mcs/class/System.Web/System.Web.UI/DataSourceSelectArguments.cs

   1 //
   2 // System.Web.UI.DataSourceSelectArguments.cs
   3 //
   4 // Author:
   5 //   Sanjay Gupta <gsanjay@novell.com>
   6 //
   7 // (C) 2004 Novell, Inc (http://www.novell.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 #if NET_2_0
  32 using System;
  33
  34 namespace System.Web.UI
  35 {
  36         public sealed class DataSourceSelectArguments
  37         {
  38                 string sortExpression;
  39                 int startingRowIndex;
  40                 int maxRows;
  41                 bool getTotalRowCount;
  42                 int totalRowCount = -1;
  43                 DataSourceCapabilities dsc = DataSourceCapabilities.None;
  44
  45                 // MSDN: Gets a DataSourceSelectArguments object with the sort expression set to Empty.
  46                 public static DataSourceSelectArguments Empty {
  47                         get {
  48                                 return new DataSourceSelectArguments ();
  49                         }
  50                 }
  51
  52                 public DataSourceSelectArguments ()
  53                 {
  54                 }
  55
  56                 public DataSourceSelectArguments (string sortExpression)
  57                 {
  58                         this.sortExpression = sortExpression;
  59                 }
  60
  61                 public DataSourceSelectArguments (int startingRowIndex, int maxRows)
  62                 {
  63                         this.startingRowIndex = startingRowIndex;
  64                         this.maxRows = maxRows;
  65                 }
  66
  67                 public DataSourceSelectArguments (string sortExpression, int startingRowIndex, int maxRows)
  68                 {
  69                         this.sortExpression = sortExpression;
  70                         this.startingRowIndex = startingRowIndex;
  71                         this.maxRows = maxRows;
  72                 }
  73
  74                 public void AddSupportedCapabilities (DataSourceCapabilities srcCapabilities)
  75                 {
  76                         this.dsc = this.dsc | srcCapabilities;
  77                 }
  78
  79                 // MSDN: The DataSourceSelectArguments class overrides the Object.Equals method to test
  80                 // equality using the various properties of the objects. If the MaximumRows,
  81                 // RetrieveTotalRowCount, SortExpression, StartRowIndex, and TotalRowCount properties
  82                 // are all equal in value, the Equals(Object) method returns true.
  83                 public override bool Equals (object obj)
  84                 {
  85                         DataSourceSelectArguments args = obj as DataSourceSelectArguments;
  86                         if (args == null)
  87                                 return false;
  88
  89                         return (this.SortExpression == args.SortExpression &&
  90                                 this.StartRowIndex == args.StartRowIndex &&
  91                                 this.MaximumRows == args.MaximumRows &&
  92                                 this.RetrieveTotalRowCount == args.RetrieveTotalRowCount &&
  93                                 this.TotalRowCount == args.TotalRowCount);
  94                 }
  95
  96                 public override int GetHashCode ()
  97                 {
  98                         int hash = SortExpression != null ? SortExpression.GetHashCode() : 0;
  99                         return hash ^ StartRowIndex ^ MaximumRows ^ RetrieveTotalRowCount.GetHashCode() ^ TotalRowCount;
 100                 }
 101
 102                 // The RaiseUnsupportedCapabilitiesError method is used by data-bound controls
 103                 // to compare additional requested capabilities represented by the properties
 104                 // of the DataSourceSelectArguments class, such as the ability to sort or page
 105                 // through a result set, with the capabilities supported by the data source view.
 106                 // The view calls its own RaiseUnsupportedCapabilityError method for each possible
 107                 // capability defined in the DataSourceCapabilities enumeration.
 108                 public void RaiseUnsupportedCapabilitiesError (DataSourceView view)
 109                 {
 110                         DataSourceCapabilities requestedCaps = RequestedCapabilities;
 111                         DataSourceCapabilities notSupportedCaps = (requestedCaps ^ dsc) & requestedCaps;
 112                         if (notSupportedCaps == DataSourceCapabilities.None)
 113                                 return;
 114
 115                         if ((notSupportedCaps & DataSourceCapabilities.RetrieveTotalRowCount) > 0)
 116                                 notSupportedCaps = DataSourceCapabilities.RetrieveTotalRowCount;
 117                         else if ((notSupportedCaps & DataSourceCapabilities.Page) > 0)
 118                                 notSupportedCaps = DataSourceCapabilities.Page;
 119
 120                         view.RaiseUnsupportedCapabilityError (notSupportedCaps);
 121                 }
 122
 123                 DataSourceCapabilities RequestedCapabilities {
 124                         get {
 125                                 DataSourceCapabilities caps = DataSourceCapabilities.None;
 126                                 if (!String.IsNullOrEmpty (SortExpression))
 127                                         caps |= DataSourceCapabilities.Sort;
 128                                 if (RetrieveTotalRowCount)
 129                                         caps |= DataSourceCapabilities.RetrieveTotalRowCount;
 130                                 if (StartRowIndex > 0 || MaximumRows > 0)
 131                                         caps |= DataSourceCapabilities.Page;
 132                                 return caps;
 133                         }
 134                 }
 135
 136                 public int MaximumRows {
 137                         get { return this.maxRows; }
 138                         set { this.maxRows = value; }
 139                 }
 140
 141                 public bool RetrieveTotalRowCount  {
 142                         get { return this.getTotalRowCount; }
 143                         set { this.getTotalRowCount = value; }
 144                 }
 145
 146                 public string SortExpression {
 147                         get {
 148                                 if (sortExpression == null)
 149                                         return String.Empty;
 150                                 return this.sortExpression;
 151                         }
 152                         set { this.sortExpression = value; }
 153                 }
 154
 155                 public int StartRowIndex {
 156                         get { return this.startingRowIndex; }
 157                         set { this.startingRowIndex = value; }
 158                 }
 159
 160                 public int TotalRowCount {
 161                         get { return this.totalRowCount; }
 162                         set { this.totalRowCount = value; }
 163                 }
 164         }
 165 }
 166 #endif