ContactOverViewDataSource

using System;
using System.Drawing;
using System.Collections.Generic;
using MonoTouch.Foundation;
using MonoTouch.UIKit;
using MonoTouch.ObjCRuntime;
using System.Linq;

namespace Planning
{
    public class ContactOverviewDataSource : UITableViewSource
    {
        private List<Contact> contacts;
        private Dictionary<string, List<Contact>> indexedTableItems;
        private string[] keys;

        public ContactOverviewDataSource (List<Contact> contacts)
        {
            this.contacts = contacts;

            char[] letters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToArray ();
            keys = new string[letters.Length];

            for (int i = 0; i < letters.Length; i++)
            {
                keys [i] = letters [i].ToString ();
            }

            indexedTableItems = new Dictionary<string, List<Contact>> ();

            foreach (var key in keys)
            {
                List<Contact> temp = new List<Contact> ();

                foreach (var contact in contacts)
                {
                    if (contact.LastName.ToLower()[0].ToString() == key.ToLower ())
                    {
                        temp.Add (contact);
                    }
                }

                indexedTableItems.Add (key, temp);
            }
        }

        public override float GetHeightForRow (UITableView tableView, NSIndexPath indexPath)
        {
            if (AppDelegate.IsPhone)
            {
                return 35;
            }

            else
            {
                return 55;
            }
        }

        public override void RowSelected (UITableView tableView, NSIndexPath indexPath)
        {
            if (OnRowSelected != null)
            {
                OnRowSelected (this, new RowSelectedEventArgs (tableView, indexPath));
            }
        }

        public override int NumberOfSections (UITableView tableView)
        {
            int length = keys.Length;
            int xSections = 0;

            for (int i = 0; i < length; i++)
            {
                if (RowsInSection(tableView, i) > 0)
                {
                    xSections++;
                }
            }

            return xSections;
        }

        public override int RowsInSection (UITableView tableview, int section)
        {
            return indexedTableItems [keys [section]].Count;
        }

        public override string[] SectionIndexTitles (UITableView tableView)
        {
            return keys;
        }

        public override string TitleForHeader (UITableView tableView, int section)
        {
            if (RowsInSection (tableView, section) > 0)
            {
                return keys [section];
            }

            else
            {
                return null;
            }
        }

        public override UIView GetViewForHeader (UITableView tableView, int section)
        {
            if (RowsInSection (tableView, section) > 0)
            {
                var view = new UIView (new RectangleF (0, 0, tableView.Bounds.Width, 37));

                var label = new UILabel (new RectangleF (25, 5, 120, 50))
                {
                    Text = TitleForHeader (tableView, section),
                    TextAlignment = UITextAlignment.Left,
                    TextColor = UIColor.White,
                    Font = UIFont.BoldSystemFontOfSize (UIFont.LabelFontSize)
                };

                label.SizeToFit ();
                view.BackgroundColor = UIColor.DarkGray;
                view.AddSubview (label);

                return view;
            }

            else
            {
                return null;
            }
        }

        public override float GetHeightForHeader (UITableView tableView, int section)
        {
            if (RowsInSection (tableView, section) > 0)
            {
                return 30;
            }

            else
            {
                return 0;
            }
        }

        public class RowSelectedEventArgs : EventArgs
        {
            public UITableView tableView { get; set; }

            public NSIndexPath indexPath { get; set; }

            public RowSelectedEventArgs (UITableView tableView, NSIndexPath indexPath) : base ()
            {
                this.tableView = tableView;
                this.indexPath = indexPath;
            }
        }

        public event EventHandler<RowSelectedEventArgs> OnRowSelected;

        public override UITableViewCell GetCell (UITableView tableView, NSIndexPath indexPath)
        {
            Contact contact = null;

            List<Contact> temp = new List<Contact> ();

            foreach (var c in contacts)
            {
                if (c.LastName.ToLower()[0].ToString() == keys [indexPath.Section].ToLower())
                {
                    temp.Add (c);
                }
            }

            contact = temp [indexPath.Row];

            UITableViewCell cell = new UITableViewCell (new RectangleF (0, 0, AppDelegate.ScreenWidth, 90));
            UIView bg = new UIView (cell.Bounds);
            bg.BackgroundColor = AppDelegate.Theme;

            cell.SelectionStyle = UITableViewCellSelectionStyle.Default;
            cell.SelectedBackgroundView = bg;

            string info = "(" + contact.ContactID + ") " + contact.ContactName;

            UILabel lblInfo = new UILabel (new RectangleF (5, 7, AppDelegate.ScreenWidth - cell.Frame.X - 5, cell.Frame.Height));
            lblInfo.TextAlignment = UITextAlignment.Left;
            lblInfo.Text = info;
            lblInfo.Font = AppDelegate.TextFont;
            lblInfo.Lines = 0;
            lblInfo.LineBreakMode = UILineBreakMode.WordWrap;
            lblInfo.SizeToFit ();

            cell.AddSubview (lblInfo);
            return cell;
        }
    }
}