Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/UI/HtmlControls/HtmlInputHidden.cs

@@ -0,0 +1,156 @@
+//------------------------------------------------------------------------------
+// <copyright file="HtmlInputHidden.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+/*
+ * HtmlInputHidden.cs
+ *
+ * Copyright (c) 2000 Microsoft Corporation
+ */
+
+namespace System.Web.UI.HtmlControls {
+    using System.ComponentModel;
+    using System;
+    using System.Collections;
+    using System.Collections.Specialized;
+    using System.Web;
+    using System.Web.UI;
+    using System.Security.Permissions;
+
+
+/// <devdoc>
+///    <para>
+///       The <see langword='HtmlInputHidden'/> class defines the methods, properties,
+///       and events of the HtmlInputHidden control. This class allows programmatic access
+///       to the HTML &lt;input type=hidden&gt; element on the server.
+///    </para>
+/// </devdoc>
+    [
+    DefaultEvent("ServerChange"),
+    SupportsEventValidation,
+    ]
+    public class HtmlInputHidden : HtmlInputControl, IPostBackDataHandler {
+
+        private static readonly object EventServerChange = new object();
+
+        /*
+         * Creates an intrinsic Html INPUT type=hidden control.
+         */
+
+        public HtmlInputHidden() : base("hidden") {
+        }
+
+
+        /// <devdoc>
+        ///    <para>
+        ///       Occurs when the <see langword='HtmlInputHidden'/> control
+        ///       is changed on the server.
+        ///    </para>
+        /// </devdoc>
+        [
+        WebCategory("Action"),
+        WebSysDescription(SR.HtmlInputHidden_OnServerChange)
+        ]
+        public event EventHandler ServerChange {
+            add {
+                Events.AddHandler(EventServerChange, value);
+            }
+            remove {
+                Events.RemoveHandler(EventServerChange, value);
+            }
+        }
+
+        /*
+         * Method used to raise the OnServerChange event.
+         */
+
+        /// <devdoc>
+        ///    <para>
+        ///       Raised on the server when the <see langword='HtmlInputHidden'/> control
+        ///       changes between postback requests.
+        ///    </para>
+        /// </devdoc>
+        protected virtual void OnServerChange(EventArgs e) {
+            EventHandler handler = (EventHandler)Events[EventServerChange];
+            if (handler != null) handler(this, e);
+        }
+
+        /*
+         *
+         */
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// </devdoc>
+        protected internal override void OnPreRender(EventArgs e) {
+            base.OnPreRender(e);
+
+            // if no change handler, no need to save posted property
+            if (!Disabled) {
+                if (Events[EventServerChange] == null) {
+                    ViewState.SetItemDirty("value",false);
+                }
+
+                if (Page != null) {
+                    Page.RegisterEnabledControl(this);
+                }
+            }
+        }
+
+        /*
+         * Method of IPostBackDataHandler interface to process posted data.
+         * InputText process a newly posted value.
+         */
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// </devdoc>
+        bool IPostBackDataHandler.LoadPostData(string postDataKey, NameValueCollection postCollection) {
+            return LoadPostData(postDataKey, postCollection);
+        }
+
+        protected virtual bool LoadPostData(string postDataKey, NameValueCollection postCollection) {
+            string current = Value;
+            string text = postCollection.GetValues(postDataKey)[0];
+
+            if (!current.Equals(text)) {
+                ValidateEvent(postDataKey);
+
+                Value = text;
+                return true;
+            }
+
+            return false;
+        }
+
+        protected override void RenderAttributes(HtmlTextWriter writer) {
+            base.RenderAttributes(writer);
+
+            if (Page != null) {
+                Page.ClientScript.RegisterForEventValidation(RenderedNameAttribute);
+            }
+        }
+
+        /*
+         * Method of IPostBackDataHandler interface which is invoked whenever posted data
+         * for a control has changed.  TextBox fires an OnTextChanged event.
+         */
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// </devdoc>
+        void IPostBackDataHandler.RaisePostDataChangedEvent() {
+            RaisePostDataChangedEvent();
+        }
+
+
+        /// <internalonly/>
+        /// <devdoc>
+        /// </devdoc>
+        protected virtual void RaisePostDataChangedEvent() {
+            OnServerChange(EventArgs.Empty);
+        }
+    }
+}