MVVM (Part 2) - Commanding


#region using

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Windows;
using System.Windows.Controls;
using HomeGrownMVVM.Helpers;
using HomeGrownMVVM.Model;
using VvmScaffolding;

#endregion using

namespace HomeGrownMVVM.ViewModel
{
	public class ClassicComposerTreeViewModel : BaseViewModel
	{
		#region ObservableCollection<MyTreeNode> DataToPresent

		private ObservableCollection<MyTreeNode> dataToPresent = null;
		public ObservableCollection<MyTreeNode> DataToPresent
		{
			get
			{
				return dataToPresent;
			}
			set
			{
				dataToPresent = value;
				OnPropertyChanged("DataToPresent");
			}
		}

		#endregion ObservableCollection<MyTreeNode> DataToPresent

		#region LoadData

		public override void LoadData()
		{
			base.LoadData();
			if (DataToPresent != null)
			{
				DataToPresent.Clear();
			}
			var fullList = DataProvider.FakeSortedClassicData();
			DataToPresent = ProcessData(fullList);
		}

		#endregion LoadData

		#region ProcessData

		private ObservableCollection<MyTreeNode> ProcessData(List<CompleteClassicData> fullList)
		{
			var shortList = new ObservableCollection<PresntingClassicData>();
			foreach (var completeData in fullList)
			{
				var pd = new PresntingClassicData
				{
					Composer = completeData.ComposerName,
					Composition = completeData.CompositionName,
					Conductor = completeData.Conductor,
					Orquestra = completeData.Orquestra,
					Id = completeData.Id,
					Details = completeData
				};
				shortList.Add(pd);
			}

			var sortHelper = new TreeNodeListGenerator<PresntingClassicData>(GetComoserName, GetCompositionName)
			{
				FirstLevelGroupName = "Composers",
				FirstLevelImagePath = @"../../Images/violin.png",
				SecondLevelGroupName = "Compositions",
				SecondLevelImagePath = @"../../Images/composer.png",
				ThirdLevelImagePath = @"../../Images/MusicalNote.png"
			};

			var treeList = sortHelper.CreateSingleLetterNodes(shortList);

			InfoText = string.Format("Found {0} main nodes at {1}", treeList.Count, DateTime.Now.ToShortTimeString());
			return treeList;
		}

		#endregion ProcessData

		#region delegates for the tree nodes generator

		public virtual string GetComoserName(PresntingClassicData item)
		{
			return item.Composer;
		}

		public virtual string GetCompositionName(PresntingClassicData item)
		{
			return item.Composition;
		}

		#endregion  delegates for the tree nodes generator

		#region LoadedAction

		protected override void LoadedAction(object param)
		{
			var pw = param as ParameterWrapper;
			if (pw != null)
			{
				var tv = pw.Sender as TreeView;
				if (tv != null)
				{
					var tvi = tv.ItemContainerGenerator.ContainerFromItem(tv.Items[0]) as TreeViewItem;
					if (tvi != null)
					{
						tvi.IsExpanded = true;
					}
				}
			}
		}

		#endregion LoadedAction
	}
}