fixes the estimate line edition

BookAStar/BookAStar/Views/EnumPicker.cs

@@ -0,0 +1,114 @@
+using BookAStar.Extensions;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xamarin.Forms;
+
+namespace BookAStar.Views
+{
+    /// <summary>
+    ///     A control for picking an element from an enumerated type.
+    /// </summary>
+    public class EnumPicker : Picker
+    {
+        #region Static Fields
+        /// <summary>
+        /// The source used to build values for this picker
+        /// is any enum value from the desired enum type
+        /// </summary>
+        public static BindableProperty EnumSourceProperty =
+            BindableProperty.Create(
+                "EnumSource", typeof(Enum), typeof(EnumPicker),
+                default(Enum), BindingMode.OneWay, propertyChanged: OnEnumSourceChanged);
+
+        public static BindableProperty SelectedItemProperty =
+            BindableProperty.Create("SelectedItem", typeof(Enum), typeof(EnumPicker),
+                default(Enum), BindingMode.TwoWay, null, propertyChanged: OnSelectedItemChanged);
+
+        #endregion
+
+        #region Constructors and Destructors
+
+        public EnumPicker()
+        {
+            this.SelectedIndexChanged += this.OnSelectedIndexChanged;
+        }
+
+        #endregion
+
+        #region Public Properties
+
+        public Enum EnumSource
+        {
+            get
+            {
+                return (Enum)this.GetValue(EnumSourceProperty);
+            }
+            set
+            {
+                this.SetValue(EnumSourceProperty, value);
+            }
+        }
+
+        public Enum SelectedItem
+        {
+            get
+            {
+                return (Enum)this.GetValue(SelectedItemProperty);
+            }
+            set
+            {
+                this.SetValue(SelectedItemProperty, value);
+            }
+        }
+
+        #endregion
+
+        #region Methods
+        private static void OnEnumSourceChanged(BindableObject bindable, object oldValue, object newValue)
+        {
+            var picker = bindable as EnumPicker;
+            if (picker == null)
+            {
+                return;
+            }
+            if (newValue == null)
+            {
+                return;
+            }
+            // Find the values not already contained in the Picker's list of items.
+            var items = EnumExtensions.GetDescriptions(newValue.GetType());
+            var toBeAdded = items.Where(item => !picker.Items.Contains(item));
+            foreach (var item in toBeAdded)
+            {
+                picker.Items.Add(item);
+            }
+        }
+        private static void OnSelectedItemChanged(BindableObject bindable, object oldValue, object newValue)
+        {
+            var picker = bindable as EnumPicker;
+            if (newValue == null || oldValue == newValue || picker == null)
+            {
+                return;
+            }
+            picker.SelectedIndex = picker.Items.IndexOf(((Enum)newValue).GetDescription());
+        }
+        private void OnSelectedIndexChanged(object sender, EventArgs eventArgs)
+        {
+            var picker = sender as EnumPicker;
+            if (null == picker || (this.SelectedIndex < 0 || this.SelectedIndex > this.Items.Count - 1))
+            {
+                return;
+            }
+
+            var type = this.EnumSource.GetType();
+            var values = EnumExtensions.GetDescriptions(type);
+            var items = (from object item in values select item).ToList();
+            picker.SelectedItem = EnumExtensions.GetEnumFromDescription(items[this.SelectedIndex].ToString(), type);
+        }
+
+        #endregion
+    }
+}