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//------------------------------------------------------------------------------
// <copyright file="StateBag.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI {
using System.Text;
using System.IO;
using System.Collections;
using System.Collections.Specialized;
using System.Reflection;
using System.Web.Util;
/*
* The StateBag class is a helper class used to manage state of properties.
* The class stores name/value pairs as string/object and tracks modifications of
* properties after being 'marked'. This class is used as the primary storage
* mechanism for all HtmlControls and WebControls.
*/
/// <devdoc>
/// <para>Manages the state of Web Forms control properties. This
/// class stores attribute/value pairs as string/object and tracks changes to these
/// attributes, which are treated as properties, after the Page.Init
/// method is executed for a
/// page request. </para>
/// <note type="note">
/// Only values changed after Page.Init
/// has executed are persisted to the page's view state.
/// </note>
/// </devdoc>
public sealed class StateBag : IStateManager, IDictionary {
private IDictionary bag;
private bool marked;
private bool ignoreCase;
/*
* Constructs an StateBag
*/
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.StateBag'/> class.</para>
/// </devdoc>
public StateBag() : this(false) {
}
/*
* Constructs an StateBag
*/
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.StateBag'/> class that allows stored state
/// values to be case-insensitive.</para>
/// </devdoc>
public StateBag(bool ignoreCase) {
marked = false;
this.ignoreCase = ignoreCase;
bag = CreateBag();
}
/*
* Return count of number of StateItems in the bag.
*/
/// <devdoc>
/// <para>Indicates the number of items in the <see cref='System.Web.UI.StateBag'/> object. This property is
/// read-only.</para>
/// </devdoc>
public int Count {
get {
return bag.Count;
}
}
/*
* Returns a collection of keys.
*/
/// <devdoc>
/// <para>Indicates a collection of keys representing the items in the <see cref='System.Web.UI.StateBag'/> object.
/// This property is read-only.</para>
/// </devdoc>
public ICollection Keys {
get {
return bag.Keys;
}
}
/*
* Returns a collection of values.
*/
/// <devdoc>
/// <para>Indicates a collection of view state values in the <see cref='System.Web.UI.StateBag'/> object.
/// This property is read-only.</para>
/// </devdoc>
public ICollection Values {
get {
return bag.Values;
}
}
/*
* Get or set value of a StateItem.
* A set will automatically add a new StateItem for a
* key which is not already in the bag. A set to null
* will remove the item if set before mark, otherwise
* a null set will be saved to allow tracking of state
* removed after mark.
*/
/// <devdoc>
/// <para> Indicates the value of an item stored in the
/// <see langword='StateBag'/>
/// object. Setting this property with a key not already stored in the StateBag will
/// add an item to the bag. If you set this property to <see langword='null'/> before
/// the TrackState method is called on an item will remove it from the bag. Otherwise,
/// when you set this property to <see langword='null'/>
/// the key will be saved to allow tracking of the item's state.</para>
/// </devdoc>
public object this[string key] {
get {
if (String.IsNullOrEmpty(key))
throw ExceptionUtil.ParameterNullOrEmpty("key");
StateItem item = bag[key] as StateItem;
if (item != null)
return item.Value;
return null;
}
set {
Add(key,value);
}
}
/*
* Private implementation of IDictionary item accessor
*/
/// <internalonly/>
object IDictionary.this[object key] {
get { return this[(string) key]; }
set { this[(string) key] = value; }
}
private IDictionary CreateBag() {
return new HybridDictionary(ignoreCase);
}
/*
* Add a new StateItem or update an existing StateItem in the bag.
*/
/// <devdoc>
/// <para>[To be supplied.]</para>
/// </devdoc>
public StateItem Add(string key,object value) {
if (String.IsNullOrEmpty(key))
throw ExceptionUtil.ParameterNullOrEmpty("key");
StateItem item = bag[key] as StateItem;
if (item == null) {
if (value != null || marked) {
item = new StateItem(value);
bag.Add(key,item);
}
}
else {
if (value == null && !marked) {
bag.Remove(key);
}
else {
item.Value = value;
}
}
if (item != null && marked) {
item.IsDirty = true;
}
return item;
}
/*
* Private implementation of IDictionary Add
*/
/// <internalonly/>
void IDictionary.Add(object key,object value) {
Add((string) key, value);
}
/*
* Clear all StateItems from the bag.
*/
/// <devdoc>
/// <para>Removes all controls from the <see cref='System.Web.UI.StateBag'/> object.</para>
/// </devdoc>
public void Clear() {
bag.Clear();
}
/*
* Get an enumerator for the StateItems.
*/
/// <devdoc>
/// <para>Returns an enumerator that iterates over the key/value pairs stored in
/// the <see langword='StateBag'/>.</para>
/// </devdoc>
public IDictionaryEnumerator GetEnumerator() {
return bag.GetEnumerator();
}
/*
* Return the dirty flag of the state item.
* Returns false if there is not an item for given key.
*/
/// <devdoc>
/// <para>Checks an item stored in the <see langword='StateBag'/> to see if it has been
/// modified.</para>
/// </devdoc>
public bool IsItemDirty(string key) {
StateItem item = bag[key] as StateItem;
if (item != null)
return item.IsDirty;
return false;
}
/*
* Return true if 'marked' and state changes are being tracked.
*/
/// <devdoc>
/// <para>Determines if state changes in the StateBag object's store are being tracked.</para>
/// </devdoc>
internal bool IsTrackingViewState {
get {
return marked;
}
}
/*
* Restore state that was previously saved via SaveViewState.
*/
/// <devdoc>
/// <para>Loads the specified previously saved state information</para>
/// </devdoc>
internal void LoadViewState(object state) {
if (state != null) {
ArrayList data = (ArrayList)state;
for (int i = 0; i < data.Count; i += 2) {
#if OBJECTSTATEFORMATTER
string key = ((IndexedString)data[i]).Value;
#else
string key = (string)data[i];
#endif
object value = data[i + 1];
Add(key, value);
}
}
}
/*
* Start tracking state changes after "mark".
*/
/// <devdoc>
/// <para>Initiates the tracking of state changes for items stored in the
/// <see langword='StateBag'/> object.</para>
/// </devdoc>
internal void TrackViewState() {
marked = true;
}
/*
* Remove a StateItem from the bag altogether regardless of marked.
* Used internally by controls.
*/
/// <devdoc>
/// <para>Removes the specified item from the <see cref='System.Web.UI.StateBag'/> object.</para>
/// </devdoc>
public void Remove(string key) {
bag.Remove(key);
}
/*
* Private implementation of IDictionary Remove
*/
/// <internalonly/>
void IDictionary.Remove(object key) {
Remove((string) key);
}
/*
* Return object containing state that has been modified since "mark".
* Returns null if there is no modified state.
*/
/// <devdoc>
/// <para>Returns an object that contains all state changes for items stored in the
/// <see langword='StateBag'/> object.</para>
/// </devdoc>
internal object SaveViewState() {
ArrayList data = null;
//
if (bag.Count != 0) {
IDictionaryEnumerator e = bag.GetEnumerator();
while (e.MoveNext()) {
StateItem item = (StateItem)(e.Value);
if (item.IsDirty) {
if (data == null) {
data = new ArrayList();
}
#if OBJECTSTATEFORMATTER
data.Add(new IndexedString((string)e.Key));
#else
data.Add(e.Key);
#endif
data.Add(item.Value);
}
}
}
return data;
}
/// <devdoc>
/// Sets the dirty state of all item values currently in the StateBag.
/// </devdoc>
public void SetDirty(bool dirty) {
if (bag.Count != 0) {
foreach (StateItem item in bag.Values) {
item.IsDirty = dirty;
}
}
}
/*
* Internal method for setting dirty flag on a state item.
* Used internallly to prevent state management of certain properties.
*/
/// <internalonly/>
/// <devdoc>
/// </devdoc>
public void SetItemDirty(string key,bool dirty) {
StateItem item = bag[key] as StateItem;
if (item != null) {
item.IsDirty = dirty;
}
}
/// <internalonly/>
bool IDictionary.IsFixedSize {
get { return false; }
}
/// <internalonly/>
bool IDictionary.IsReadOnly {
get { return false; }
}
/// <internalonly/>
bool ICollection.IsSynchronized {
get { return false;}
}
/// <internalonly/>
object ICollection.SyncRoot {
get {return this; }
}
/// <internalonly/>
bool IDictionary.Contains(object key) {
return bag.Contains((string) key);
}
/// <internalonly/>
IEnumerator IEnumerable.GetEnumerator() {
return ((IDictionary)this).GetEnumerator();
}
/// <internalonly/>
void ICollection.CopyTo(Array array, int index) {
Values.CopyTo(array, index);
}
/*
* Return true if tracking state changes.
* Method of private interface, IStateManager.
*/
/// <internalonly/>
bool IStateManager.IsTrackingViewState {
get {
return IsTrackingViewState;
}
}
/*
* Load previously saved state.
* Method of private interface, IStateManager.
*/
/// <internalonly/>
void IStateManager.LoadViewState(object state) {
LoadViewState(state);
}
/*
* Start tracking state changes.
* Method of private interface, IStateManager.
*/
/// <internalonly/>
void IStateManager.TrackViewState() {
TrackViewState();
}
/*
* Return object containing state changes.
* Method of private interface, IStateManager.
*/
/// <internalonly/>
object IStateManager.SaveViewState() {
return SaveViewState();
}
}
}
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