using System;
using System.Collections;
using System.Web.UI;
namespace Utils
{
#region UserControlManager
public sealed class UserControlViewStateManager : Page
{
private struct ControlClass : IComparable
{
public Int32 OrdinalIndex;
public String ControlID;
public Type Type;
public Int32 CompareTo(Object obj)
{
ControlClass controlClass = (ControlClass) obj;
return (this.OrdinalIndex.CompareTo(controlClass.OrdinalIndex));
}
}
private ArrayList controlsTable;
private Int32 LastOrdinalIndex;
private String InstanceSessionID;
/// <summary>
/// .ctor()
/// </summary>
public UserControlViewStateManager(String InstanceSessionID)
{
this.InstanceSessionID = InstanceSessionID;
LoadFromSession();
}
/// <summary>
/// Add the control to UserControlViewStateManager
/// </summary>
/// <param name="control">Control object</param>
public void AddControl(Control control)
{
if (control == null)
{
throw new NullReferenceException();
}
if (control.ID == null || control.ID.Equals(String.Empty))
{
throw new Exception("controlID must be set.");
}
if (controlsTable == null)
{
controlsTable = new ArrayList();
LastOrdinalIndex = 0;
}
ControlClass newControl = new ControlClass();
Boolean IsControlFound = false;
if (control.ID != null && !control.ID.Equals(String.Empty))
{
foreach (ControlClass ctrl in controlsTable)
{
IsControlFound = (ctrl.ControlID.Equals(control.ID));
if (IsControlFound)
{
break;
}
}
if (IsControlFound)
{
throw new Exception(String.Format("A control with this ID [{0}] already exists.", control.ID));
}
else
{
newControl.ControlID = control.ID;
}
}
newControl.OrdinalIndex = LastOrdinalIndex++;
newControl.Type = control.GetType();
controlsTable.Add(newControl);
SaveToSession();
}
/// <summary>
/// Removes the control from UserControlViewStateManager whose ID is passed through the parameter.
/// </summary>
/// <param name="index">Control ID.</param>
public void RemoveControl(String controlID)
{
if (controlID == null || controlID.Equals(String.Empty))
{
throw new Exception("controlID must be provided.");
}
foreach (ControlClass control in controlsTable)
{
if (control.ControlID.Equals(controlID))
{
controlsTable.Remove(control);
break;
}
}
SaveToSession();
}
/// <summary>
/// Removes the control at the specified index of the UserControlViewStateManager.
/// </summary>
/// <param name="index">The zero-based index of the element to remove.</param>
public void RemoveAt(Int32 index)
{
controlsTable.Sort();
if (controlsTable.Count < index + 1)
{
throw new ArgumentOutOfRangeException();
}
controlsTable.RemoveAt(index);
SaveToSession();
}
/// <summary>
/// Re-creates controls already stored in the class
/// </summary>
/// <param name="container">Container object to which controls will be added</param>
public void ReCreateControls(Control container)
{
if (controlsTable == null)
{
return;
}
controlsTable.Sort();
foreach (ControlClass cachedControl in controlsTable)
{
Control control = (Control) Activator.CreateInstance((Type) cachedControl.Type);
control.ID = cachedControl.ControlID;
container.Controls.Add(control);
}
}
/// <summary>
/// Removes all controls
/// </summary>
public void Reset()
{
controlsTable = null;
SaveToSession();
}
#region Session handling routines
/// <summary>
/// Loads Helper-related data already stored in session
/// </summary>
private void LoadFromSession()
{
if (Session[InstanceSessionID] is ArrayList)
{
controlsTable = (ArrayList) Session[InstanceSessionID];
if (Session[InstanceSessionID + "LastOrdinalIndex"] is Int32)
{
LastOrdinalIndex = Convert.ToInt32(Session[InstanceSessionID + "LastOrdinalIndex"].ToString());
}
}
}
/// <summary>
/// Saves Helper-related data to session
/// </summary>
private void SaveToSession()
{
Session[InstanceSessionID] = controlsTable;
Session[InstanceSessionID + "LastOrdinalIndex"] = LastOrdinalIndex;
}
#endregion
}
#endregion
}
