Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Web/UI/DataSourceCacheDurationConverter.cs

@@ -0,0 +1,96 @@
+//------------------------------------------------------------------------------
+// <copyright file="DataSourceCacheDurationConverter.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>                                                                
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI {
+
+    using System;
+    using System.Collections;
+    using System.ComponentModel;
+    using System.ComponentModel.Design.Serialization;
+    using System.Globalization;
+    using System.Reflection;
+    using System.Security.Permissions;
+    using System.Web.Util;
+
+
+    /// <devdoc>
+    /// Converts a cache duration such as an integer or the text "Infinite" to a cache duration, where "Infinite" implies zero (0).
+    /// </devdoc>
+    public class DataSourceCacheDurationConverter : Int32Converter {
+        private StandardValuesCollection _values;
+
+
+        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType) {
+            if (sourceType == typeof(string)) {
+                return true;
+            }
+            else {
+                return base.CanConvertFrom(context, sourceType);
+            }
+        }
+
+
+        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value) {
+            if (value == null)
+                return null;
+
+            string stringValue = value as string;
+            if (stringValue != null) {
+                string textValue = stringValue.Trim();
+                if (textValue.Length == 0) {
+                    return 0;
+                }
+
+                if (String.Equals(textValue, "infinite", StringComparison.OrdinalIgnoreCase)) {
+                    return 0;
+                }
+            }
+
+            return base.ConvertFrom(context, culture, value);
+        }
+
+
+        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType) {
+            if (destinationType == typeof(string)) {
+                return true;
+            }
+            else {
+                return base.CanConvertTo(context, destinationType);
+            }
+        }
+
+
+        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType) {
+            if ((value != null) && (destinationType == typeof(string)) && ((int)value == 0)) {
+                return "Infinite";
+            }
+            else {
+                return base.ConvertTo(context, culture, value, destinationType);
+            }
+        }
+
+
+        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context) {
+            if (_values == null) {
+                object[] values = new object[] { 0 };
+
+                _values = new StandardValuesCollection(values);
+            }
+            return _values;
+        }
+
+
+        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context) {
+            return false;
+        }
+
+
+        public override bool GetStandardValuesSupported(ITypeDescriptorContext context) {
+            return true;
+        }
+    }
+}
+