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//------------------------------------------------------------------------------
// <copyright file="HyperLink.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//------------------------------------------------------------------------------
namespace System.Web.UI.WebControls {
using System;
using System.ComponentModel;
using System.Drawing.Design;
using System.Web;
using System.Web.UI;
using System.Web.Util;
/// <devdoc>
/// <para>Interacts with the parser to build a <see cref='System.Web.UI.WebControls.HyperLink'/>.</para>
/// </devdoc>
public class HyperLinkControlBuilder : ControlBuilder {
/// <devdoc>
/// <para>Gets a value to indicate whether or not white spaces are allowed in literals for this control. This
/// property is read-only.</para>
/// </devdoc>
public override bool AllowWhitespaceLiterals() {
return false;
}
}
/// <devdoc>
/// <para>Creates a link for the browser to navigate to another page.</para>
/// </devdoc>
[
ControlBuilderAttribute(typeof(HyperLinkControlBuilder)),
DataBindingHandler("System.Web.UI.Design.HyperLinkDataBindingHandler, " + AssemblyRef.SystemDesign),
DefaultProperty("Text"),
Designer("System.Web.UI.Design.WebControls.HyperLinkDesigner, " + AssemblyRef.SystemDesign),
ToolboxData("<{0}:HyperLink runat=\"server\">HyperLink</{0}:HyperLink>"),
ParseChildren(false)
]
public class HyperLink : WebControl {
private bool _textSetByAddParsedSubObject = false;
/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Web.UI.WebControls.HyperLink'/> class.</para>
/// </devdoc>
public HyperLink() : base(HtmlTextWriterTag.A) {
}
/// <devdoc>
/// <para>Gets or sets the URL reference to an image to display as an alternative to plain text for the
/// hyperlink.</para>
/// </devdoc>
[
Bindable(true),
WebCategory("Appearance"),
DefaultValue(""),
Editor("System.Web.UI.Design.ImageUrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
UrlProperty(),
WebSysDescription(SR.HyperLink_ImageUrl)
]
public virtual string ImageUrl {
get {
string s = (string)ViewState["ImageUrl"];
return((s == null) ? String.Empty : s);
}
set {
ViewState["ImageUrl"] = value;
}
}
[
WebCategory("Appearance"),
DefaultValue(typeof(Unit), ""),
WebSysDescription(SR.HyperLink_ImageHeight)
]
public virtual Unit ImageHeight {
get {
object o = ViewState["ImageHeight"];
if (o != null) {
return (Unit)o;
}
return Unit.Empty;
}
set {
ViewState["ImageHeight"] = value;
}
}
[
WebCategory("Appearance"),
DefaultValue(typeof(Unit), ""),
WebSysDescription(SR.HyperLink_ImageWidth)
]
public virtual Unit ImageWidth {
get {
object o = ViewState["ImageWidth"];
if (o != null) {
return (Unit)o;
}
return Unit.Empty;
}
set {
ViewState["ImageWidth"] = value;
}
}
/// <devdoc>
/// <para>Gets or sets the URL reference to navigate to when the hyperlink is clicked.</para>
/// </devdoc>
[
Bindable(true),
WebCategory("Navigation"),
DefaultValue(""),
Editor("System.Web.UI.Design.UrlEditor, " + AssemblyRef.SystemDesign, typeof(UITypeEditor)),
UrlProperty(),
WebSysDescription(SR.HyperLink_NavigateUrl)
]
public string NavigateUrl {
get {
string s = (string)ViewState["NavigateUrl"];
return((s == null) ? String.Empty : s);
}
set {
ViewState["NavigateUrl"] = value;
}
}
public override bool SupportsDisabledAttribute {
get {
return RenderingCompatibility < VersionUtil.Framework40;
}
}
internal override bool RequiresLegacyRendering {
get {
return true;
}
}
/// <devdoc>
/// <para>Gets or sets the target window or frame the contents of
/// the <see cref='System.Web.UI.WebControls.HyperLink'/> will be displayed into when clicked.</para>
/// </devdoc>
[
WebCategory("Navigation"),
DefaultValue(""),
WebSysDescription(SR.HyperLink_Target),
TypeConverter(typeof(TargetConverter))
]
public string Target {
get {
string s = (string)ViewState["Target"];
return((s == null) ? String.Empty : s);
}
set {
ViewState["Target"] = value;
}
}
/// <devdoc>
/// <para>
/// Gets or sets the text displayed for the <see cref='System.Web.UI.WebControls.HyperLink'/>.</para>
/// </devdoc>
[
Localizable(true),
Bindable(true),
WebCategory("Appearance"),
DefaultValue(""),
WebSysDescription(SR.HyperLink_Text),
PersistenceMode(PersistenceMode.InnerDefaultProperty)
]
public virtual string Text {
get {
object o = ViewState["Text"];
return((o == null) ? String.Empty : (string)o);
}
set {
if (HasControls()) {
Controls.Clear();
}
ViewState["Text"] = value;
}
}
/// <internalonly/>
/// <devdoc>
/// <para>Adds the attribututes of the a <see cref='System.Web.UI.WebControls.HyperLink'/> to the output
/// stream for rendering.</para>
/// </devdoc>
protected override void AddAttributesToRender(HtmlTextWriter writer) {
if (Enabled && !IsEnabled && SupportsDisabledAttribute) {
// We need to do the cascade effect on the server, because the browser
// only renders as disabled, but doesn't disable the functionality.
writer.AddAttribute(HtmlTextWriterAttribute.Disabled, "disabled");
}
base.AddAttributesToRender(writer);
string s = NavigateUrl;
if ((s.Length > 0) && IsEnabled) {
string resolvedUrl = ResolveClientUrl(s);
writer.AddAttribute(HtmlTextWriterAttribute.Href, resolvedUrl);
}
s = Target;
if (s.Length > 0) {
writer.AddAttribute(HtmlTextWriterAttribute.Target, s);
}
}
protected override void AddParsedSubObject(object obj) {
if (HasControls()) {
base.AddParsedSubObject(obj);
}
else {
if (obj is LiteralControl) {
if (_textSetByAddParsedSubObject) {
Text += ((LiteralControl)obj).Text;
}
else {
Text = ((LiteralControl)obj).Text;
}
_textSetByAddParsedSubObject = true;
}
else {
string currentText = Text;
if (currentText.Length != 0) {
//Text was set to String.Empty, which cause clearing all child controls when LoadViewState(DevDiv Bugs 159505)
Text = null;
base.AddParsedSubObject(new LiteralControl(currentText));
}
base.AddParsedSubObject(obj);
}
}
}
/// <internalonly/>
/// <devdoc>
/// Load previously saved state.
/// Overridden to synchronize Text property with LiteralContent.
/// </devdoc>
protected override void LoadViewState(object savedState) {
if (savedState != null) {
base.LoadViewState(savedState);
string s = (string)ViewState["Text"];
// Dev10 703061 If Text is set, we want to clear out any child controls, but not dirty viewstate
if (s != null && HasControls()) {
Controls.Clear();
}
}
}
/// <internalonly/>
/// <devdoc>
/// <para>Displays the <see cref='System.Web.UI.WebControls.HyperLink'/> on a page.</para>
/// </devdoc>
protected internal override void RenderContents(HtmlTextWriter writer) {
string s = ImageUrl;
if (s.Length > 0) {
Image img = new Image();
// NOTE: The Url resolution happens right here, because the image is not parented
// and will not be able to resolve when it tries to do so.
img.ImageUrl = ResolveClientUrl(s);
img.UrlResolved = true;
img.GenerateEmptyAlternateText = true;
if (ImageHeight != Unit.Empty) {
img.Height = ImageHeight;
}
if (ImageWidth != Unit.Empty) {
img.Width = ImageWidth;
}
s = ToolTip;
if (s.Length != 0) {
img.ToolTip = s;
}
s = Text;
if (s.Length != 0) {
img.AlternateText = s;
}
img.RenderControl(writer);
}
else {
if (HasRenderingData()) {
base.RenderContents(writer);
}
else {
writer.Write(Text);
}
}
}
}
}
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