Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

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

@@ -0,0 +1,150 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Web.Util;
+
+namespace System.Web.UI.WebControls {
+    public abstract class AutoFieldsGenerator : IAutoFieldGenerator, IStateManager {
+        private List<AutoGeneratedFieldProperties> _autoGeneratedFieldProperties;
+        private bool _tracking;
+
+        internal bool InDataBinding {
+            get;
+            set;
+        }
+
+        internal object DataItem {
+            get;
+            set;
+        }
+
+        private ICollection CreateAutoGeneratedFieldsFromFieldProperties() {
+            List<AutoGeneratedField> autoFields = new List<AutoGeneratedField>();
+
+            foreach (AutoGeneratedFieldProperties fieldProperties in AutoGeneratedFieldProperties) {
+                autoFields.Add(CreateAutoGeneratedFieldFromFieldProperties(fieldProperties));
+            }
+
+            return autoFields;
+        }
+
+        //internal for unit testing.
+        protected internal List<AutoGeneratedFieldProperties> AutoGeneratedFieldProperties {
+            get {
+                if (_autoGeneratedFieldProperties == null) {
+                    _autoGeneratedFieldProperties = new List<AutoGeneratedFieldProperties>();
+                }
+                return _autoGeneratedFieldProperties;
+            }
+        }
+
+        /// <devdoc>
+        /// Create a single autogenerated field.  This function can be overridden to create a different AutoGeneratedField.
+        /// </devdoc>
+        protected virtual AutoGeneratedField CreateAutoGeneratedFieldFromFieldProperties(AutoGeneratedFieldProperties fieldProperties) {
+            AutoGeneratedField field = new AutoGeneratedField(fieldProperties.DataField);
+            string name = fieldProperties.Name;
+            ((IStateManager)field).TrackViewState();
+
+            field.HeaderText = name;
+            field.SortExpression = name;
+            field.ReadOnly = fieldProperties.IsReadOnly;
+            field.DataType = fieldProperties.Type;
+
+            return field;
+        }
+
+        protected bool IsTrackingViewState {
+            get {
+                return _tracking;
+            }
+        }
+
+        protected virtual void TrackViewState() {
+            _tracking = true;
+            foreach (object fieldProps in AutoGeneratedFieldProperties) {
+                ((IStateManager)fieldProps).TrackViewState();
+            }
+        }
+
+        protected virtual void LoadViewState(object savedState) {
+            if (savedState != null) {
+                object[] autoGenFieldStateArray = (object[])savedState;
+                int fieldCount = autoGenFieldStateArray.Length;
+                AutoGeneratedFieldProperties.Clear();
+
+                for (int i = 0; i < fieldCount; i++) {
+                    AutoGeneratedFieldProperties fieldProps = new AutoGeneratedFieldProperties();
+                    ((IStateManager)fieldProps).TrackViewState();
+                    ((IStateManager)fieldProps).LoadViewState(autoGenFieldStateArray[i]);
+                    AutoGeneratedFieldProperties.Add(fieldProps);
+                }
+            }
+        }
+
+        protected virtual object SaveViewState() {
+            // pack up the auto gen'd field properties
+            int autoGenFieldPropsCount = AutoGeneratedFieldProperties.Count;
+            object[] autoGenFieldState = new object[autoGenFieldPropsCount];
+
+            for (int i = 0; i < autoGenFieldPropsCount; i++) {
+                autoGenFieldState[i] = ((IStateManager)AutoGeneratedFieldProperties[i]).SaveViewState();
+            }
+            return autoGenFieldState;
+        }
+
+        /// <summary>
+        /// Method that creates the AutoGeneratedFields. This would also typically populate the AutoGeneratedFieldProperties collection
+        /// which are tracked by view state.
+        /// </summary>
+        /// <returns></returns>
+        public abstract List<AutoGeneratedField> CreateAutoGeneratedFields(object dataItem, Control control);
+
+        /// <summary>
+        /// A flag to indicate whether Enum fields should be generated by this FieldGenerator.
+        /// If this flag is not set, the FieldGenerator uses <see cref='System.Web.UI.WebControls.Control.RenderingCompatibility'/> of
+        /// <see cref='System.Web.UI.WebControls.Control'/> to determine the default behavior which is 
+        /// true when RenderingCompatibility is greater than or equal to 4.5 and false in older versions.
+        /// </summary>
+        public bool? AutoGenerateEnumFields {
+            get;
+            set;
+        }
+
+        #region Implementation of IAutoFieldGenerator
+
+        public virtual ICollection GenerateFields(Control control) {
+            if (InDataBinding) {
+                //Reset this collection as this would be populated by CreateAutoGenerateFields.
+                _autoGeneratedFieldProperties = null;
+                return CreateAutoGeneratedFields(DataItem, control);
+            }
+            else {
+                return CreateAutoGeneratedFieldsFromFieldProperties();
+            }
+        }
+
+        #endregion
+
+        #region Implementation of IStateManager
+
+        bool IStateManager.IsTrackingViewState {
+            get {
+                return IsTrackingViewState;
+            }
+        }
+
+        void IStateManager.LoadViewState(object savedState) {
+            LoadViewState(savedState);
+        }
+
+        object IStateManager.SaveViewState() {
+            return SaveViewState();
+        }
+
+        void IStateManager.TrackViewState() {
+            TrackViewState();
+        }
+
+        #endregion
+    }
+}