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//------------------------------------------------------------------------------
// <copyright file="listitem.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI.WebControls {
using System;
using System.Collections;
using System.ComponentModel;
using System.Globalization;
using AttributeCollection = System.Web.UI.AttributeCollection;
using System.Web.Util;
/// <devdoc>
/// <para>Interacts with the parser to build a <see cref='System.Web.UI.WebControls.ListItem'/> control.</para>
/// </devdoc>
public class ListItemControlBuilder : ControlBuilder {
public override bool AllowWhitespaceLiterals() {
return false;
}
public override bool HtmlDecodeLiterals() {
// ListItem text gets rendered as an encoded attribute value.
// At parse time text specified as an attribute gets decoded, and so text specified as a
// literal needs to go through the same process.
return true;
}
}
/// <devdoc>
/// <para>Constructs a list item control and defines
/// its properties. This class cannot be inherited.</para>
/// </devdoc>
[
ControlBuilderAttribute(typeof(ListItemControlBuilder)),
TypeConverterAttribute(typeof(ExpandableObjectConverter)),
ParseChildren(true, "Text"),
]
public sealed class ListItem : IStateManager, IParserAccessor, IAttributeAccessor {
private bool selected;
private bool marked;
private bool textisdirty;
private bool valueisdirty;
private bool enabled;
private bool enabledisdirty;
private string text;
private string value;
private AttributeCollection _attributes;
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.ListItem'/> class.</para>
/// </devdoc>
public ListItem() : this(null, null) {
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.ListItem'/> class with the specified text data.</para>
/// </devdoc>
public ListItem(string text) : this(text, null) {
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.ListItem'/> class with the specified text data.</para>
/// </devdoc>
public ListItem(string text, string value) : this(text, value, true) {
}
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.ListItem'/> class with the
/// specified text and value data.</para>
/// </devdoc>
public ListItem(string text, string value, bool enabled) {
this.text = text;
this.value = value;
this.enabled = enabled;
}
/// <devdoc>
/// <para>Gets the collection of attribute name/value pairs expressed on the list item
/// control but not supported by the control's strongly typed properties.</para>
/// </devdoc>
[
Browsable(false),
DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
]
public AttributeCollection Attributes {
get {
if (_attributes == null)
_attributes = new AttributeCollection(new StateBag(true));
return _attributes;
}
}
/// <devdoc>
/// Internal property used to manage dirty state of ListItem.
/// </devdoc>
internal bool Dirty {
get {
return (textisdirty || valueisdirty || enabledisdirty);
}
set {
textisdirty = value;
valueisdirty = value;
enabledisdirty = value;
}
}
[
DefaultValue(true)
]
public bool Enabled {
get {
return enabled;
}
set {
enabled = value;
if (((IStateManager)this).IsTrackingViewState)
enabledisdirty = true;
}
}
internal bool HasAttributes {
get {
return _attributes != null && _attributes.Count > 0;
}
}
/// <devdoc>
/// <para>Specifies a value indicating whether the
/// item is selected.</para>
/// </devdoc>
[
DefaultValue(false),
TypeConverter(typeof(MinimizableAttributeTypeConverter))
]
public bool Selected {
get {
return selected;
}
set {
selected = value;
}
}
/// <devdoc>
/// <para>Gets or sets the display text of the list
/// item control.</para>
/// </devdoc>
[
Localizable(true),
DefaultValue(""),
PersistenceMode(PersistenceMode.EncodedInnerDefaultProperty)
]
public string Text {
get {
if (text != null)
return text;
if (value != null)
return value;
return String.Empty;
}
set {
text = value;
if (((IStateManager)this).IsTrackingViewState)
textisdirty = true;
}
}
/// <devdoc>
/// <para>Gets or sets the value content of the list item control.</para>
/// </devdoc>
[
Localizable(true),
DefaultValue("")
]
public string Value {
get {
if (value != null)
return value;
if (text != null)
return text;
return String.Empty;
}
set {
this.value = value;
if (((IStateManager)this).IsTrackingViewState)
valueisdirty =true;
}
}
/// <internalonly/>
public override int GetHashCode() {
return HashCodeCombiner.CombineHashCodes(Value.GetHashCode(), Text.GetHashCode());
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
public override bool Equals(object o) {
ListItem other = o as ListItem;
if (other != null) {
return Value.Equals(other.Value) && Text.Equals(other.Text);
}
return false;
}
/// <devdoc>
/// <para>Creates a <see cref='System.Web.UI.WebControls.ListItem'/> from the specified string.</para>
/// </devdoc>
public static ListItem FromString(string s) {
return new ListItem(s);
}
/// <internalonly/>
/// <devdoc>
/// </devdoc>
public override string ToString() {
return this.Text;
}
/// <internalonly/>
/// <devdoc>
/// Return true if tracking state changes.
/// Method of private interface, IStateManager.
/// </devdoc>
bool IStateManager.IsTrackingViewState {
get {
return marked;
}
}
/// <internalonly/>
void IStateManager.LoadViewState(object state) {
LoadViewState(state);
}
internal void LoadViewState(object state) {
if (state != null) {
if (state is Triplet) {
Triplet t = (Triplet) state;
if (t.First != null) {
Text = (string) t.First;
}
if (t.Second != null) {
Value = (string) t.Second;
}
if (t.Third != null) {
try {
Enabled = (bool) t.Third;
}
catch {
}
}
}
else if (state is Pair) {
Pair p = (Pair) state;
if (p.First != null)
Text = (string) p.First;
Value = (string) p.Second;
}
else
Text = (string) state;
}
}
/// <internalonly/>
void IStateManager.TrackViewState() {
TrackViewState();
}
internal void TrackViewState() {
marked = true;
}
internal void RenderAttributes(HtmlTextWriter writer) {
if (_attributes != null) {
_attributes.AddAttributes(writer);
}
}
/// <internalonly/>
object IStateManager.SaveViewState() {
return SaveViewState();
}
internal object SaveViewState() {
string text = null;
string value = null;
if(textisdirty) {
text = Text;
}
if(valueisdirty) {
value = Value;
}
if(enabledisdirty) {
return new Triplet(text, value, Enabled);
}
else if(valueisdirty) {
return new Pair(text, value);
}
else if(textisdirty) {
return text;
}
return null;
}
/// <internalonly/>
/// <devdoc>
/// Returns the attribute value of the list item control
/// having the specified attribute name.
/// </devdoc>
string IAttributeAccessor.GetAttribute(string name) {
return Attributes[name];
}
/// <internalonly/>
/// <devdoc>
/// <para>Sets an attribute of the list
/// item control with the specified name and value.</para>
/// </devdoc>
void IAttributeAccessor.SetAttribute(string name, string value) {
Attributes[name] = value;
}
/// <internalonly/>
/// <devdoc>
/// <para> Allows the <see cref='System.Web.UI.WebControls.ListItem.Text'/>
/// property to be persisted as inner content.</para>
/// </devdoc>
void IParserAccessor.AddParsedSubObject(object obj) {
if (obj is LiteralControl) {
Text = ((LiteralControl)obj).Text;
}
else {
if (obj is DataBoundLiteralControl) {
throw new HttpException(SR.GetString(SR.Control_Cannot_Databind, "ListItem"));
}
else {
throw new HttpException(SR.GetString(SR.Cannot_Have_Children_Of_Type, "ListItem", obj.GetType().Name.ToString(CultureInfo.InvariantCulture)));
}
}
}
/// <devdoc>
/// Do not change the signature or remove this method. It is called via reflection
/// to support correct serialization behavior for Text and Value which are
/// implemented as dependent properties.
/// </devdoc>
private void ResetText() {
Text = null;
}
/// <devdoc>
/// Do not change the signature or remove this method. It is called via reflection
/// to support correct serialization behavior for Text and Value which are
/// implemented as dependent properties.
/// </devdoc>
private void ResetValue() {
Value = null;
}
/// <devdoc>
/// Do not change the signature or remove this method. It is called via reflection
/// to support correct serialization behavior for Text and Value which are
/// implemented as dependent properties.
/// </devdoc>
private bool ShouldSerializeText() {
return (text != null) && (text.Length != 0);
}
/// <devdoc>
/// Do not change the signature or remove this method. It is called via reflection
/// to support correct serialization behavior for Text and Value which are
/// implemented as dependent properties.
/// </devdoc>
private bool ShouldSerializeValue() {
return (value != null) && (value.Length != 0);
}
}
}
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