Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/UI/WebControls/ChildTable.cs

@@ -0,0 +1,93 @@
+//------------------------------------------------------------------------------
+// <copyright file="ChildTable.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI.WebControls {
+
+    using System;
+    using System.ComponentModel;
+    using System.Web.UI;
+    using System.Web.Util;
+
+    [
+    ToolboxItem(false),
+    SupportsEventValidation,
+    ]
+
+    /// <internalonly/>
+    /// <devdoc>
+    ///   Used by composite controls that are based on a table, that only render
+    ///   their contents.
+    ///   Used to render out an ID attribute representing the parent composite control
+    ///   if an ID is not actually set on this table.
+    /// </devdoc>
+    internal class ChildTable : Table {
+
+        private int _parentLevel;
+        private string _parentID;
+        private bool _parentIDSet;
+
+
+        /// <internalonly/>
+        internal ChildTable() : this(1) {
+        }
+
+
+        /// <internalonly/>
+        internal ChildTable(int parentLevel) {
+            Debug.Assert(parentLevel >= 1);
+            _parentLevel = parentLevel;
+            _parentIDSet = false;
+        }
+
+        internal ChildTable(string parentID) {
+            _parentID = parentID;
+            _parentIDSet = true;
+        }
+
+
+        /// <internalonly/>
+        protected override void AddAttributesToRender(HtmlTextWriter writer) {
+            base.AddAttributesToRender(writer);
+            string parentID = _parentID;
+
+            if (!_parentIDSet) {
+                parentID = GetParentID();
+            }
+
+            if (parentID != null) {
+                writer.AddAttribute(HtmlTextWriterAttribute.Id, parentID);
+            }
+        }
+
+
+        /// <devdoc>
+        /// Gets the ClientID of the parent whose ID is supposed to be used in the rendering.
+        /// </devdoc>
+        private string GetParentID() {
+            if (ID != null) {
+                return null;
+            }
+
+            Control parent = this;
+            for (int i = 0; i < _parentLevel; i++) {
+                parent = parent.Parent;
+                if (parent == null) {
+                    break;
+                }
+            }
+
+            Debug.Assert(parent != null);
+            if (parent != null) {
+                string id = parent.ID;
+                if (!String.IsNullOrEmpty(id)) {
+                    return parent.ClientID;
+                }
+            }
+
+            return null;
+        }
+    }
+}