mcs/class/System.Web.Extensions/System.Web.UI.WebControls/DataPagerField.cs

   1 //
   2 // System.Web.UI.WebControls.DataPagerField
   3 //
   4 // Authors:
   5 //   Marek Habersack (mhabersack@novell.com)
   6 //
   7 // (C) 2007-2008 Novell, Inc
   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 using System;
  31 using System.Collections.Specialized;
  32 using System.ComponentModel;
  33 using System.Globalization;
  34 using System.Security.Permissions;
  35 using System.Text;
  36 using System.Web;
  37 using System.Web.UI;
  38
  39 namespace System.Web.UI.WebControls
  40 {
  41         [AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  42         [AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
  43         public abstract class DataPagerField : IStateManager
  44         {
  45                 static readonly object FieldChangedEvent = new object ();
  46
  47                 EventHandlerList events;
  48                 StateBag _state = new StateBag ();
  49                 DataPager _dataPager;
  50
  51                 bool _queryStringHandled;
  52                 bool _isTrackingViewState;
  53                 string _queryStringNavigateUrl;
  54
  55                 internal event EventHandler FieldChanged {
  56                         add { AddEventHandler (FieldChangedEvent, value); }
  57                         remove { RemoveEventHandler (FieldChangedEvent, value); }
  58                 }
  59
  60                 protected DataPagerField ()
  61                 {
  62                 }
  63
  64                 protected internal DataPagerField CloneField ()
  65                 {
  66                         DataPagerField ret = CreateField ();
  67                         CopyProperties (ret);
  68
  69                         return ret;
  70                 }
  71
  72                 protected virtual void CopyProperties (DataPagerField newField)
  73                 {
  74                         // assuming we should copy only the public properties
  75                         newField.Visible = Visible;
  76                 }
  77
  78                 public abstract void CreateDataPagers (DataPagerFieldItem container, int startRowIndex, int maximumRows,
  79                                                        int totalRowCount, int fieldIndex);
  80
  81                 protected abstract DataPagerField CreateField ();
  82
  83                 protected string GetQueryStringNavigateUrl (int pageNumber)
  84                 {
  85                         if (_queryStringNavigateUrl == null && _dataPager != null) {
  86                                 HttpContext ctx = HttpContext.Current;
  87                                 HttpRequest req = ctx != null ? ctx.Request : null;
  88                                 string queryFieldName = _dataPager.QueryStringField;
  89
  90                                 if (req != null) {
  91                                         StringBuilder sb = new StringBuilder (req.Path + "?");
  92                                         NameValueCollection coll = req.QueryString;
  93
  94                                         foreach (string k in coll.AllKeys) {
  95                                                 if (String.Compare (k, queryFieldName, StringComparison.OrdinalIgnoreCase) == 0)
  96                                                         continue;
  97                                                 sb.Append (HttpUtility.UrlEncode (k) + "=" + HttpUtility.UrlEncode (coll [k]) + "&");
  98                                         }
  99
 100                                         sb.Append (queryFieldName + "=");
 101                                         _queryStringNavigateUrl = sb.ToString ();
 102                                 } else
 103                                         _queryStringNavigateUrl = String.Empty;
 104                         }
 105
 106                         return _queryStringNavigateUrl + pageNumber.ToString (CultureInfo.InvariantCulture);
 107                 }
 108
 109                 public abstract void HandleEvent (CommandEventArgs e);
 110
 111                 protected virtual void LoadViewState (Object savedState)
 112                 {
 113                         if (savedState == null)
 114                                 return;
 115
 116                         ((IStateManager) ViewState).LoadViewState (savedState);
 117                 }
 118
 119                 protected virtual void OnFieldChanged ()
 120                 {
 121                         InvokeEvent (FieldChangedEvent, EventArgs.Empty);
 122                 }
 123
 124                 protected virtual object SaveViewState ()
 125                 {
 126                         return ((IStateManager) ViewState).SaveViewState ();
 127                 }
 128
 129                 protected virtual void TrackViewState ()
 130                 {
 131                         _isTrackingViewState = true;
 132                         ((IStateManager)ViewState).TrackViewState ();
 133                 }
 134
 135                 protected DataPager DataPager {
 136                         get { return _dataPager; }
 137                 }
 138
 139                 protected bool QueryStringHandled {
 140                         get { return _queryStringHandled; }
 141                         set { _queryStringHandled = value; }
 142                 }
 143
 144                 protected string QueryStringValue {
 145                         get {
 146                                 if (_dataPager == null)
 147                                         return String.Empty;
 148
 149                                 HttpContext ctx = HttpContext.Current;
 150                                 HttpRequest req = ctx != null ? ctx.Request : null;
 151
 152                                 if (req == null)
 153                                         return String.Empty;
 154
 155                                 return req.QueryString [_dataPager.QueryStringField];
 156                         }
 157                 }
 158
 159                 protected StateBag ViewState {
 160                         get { return _state; }
 161                 }
 162
 163                 public bool Visible {
 164                         get {
 165                                 object o = ViewState ["Visible"];
 166                                 if (o == null)
 167                                         return true;
 168
 169                                 return (bool) o;
 170                         }
 171
 172                         set {
 173                                 if (value != Visible) {
 174                                         ViewState ["Visible"] = value;
 175                                         OnFieldChanged ();
 176                                 }
 177                         }
 178                 }
 179
 180                 protected bool IsTrackingViewState {
 181                         get { return _isTrackingViewState; }
 182                 }
 183
 184                 void IStateManager.TrackViewState ()
 185                 {
 186                         TrackViewState ();
 187                 }
 188
 189                 bool IStateManager.IsTrackingViewState {
 190                         get { return IsTrackingViewState; }
 191                 }
 192
 193                 object IStateManager.SaveViewState ()
 194                 {
 195                         return SaveViewState ();
 196                 }
 197
 198                 void IStateManager.LoadViewState (object state)
 199                 {
 200                         LoadViewState (state);
 201                 }
 202
 203                 internal void SetDataPager (DataPager pager)
 204                 {
 205                         _dataPager = pager;
 206                 }
 207
 208                 internal bool GetQueryModeStartRowIndex (int totalRowCount, int maximumRows, ref int startRowIndex, ref bool setPagePropertiesNeeded)
 209                 {
 210                         bool queryMode = !String.IsNullOrEmpty (DataPager.QueryStringField);
 211                         if (!queryMode || QueryStringHandled)
 212                                 return queryMode;
 213
 214                         QueryStringHandled = true;
 215
 216                         // We need to calculate the new start index since it is probably out
 217                         // of date because the GET parameter with the page number hasn't
 218                         // been processed yet
 219                         int pageNumber;
 220                         try {
 221                                 pageNumber = Int32.Parse (QueryStringValue);
 222                         } catch {
 223                                 // ignore
 224                                 pageNumber = -1;
 225                         }
 226
 227                         if (pageNumber >= 0) {
 228                                 pageNumber--; // we're zero-based since we're calculating
 229                                 // the offset/index
 230                                 if (pageNumber >= 0) {
 231                                         // zero-based calculation again
 232                                         int pageCount = (totalRowCount - 1) / maximumRows;
 233                                         if (pageNumber <= pageCount) {
 234                                                 startRowIndex = pageNumber * maximumRows;
 235                                                 setPagePropertiesNeeded = true;
 236                                         }
 237                                 }
 238                         }
 239
 240                         return true;
 241                 }
 242
 243                 void AddEventHandler (object key, EventHandler handler)
 244                 {
 245                         if (events == null)
 246                                 events = new EventHandlerList ();
 247                         events.AddHandler (key, handler);
 248                 }
 249
 250                 void RemoveEventHandler (object key, EventHandler handler)
 251                 {
 252                         if (events == null)
 253                                 return;
 254                         events.RemoveHandler (key, handler);
 255                 }
 256
 257                 void InvokeEvent (object key, EventArgs args)
 258                 {
 259                         if (events == null)
 260                                 return;
 261
 262                         EventHandler eh = events [key] as EventHandler;
 263                         if (eh == null)
 264                                 return;
 265                         eh (this, args);
 266                 }
 267         }
 268 }