Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web.Mobile/UI/MobileControls/Design/Util/UnsettableComboBox.cs

@@ -0,0 +1,137 @@
+//------------------------------------------------------------------------------
+// <copyright file="UnsettableComboBox.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI.Design.MobileControls.Util
+{
+    using System;
+    using System.Collections;
+    using System.ComponentModel;
+    using System.Diagnostics;
+    using System.Drawing;
+    using System.Windows.Forms;
+
+    //   Standard combobox with a "Not Set" item as the first item in its dropdown.
+    //   It also automatically blanks out the "Not Set" item on losing focus.
+    [
+        System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand,
+        Flags=System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)
+    ]
+    [Obsolete("The System.Web.Mobile.dll assembly has been deprecated and should no longer be used. For information about how to develop ASP.NET mobile applications, see http://go.microsoft.com/fwlink/?LinkId=157231.")]
+    internal class UnsettableComboBox : ComboBox 
+    {
+        private String notSetText;
+        private String notSetCompactText;
+
+        internal UnsettableComboBox() 
+        {
+            notSetText = SR.GetString(SR.UnsettableComboBox_NotSetText);
+            notSetCompactText = SR.GetString(SR.UnsettableComboBox_NotSetCompactText);
+        }
+
+        internal String NotSetText 
+        {
+            get 
+            {
+                return notSetText;
+            }
+            set 
+            {
+                notSetText = value;
+            }
+        }
+
+        internal String NotSetCompactText 
+        {
+            get 
+            {
+                return notSetCompactText;
+            }
+            set 
+            {
+                notSetCompactText = value;
+            }
+        }
+
+        public override String Text 
+        {
+            get 
+            {
+                // handle DropDown styles in Templating Options dialog
+                // if (this.SelectedIndex == 0) || (this.SelectedIndex == -1))
+                if (this.SelectedIndex == 0)
+                {
+                    return String.Empty;
+                }
+                else
+                {
+                    return base.Text;
+                }
+            }
+
+            set 
+            {
+                if (value == notSetCompactText)
+                {
+                    base.Text = String.Empty;
+                }
+                else
+                {
+                    base.Text = value;
+                }
+            }
+        }
+
+        internal void AddItem(Object item) 
+        {
+            EnsureNotSetItem();
+            Items.Add(item);
+        }
+
+        internal void EnsureNotSetItem() 
+        {
+            if (Items.Count == 0) 
+            {
+                Items.Add(notSetText);
+            }
+        }
+
+#if UNUSED_CODE
+        internal bool IsSet() 
+        {
+            return SelectedIndex > 0;
+        }
+#endif
+        protected override void OnLostFocus(EventArgs e) 
+        {
+            base.OnLostFocus(e);
+
+            if (SelectedIndex == 0)
+            {
+                SelectedIndex = -1;
+            }
+        }
+
+        protected override void SetItemsCore(IList values)
+        {
+            Items.Clear();
+            
+            if (!DesignMode) 
+            {
+                Items.Add(notSetText);
+            }
+            
+            // Unfortunately. the interfaces between SetItemsCore and
+            // AddItemsCore are mismatched as of 3106.
+            ArrayList items = new ArrayList();
+            foreach(Object item in values)
+            {
+                items.Add(item);
+            }
+            
+            base.AddItemsCore(items.ToArray());
+        }
+    }
+}