1 files changed, 244 insertions, 0 deletions
diff --git a/Xamarin.Forms.Controls/GalleryPages/GroupedListContactsGallery.cs b/Xamarin.Forms.Controls/GalleryPages/GroupedListContactsGallery.cs
new file mode 100644
index 00000000..1058b692
--- /dev/null
+++ b/Xamarin.Forms.Controls/GalleryPages/GroupedListContactsGallery.cs
@@ -0,0 +1,244 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.Linq;
+using System.Text;
+
+namespace Xamarin.Forms.Controls
+{
+	[Preserve (AllMembers = true)]
+	public class GroupedListContactsGallery
+		: ContentPage
+	{
+		internal class Contact
+		{
+			public string FirstName
+			{
+				get;
+				set;
+			}
+
+			public string LastName
+			{
+				get;
+				set;
+			}
+
+			public string FullName
+			{
+				get { return FirstName + " " + LastName; }
+			}
+
+			public string Title
+			{
+				get;
+				set;
+			}
+		}
+
+		readonly ListView _list = new ListView {
+			ItemTemplate = new DataTemplate (() => {
+				Label name = new Label();
+				name.SetBinding (Label.TextProperty, "FullName");
+
+				Label title = new Label { Font = Font.SystemFontOfSize (NamedSize.Micro) };
+				title.SetBinding (Label.TextProperty, "Title");
+
+				return new ViewCell { View = new StackLayout  {
+					Children = {
+						name,
+						title
+					}
+				} };
+			}),
+
+			GroupDisplayBinding = new Binding ("Key"),
+			GroupShortNameBinding = new Binding ("Key"),
+			IsGroupingEnabled = true
+		};
+
+		readonly List<Contact> _contacts = new List<Contact> {
+			new Contact { FirstName = "Jason", LastName = "Smith", Title = "Software Engineer" },
+			new Contact { FirstName = "Eric", LastName = "Maupin", Title = "Software Engineer" },
+			new Contact { FirstName = "Seth", LastName = "Rosetter", Title = "Software Engineer"  },
+			new Contact { FirstName = "Stephane", LastName = "Delcroix", Title = "Software Engineer" }
+		};
+
+		readonly Random _rand = new Random (42);
+
+		[Preserve (AllMembers = true)]
+		internal class Group
+			: ObservableCollection<Contact>
+		{
+			public Group (string key)
+			{
+				Key = key;
+			}
+
+			public string Key
+			{
+				get;
+				private set;
+			}
+		}
+
+		bool _sortedByFirst = true;
+		ObservableCollection<Group> _sortedContacts;
+
+		public GroupedListContactsGallery()
+		{
+			var addRandom = new Button { Text = "Random" };
+			addRandom.Clicked += (sender, args) => {
+				Contact contact = GetRandomContact();
+				_contacts.Add (contact);
+
+				AddContact (_sortedContacts, contact);
+			};
+
+			var addRandomToExisting = new Button { Text = "Random Group" };
+			addRandomToExisting.Clicked += (sender, args) => {
+				Contact contact;
+				do {
+					contact = GetRandomContact();
+				} while (!_sortedContacts.Any (g => GetSortChar (g.First()) == GetSortChar (contact)));
+
+				_contacts.Add (contact);
+				AddContact (_sortedContacts, contact);
+			};
+
+			var groupByFirst = new Button { Text = "First" };
+			groupByFirst.Clicked += (sender, args) => {
+				_sortedByFirst = true;
+
+				SetupContacts();
+				_list.ItemsSource = _sortedContacts;
+			};
+
+			var groupByLast = new Button { Text = "Last" };
+			groupByLast.Clicked += (sender, args) => {
+				_sortedByFirst = false;
+
+				SetupContacts();
+				_list.ItemsSource = _sortedContacts;
+			};
+
+			Content = new StackLayout {
+				Orientation = StackOrientation.Vertical,
+				Children = {
+					new StackLayout {
+						Orientation = StackOrientation.Vertical,
+						Children = {
+							new StackLayout {
+								Orientation = StackOrientation.Horizontal,
+								Children = {
+									new Label { Text = "Sort: " },
+									groupByFirst,
+									groupByLast
+								}
+							},
+
+							new StackLayout {
+								Orientation = StackOrientation.Horizontal,
+								Children = {
+									addRandom,
+									addRandomToExisting,
+								}
+							}
+						},
+					},
+					
+
+					_list
+				}
+			};
+
+			SetupContacts();
+			_list.ItemsSource = _sortedContacts;
+		}
+
+		const string Chars = "abcdefghijklmnopqrstuvwxyz";
+
+		void SetupContacts()
+		{
+			var coll = new ObservableCollection<Group>();
+			foreach (var contact in _contacts)
+				AddContact (coll, contact);
+
+			_sortedContacts = coll;
+		}
+
+		void AddContact (ObservableCollection<Group> contactGroups, Contact contact)
+		{
+			char sortChar = GetSortChar (contact);
+
+			var collection = contactGroups.FirstOrDefault (col => {
+				var c = col.First();
+				return (GetSortChar (c) == sortChar);
+			});
+
+			if (collection == null) {
+				var ocontacts = new Group (GetSortChar (contact).ToString()) { contact };
+				InsertBasedOnSort (contactGroups, ocontacts, c => GetSortChar (c.First()));
+			} else
+				InsertBasedOnSort (collection, contact, c => GetSortString (c)[0]);
+		}
+
+		int IndexOf<T> (IEnumerable<T> elements, T element)
+		{
+			int i = 0;
+			foreach (T e in elements) {
+				if (Equals (e, element))
+					return i;
+
+				i++;
+			}
+
+			return -1;
+		}
+
+		void InsertBasedOnSort<T,TSort> (IList<T> items, T item, Func<T, TSort> sortBy)
+		{
+			List<T> newItems = new List<T> (items);
+			newItems.Add (item);
+			int index = IndexOf (newItems.OrderBy (sortBy), item);
+			items.Insert (index, item);
+		}
+
+		char GetSortChar (Contact contact)
+		{
+			return GetSortString (contact)[0];
+		}
+
+		string GetSortString (Contact contact)
+		{
+			return (_sortedByFirst) ? contact.FirstName : contact.LastName;
+		}
+
+		Contact GetRandomContact()
+		{
+			Contact contact = new Contact();
+
+			int firstLen = _rand.Next (3, 7);
+			
+			var builder = new StringBuilder (firstLen);
+			for (int i = 0; i < firstLen; i++) {
+				char c = Chars[_rand.Next (0, Chars.Length)];
+				builder.Append ((i != 0) ? c : char.ToUpper (c));
+			}
+			
+			contact.FirstName = builder.ToString();
+
+			int lastLen = _rand.Next (3, 7);
+			builder.Clear();
+			for (int i = 0; i < lastLen; i++) {
+				char c = Chars[_rand.Next (0, Chars.Length)];
+				builder.Append ((i != 0) ? c : char.ToUpper (c));
+			}
+
+			contact.LastName = builder.ToString();
+			contact.Title = "Software Engineer";
+
+			return contact;
+		}
+	}
+}