Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,128 @@
+//------------------------------------------------------------------------------
+// <copyright file="ListSourceHelper.cs" company="Microsoft">
+//     Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+//------------------------------------------------------------------------------
+
+namespace System.Web.UI {
+
+    using System.Collections;
+    using System.ComponentModel;
+
+    public static class ListSourceHelper {
+
+        public static bool ContainsListCollection(IDataSource dataSource) {
+            ICollection viewNames = dataSource.GetViewNames();
+            if (viewNames != null && viewNames.Count > 0) {
+                return true;
+            }
+            return false;
+        }
+
+
+        public static IList GetList(IDataSource dataSource) {
+            ICollection viewNames = dataSource.GetViewNames();
+            
+            if (viewNames != null && viewNames.Count > 0) {
+                return new ListSourceList(dataSource);
+            }
+            return null;
+        }
+
+        internal sealed class ListSourceList : CollectionBase, ITypedList {
+            IDataSource _dataSource;
+    
+            public ListSourceList(IDataSource dataSource) {
+                _dataSource = dataSource;
+                ((IList)this).Add(new ListSourceRow(_dataSource));
+            }
+
+            #region ITypedList implementation
+            string ITypedList.GetListName(PropertyDescriptor[] listAccessors) {
+                return String.Empty;
+            }
+    
+            PropertyDescriptorCollection ITypedList.GetItemProperties(PropertyDescriptor[] listAccessors) {
+                if (_dataSource != null) {
+                    ICollection viewNames = _dataSource.GetViewNames();
+                    if (viewNames != null && viewNames.Count > 0) {
+                        string[] viewNamesArray = new string[viewNames.Count];
+                        viewNames.CopyTo(viewNamesArray, 0);
+                        PropertyDescriptor[] props = new PropertyDescriptor[viewNames.Count];
+                        for (int i = 0; i < viewNamesArray.Length; i++) {
+                            props[i] = new ListSourcePropertyDescriptor(viewNamesArray[i]);
+                        }
+                        return new PropertyDescriptorCollection(props);
+                    }                    
+                }
+                return new PropertyDescriptorCollection(null);
+            }
+            #endregion ITypedList implementations
+        }
+
+        internal class ListSourceRow {
+            IDataSource _dataSource;
+
+            public ListSourceRow(IDataSource dataSource) {
+                _dataSource = dataSource;
+            }
+
+            public IDataSource DataSource {
+                get {
+                    return _dataSource;
+                }
+            }
+        }
+
+        internal class ListSourcePropertyDescriptor : PropertyDescriptor {
+            string _name;
+
+            public ListSourcePropertyDescriptor(string name) : base(name, null) {
+                _name = name;
+            }
+
+            public override Type ComponentType {
+                get {
+                    return typeof(ListSourceRow);
+                }
+            }
+
+            public override bool IsReadOnly {
+                get {
+                    return true;
+                }
+            }
+
+            public override Type PropertyType {
+                get {
+                    return typeof(IEnumerable);
+                }
+            }
+
+            public override bool CanResetValue(object value) {
+                return false;
+            }
+
+            public override object GetValue(object source) {
+                if (source is ListSourceRow) {
+                    ListSourceRow row = (ListSourceRow)source;
+                    IDataSource dataSource = row.DataSource;
+                    return dataSource.GetView(_name).ExecuteSelect(DataSourceSelectArguments.Empty);
+                }
+                return null;
+            }
+
+            public override void ResetValue(object component) {
+                throw new NotSupportedException();
+            }
+
+            public override void SetValue(object component, object value) {
+                throw new NotSupportedException();
+            }
+
+            public override bool ShouldSerializeValue(object component) {
+                return false;
+            }
+        }
+    }
+}