/V1/trunk/Source/StockTraderRI/StockTraderRI.Modules.WatchList/WatchList/WatchListPresentationModel.cs

//===============================================================================

// Microsoft patterns & practices

// Composite Application Guidance for Windows Presentation Foundation

//===============================================================================

// Copyright (c) Microsoft Corporation.  All rights reserved.

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT

// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

// FITNESS FOR A PARTICULAR PURPOSE.

//===============================================================================

// The example companies, organizations, products, domain names,

// e-mail addresses, logos, people, places, and events depicted

// herein are fictitious.  No association with any real company,

// organization, product, domain name, email address, logo, person,

// places, or events is intended or should be inferred.

//===============================================================================



using System;

using System.Collections.Generic;

using System.Collections.ObjectModel;

using System.ComponentModel;

using System.Windows.Input;

using Microsoft.Practices.Composite.Events;

using Microsoft.Practices.Composite.Wpf.Commands;

using Microsoft.Practices.Composite.Wpf.Events;

using StockTraderRI.Infrastructure;

using StockTraderRI.Infrastructure.Interfaces;

using StockTraderRI.Modules.Watch.Properties;

using StockTraderRI.Modules.Watch.Services;



namespace StockTraderRI.Modules.Watch.WatchList

{

    public class WatchListPresentationModel : IWatchListPresentationModel, INotifyPropertyChanged, IHeaderInfoProvider<string>

    {

        private ObservableCollection<WatchItem> _watchListItems;



        public WatchListPresentationModel(IWatchListView view, IWatchListService watchListService, IMarketFeedService marketFeedService, IEventAggregator eventAggregator)

        {

            View = view;

            this.HeaderInfo = Resources.WatchListTitle;

            this.WatchListItems = new ObservableCollection<WatchItem>();

            View.Model = this;



            this.marketFeedService = marketFeedService;



            this.watchList = watchListService.RetrieveWatchList();

            watchList.CollectionChanged += delegate { PopulateWatchItemsList(watchList); };

            PopulateWatchItemsList(watchList);



            eventAggregator.GetEvent<MarketPricesUpdatedEvent>().Subscribe(MarketPricesUpdated, ThreadOption.UIThread);

            RemoveWatchCommand = new DelegateCommand<string>(RemoveWatch);

        }





        public ObservableCollection<WatchItem> WatchListItems

        {

            get { return _watchListItems; }

            set

            {

                if (_watchListItems != value)

                {

                    _watchListItems = value;

                    PropertyChanged(this, new PropertyChangedEventArgs("WatchListItems"));

                }

            }

        }



        public string HeaderInfo { get; set; }



        #region INotifyPropertyChanged Members



        public event PropertyChangedEventHandler PropertyChanged = delegate { };



        #endregion



        private void MarketPricesUpdated(IDictionary<string, decimal> updatedPriceList)

        {

            foreach (WatchItem watchItem in this.WatchListItems)

            {

                if (updatedPriceList.ContainsKey(watchItem.TickerSymbol))

                    watchItem.CurrentPrice = updatedPriceList[watchItem.TickerSymbol];

            }

        }



        private void RemoveWatch(string tickerSymbol)

        {

            watchList.Remove(tickerSymbol);

        }



        private void PopulateWatchItemsList(ObservableCollection<string> watchItemsList)

        {

            this.WatchListItems.Clear();

            foreach (string tickerSymbol in watchItemsList)

            {

                decimal? currentPrice;

                try

                {

                    currentPrice = marketFeedService.GetPrice(tickerSymbol);

                }

                catch (ArgumentException)

                {

                    currentPrice = null;

                }

                this.WatchListItems.Add(new WatchItem(tickerSymbol, currentPrice));

            }

        }



        public IWatchListView View { get; private set; }

        public ICommand RemoveWatchCommand { get; private set; }

        private readonly IMarketFeedService marketFeedService;

        private readonly ObservableCollection<string> watchList;

    }

}