    #endregion // Constructors

    #region Methods

    internal override IExpression FilterExpression {
      get {
        return this;
      }
    }


    #endregion // Methods

    public override bool Equals(object obj)
    {
      if (!(obj is RelatedDataView)) {
        if (base.FilterExpression == null)
          return false;
        return base.FilterExpression.Equals (obj);
      }

      RelatedDataView other = (RelatedDataView) obj;
      if (_columns.Length != other._columns.Length)
        return false;
            
      for (int i = 0; i < _columns.Length; i++)
        if (!_columns[i].Equals(other._columns [i]) ||
                    !_keyValues[i].Equals(other._keyValues [i]))
          return false;
      
      if (!other.FilterExpression.Equals (base.FilterExpression))
        return false;

      return true;
    }

    public override int GetHashCode()
    {
      int hashCode = 0;
      for (int i = 0; i < _columns.Length; i++) {
        hashCode ^= _columns [i].GetHashCode ();
        hashCode ^= _keyValues [i].GetHashCode ();
      }

      if (base.FilterExpression != null)
        hashCode ^= base.FilterExpression.GetHashCode ();

      return hashCode;
    }

    #region IExpression Members

    public object Eval(DataRow row) {
      return EvalBoolean(row);
    }

    public bool EvalBoolean(DataRow row) {
      for (int i = 0; i < _columns.Length; i++)
        if (!row[_columns[i]].Equals(_keyValues[i]))
          return false;

      IExpression filter = base.FilterExpression;
      return filter != null ? filter.EvalBoolean(row) : true;
    }

    public bool DependsOn(DataColumn other) {
      for (int i = 0; i < _columns.Length; i++)
        if (_columns[i] == other)
          return true;

      IExpression filter = base.FilterExpression;
      return filter != null ? filter.DependsOn(other) : false;
    }
    
    void IExpression.ResetExpression()
    {
    }

    #endregion
  }
}