mcs/class/System.Data/System.Data/RelatedDataView.cs

   1 //\r
   2 // System.Data.RelatedDataView\r
   3 //\r
   4 // Author:\r
   5 //   Konstantin Triger (kostat@mainsoft.com)\r
   6 //\r
   7 \r
   8 using System;\r
   9 using System.Collections;\r
  10 using Mono.Data.SqlExpressions;\r
  11 using System.Data.Common;\r
  12 \r
  13 namespace System.Data\r
  14 {\r
  15         /// <summary>\r
  16         /// Summary description for RelatedDataView.\r
  17         /// </summary>\r
  18         internal class RelatedDataView : DataView, IExpression\r
  19         {\r
  20                 #region Fields\r
  21                 \r
  22                 object[] _keyValues;\r
  23                 DataColumn[] _columns;\r
  24 \r
  25                 #endregion // Fields\r
  26 \r
  27                 #region Constructors\r
  28                 internal RelatedDataView(DataColumn[] relatedColumns,object[] keyValues)\r
  29                 {\r
  30                         dataTable = relatedColumns[0].Table;\r
  31                         rowState = DataViewRowState.CurrentRows;\r
  32                         _columns = relatedColumns;\r
  33                         _keyValues = keyValues;\r
  34 \r
  35                         Open();\r
  36                 }\r
  37 \r
  38                 #endregion // Constructors\r
  39 \r
  40                 #region Methods\r
  41 \r
  42                 internal override IExpression FilterExpression {\r
  43                         get {\r
  44                                 return this;\r
  45                         }\r
  46                 }\r
  47 \r
  48 \r
  49                 #endregion // Methods\r
  50 \r
  51                 public override bool Equals(object obj)\r
  52                 {\r
  53                         if (!(obj is RelatedDataView)) {\r
  54                                 if (base.FilterExpression == null)\r
  55                                         return false;\r
  56                                 return base.FilterExpression.Equals (obj);\r
  57                         }\r
  58 \r
  59                         RelatedDataView other = (RelatedDataView) obj;\r
  60                         if (_columns.Length != other._columns.Length)\r
  61                                 return false;\r
  62             \r
  63                         for (int i = 0; i < _columns.Length; i++)\r
  64                                 if (!_columns[i].Equals(other._columns [i]) ||\r
  65                     !_keyValues[i].Equals(other._keyValues [i]))\r
  66                                         return false;\r
  67                         \r
  68                         if (!other.FilterExpression.Equals (base.FilterExpression))\r
  69                                 return false;\r
  70 \r
  71                         return true;\r
  72                 }\r
  73 \r
  74                 public override int GetHashCode()\r
  75                 {\r
  76                         int hashCode = 0;\r
  77                         for (int i = 0; i < _columns.Length; i++) {\r
  78                                 hashCode ^= _columns [i].GetHashCode ();\r
  79                                 hashCode ^= _keyValues [i].GetHashCode ();\r
  80                         }\r
  81 \r
  82                         if (base.FilterExpression != null)\r
  83                                 hashCode ^= base.FilterExpression.GetHashCode ();\r
  84 \r
  85                         return hashCode;\r
  86                 }\r
  87 \r
  88                 #region IExpression Members\r
  89 \r
  90                 public object Eval(DataRow row) {\r
  91                         return EvalBoolean(row);\r
  92                 }\r
  93 \r
  94                 public bool EvalBoolean(DataRow row) {\r
  95                         for (int i = 0; i < _columns.Length; i++)\r
  96                                 if (!row[_columns[i]].Equals(_keyValues[i]))\r
  97                                         return false;\r
  98 \r
  99                         IExpression filter = base.FilterExpression;\r
 100                         return filter != null ? filter.EvalBoolean(row) : true;\r
 101                 }\r
 102 \r
 103                 public bool DependsOn(DataColumn other) {\r
 104                         for (int i = 0; i < _columns.Length; i++)\r
 105                                 if (_columns[i] == other)\r
 106                                         return true;\r
 107 \r
 108                         IExpression filter = base.FilterExpression;\r
 109                         return filter != null ? filter.DependsOn(other) : false;\r
 110                 }\r
 111                 \r
 112                 void IExpression.ResetExpression()
 113                 {
 114                 }\r
 115 \r
 116                 #endregion\r
 117         }\r
 118 }\r