mcs/class/System.Web/System.Web.UI.WebControls/DataGridColumnCollection.cs

   1 /**\r
   2  * Namespace: System.Web.UI.WebControls\r
   3  * Class:     DataGridColumnCollection\r
   4  *\r
   5  * Author:  Gaurav Vaish\r
   6  * Maintainer: gvaish@iitk.ac.in\r
   7  * Contact: <my_scripts2001@yahoo.com>, <gvaish@iitk.ac.in>\r
   8  * Implementation: yes\r
   9  * Status:  ??%\r
  10  *\r
  11  * (C) Gaurav Vaish (2002)\r
  12  */\r
  13 \r
  14 using System;
  15 using System.ComponentModel;\r
  16 using System.Collections;\r
  17 using System.Web;\r
  18 using System.Web.UI;\r
  19 \r
  20 namespace System.Web.UI.WebControls\r
  21 {\r
  22         public sealed class DataGridColumnCollection : ICollection, IEnumerable, IStateManager\r
  23         {\r
  24                 private DataGrid  owner;\r
  25                 private ArrayList columns;\r
  26                 private bool      trackViewState;\r
  27 \r
  28                 public DataGridColumnCollection(DataGrid owner, ArrayList columns)\r
  29                 {\r
  30                         this.owner   = owner;\r
  31                         this.columns = columns;\r
  32                 }\r
  33
  34                 [Browsable (false)]\r
  35                 public int Count\r
  36                 {\r
  37                         get\r
  38                         {\r
  39                                 return columns.Count;\r
  40                         }\r
  41                 }\r
  42
  43                 [Browsable (false)]\r
  44                 public bool IsReadOnly\r
  45                 {\r
  46                         get\r
  47                         {\r
  48                                 return false;\r
  49                         }\r
  50                 }\r
  51
  52                 [Browsable (false)]\r
  53                 public bool IsSynchronized\r
  54                 {\r
  55                         get\r
  56                         {\r
  57                                 return false;\r
  58                         }\r
  59                 }\r
  60
  61                 [Browsable (false)]\r
  62                 public DataGridColumn this[int index]\r
  63                 {\r
  64                         get\r
  65                         {\r
  66                                 return (DataGridColumn)(columns[index]);\r
  67                         }\r
  68                 }\r
  69
  70                 [Browsable (false)]\r
  71                 public object SyncRoot\r
  72                 {\r
  73                         get\r
  74                         {\r
  75                                 return this;\r
  76                         }\r
  77                 }\r
  78 \r
  79                 public void Add(DataGridColumn column)\r
  80                 {\r
  81                         AddAt(-1, column);\r
  82                 }\r
  83 \r
  84                 public void AddAt(int index, DataGridColumn column)\r
  85                 {\r
  86                         if(index == -1)\r
  87                         {\r
  88                                 columns.Add(column);\r
  89                         } else\r
  90                         {\r
  91                                 columns.Insert(index, column);\r
  92                         }\r
  93 \r
  94                         column.SetOwner (owner);\r
  95                         if(trackViewState)\r
  96                         {\r
  97                                 ((IStateManager)column).TrackViewState();\r
  98                         }\r
  99                         OnColumnsChanged();\r
 100                 }\r
 101 \r
 102                 internal void OnColumnsChanged()\r
 103                 {\r
 104                         if(owner != null)\r
 105                         {\r
 106                                 owner.OnColumnsChanged();\r
 107                         }\r
 108                 }\r
 109 \r
 110                 public void Clear()\r
 111                 {\r
 112                         columns.Clear();\r
 113                         OnColumnsChanged();\r
 114                 }\r
 115 \r
 116                 public void CopyTo(Array array, int index)\r
 117                 {\r
 118                         foreach(DataGridColumn current in this)\r
 119                         {\r
 120                                 array.SetValue(current, index++);\r
 121                         }\r
 122                 }\r
 123 \r
 124                 public IEnumerator GetEnumerator()\r
 125                 {\r
 126                         return columns.GetEnumerator();\r
 127                 }\r
 128 \r
 129                 public int IndexOf(DataGridColumn column)\r
 130                 {\r
 131                         if(column != null)\r
 132                         {\r
 133                                 return columns.IndexOf(column);\r
 134                         }\r
 135                         return -1;\r
 136                 }\r
 137 \r
 138                 public void Remove(DataGridColumn column)\r
 139                 {\r
 140                         if(column != null)\r
 141                         {\r
 142                                 RemoveAt(IndexOf(column));\r
 143                         }\r
 144                 }\r
 145 \r
 146                 public void RemoveAt(int index)\r
 147                 {\r
 148                         if(index >= 0 && index < columns.Count)\r
 149                         {\r
 150                                 columns.RemoveAt(index);\r
 151                                 OnColumnsChanged();\r
 152                                 return;\r
 153                         }\r
 154                         //This exception is not documented, but thrown\r
 155                         throw new ArgumentOutOfRangeException("string");\r
 156                 }\r
 157 \r
 158                 object IStateManager.SaveViewState()\r
 159                 {\r
 160                         if (columns.Count == 0)\r
 161                                 return null;\r
 162 \r
 163                         ArrayList retVal = new ArrayList (columns.Count);
 164                         bool found = false;\r
 165                         foreach (IStateManager current in columns) {
 166                                 object o = current.SaveViewState ();\r
 167                                 retVal.Add (o);
 168                                 if (o != null)
 169                                         found = true;
 170                         }\r
 171 \r
 172                         if (!found)
 173                                 return null;
 174
 175                         return retVal;\r
 176                 }\r
 177 \r
 178                 void IStateManager.LoadViewState(object savedState)\r
 179                 {\r
 180                         if (savedState == null || !(savedState is ArrayList))\r
 181                                 return;\r
 182 \r
 183                         ArrayList list = (ArrayList) savedState;\r
 184                         int end = list.Count;\r
 185                         if (end != columns.Count)\r
 186                                 return;\r
 187 \r
 188                         for (int i = 0; i < end; i++) {\r
 189                                 IStateManager col = (IStateManager) columns [i];\r
 190                                 col.LoadViewState (list [i]);\r
 191                         }\r
 192                 }\r
 193
 194                 void IStateManager.TrackViewState()
 195                 {
 196                         trackViewState = true;
 197                         foreach (IStateManager col in columns)
 198                                 col.TrackViewState ();
 199                 }
 200
 201                 bool IStateManager.IsTrackingViewState\r
 202                 {\r
 203                         get\r
 204                         {\r
 205                                 return trackViewState;\r
 206                         }\r
 207                 }\r
 208         }\r
 209 }\r