DataSourceSelectArguments.cs :  » 2.6.4-mono-.net-core » System.Web » System » Web » UI » C# / CSharp Open Source

//
// System.Web.UI.DataSourceSelectArguments.cs
//
// Author:
//   Sanjay Gupta <gsanjay@novell.com>
//
// (C) 2004-2010 Novell, Inc (http://www.novell.com)
//

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;

namespace System.Web.UI{
  public sealed class DataSourceSelectArguments
  {
    string sortExpression;
    int startingRowIndex;
    int maxRows;
    bool getTotalRowCount;
    int totalRowCount = -1;
    DataSourceCapabilities dsc = DataSourceCapabilities.None;

    // MSDN: Gets a DataSourceSelectArguments object with the sort expression set to Empty. 
    public static DataSourceSelectArguments Empty {
      get {
        return new DataSourceSelectArguments ();
      }
    }

    public DataSourceSelectArguments ()
    {
    }

    public DataSourceSelectArguments (string sortExpression)
    {
      this.sortExpression = sortExpression;
    }

    public DataSourceSelectArguments (int startingRowIndex, int maxRows)
    {
      this.startingRowIndex = startingRowIndex;
      this.maxRows = maxRows;
    }

    public DataSourceSelectArguments (string sortExpression, int startingRowIndex, int maxRows)
    {
      this.sortExpression = sortExpression; 
      this.startingRowIndex = startingRowIndex;
      this.maxRows = maxRows;
    }

    public void AddSupportedCapabilities (DataSourceCapabilities srcCapabilities)
    {
      this.dsc = this.dsc | srcCapabilities;
    }

    // MSDN: The DataSourceSelectArguments class overrides the Object.Equals method to test 
    // equality using the various properties of the objects. If the MaximumRows, 
    // RetrieveTotalRowCount, SortExpression, StartRowIndex, and TotalRowCount properties 
    // are all equal in value, the Equals(Object) method returns true.
    public override bool Equals (object obj)
    {
      DataSourceSelectArguments args = obj as DataSourceSelectArguments;
      if (args == null)
        return false;

      return (this.SortExpression == args.SortExpression &&
        this.StartRowIndex == args.StartRowIndex &&
        this.MaximumRows == args.MaximumRows &&
        this.RetrieveTotalRowCount == args.RetrieveTotalRowCount &&
        this.TotalRowCount == args.TotalRowCount);
    }

    public override int GetHashCode ()
    {
      int hash = SortExpression != null ? SortExpression.GetHashCode() : 0;
      return hash ^ StartRowIndex ^ MaximumRows ^ RetrieveTotalRowCount.GetHashCode() ^ TotalRowCount;
    }

    // The RaiseUnsupportedCapabilitiesError method is used by data-bound controls 
    // to compare additional requested capabilities represented by the properties 
    // of the DataSourceSelectArguments class, such as the ability to sort or page 
    // through a result set, with the capabilities supported by the data source view. 
    // The view calls its own RaiseUnsupportedCapabilityError method for each possible 
    // capability defined in the DataSourceCapabilities enumeration. 
    public void RaiseUnsupportedCapabilitiesError (DataSourceView view)
    {
      DataSourceCapabilities requestedCaps = RequestedCapabilities;
      DataSourceCapabilities notSupportedCaps = (requestedCaps ^ dsc) & requestedCaps;
      if (notSupportedCaps == DataSourceCapabilities.None)
        return;

      if ((notSupportedCaps & DataSourceCapabilities.RetrieveTotalRowCount) > 0)
        notSupportedCaps = DataSourceCapabilities.RetrieveTotalRowCount;
      else if ((notSupportedCaps & DataSourceCapabilities.Page) > 0)
        notSupportedCaps = DataSourceCapabilities.Page;

      view.RaiseUnsupportedCapabilityError (notSupportedCaps);
    }

    DataSourceCapabilities RequestedCapabilities {
      get {
        DataSourceCapabilities caps = DataSourceCapabilities.None;
        if (!String.IsNullOrEmpty (SortExpression))
          caps |= DataSourceCapabilities.Sort;
        if (RetrieveTotalRowCount)
          caps |= DataSourceCapabilities.RetrieveTotalRowCount;
        if (StartRowIndex > 0 || MaximumRows > 0)
          caps |= DataSourceCapabilities.Page;
        return caps;
      }
    }

    public int MaximumRows {
      get { return this.maxRows; }
      set { this.maxRows = value; }
    }

    public bool RetrieveTotalRowCount  {
      get { return this.getTotalRowCount; }
      set { this.getTotalRowCount = value; }
    }

    public string SortExpression {
      get {
        if (sortExpression == null)
          return String.Empty;
        return this.sortExpression;
      }
      set { this.sortExpression = value; }
    }

    public int StartRowIndex {
      get { return this.startingRowIndex; }
      set { this.startingRowIndex = value; }
    }

    public int TotalRowCount {
      get { return this.totalRowCount; }
      set { this.totalRowCount = value; }
    }
  }
}