First pass at songs view

Using data grid for songs view. Added FileSystemUtil for async folder traversal

Aurora/Frontend/Models/Song.cs

@@ -0,0 +1,41 @@
+using System;
+
+namespace Aurora.Frontend.Views.Songs
+{
+    public class Song
+    {
+        public Song()
+        {
+        }
+
+        /// <summary>
+        /// The title of the song.
+        /// </summary>
+        /// <value></value>
+        public string Title { get; set; }
+
+        /// <summary>
+        /// The artist of the song.
+        /// </summary>
+        /// <value></value>
+        public string Artist { get; set; }
+
+        /// <summary>
+        /// The album from which the song belongs.
+        /// </summary>
+        /// <value></value>
+        public string Album { get; set; }
+
+        /// <summary>
+        /// The duration of the song.
+        /// </summary>
+        /// <value></value>
+        public string Duration { get; set; }
+
+        /// <summary>
+        /// Extra data associated with a song.
+        /// </summary>
+        /// <value></value>
+        public object Metadata { get; set; }
+    }
+}

Aurora/Frontend/Utils/FileSystemUtils.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Aurora.Frontend.Utils
+{
+    public class FileSystemUtils
+    {
+
+        public FileSystemUtils()
+        {
+        }
+
+
+        /// <summary>
+        /// Asynchronousely recursively traverse a directory path.
+        /// </summary>
+        /// <param name="path">The path to the directory to traverse</param>
+        /// <param name="extensions">Comma separated list of file extensions to accept</param>
+        public static List<FileInfo> TraverseFoldersAsync(string path, string extensions)
+        {
+            string[] extensionList = extensions.Split(',');
+
+            ConcurrentBag<Task> tasks = new ConcurrentBag<Task>();
+            List<FileInfo> outFiles = new List<FileInfo>();
+            DirectoryInfo directoryInfo = new DirectoryInfo(path);
+
+            tasks.Add(Task.Run(() => Traverse(directoryInfo, tasks, outFiles, extensionList)));
+
+            Task waitingTask;
+            while (tasks.TryTake(out waitingTask))
+            {
+                waitingTask.Wait();
+            }
+
+            return outFiles;
+        }
+
+
+
+        /// <summary>
+        /// Recursive method to capture children of a directory.
+        /// </summary>
+        /// <param name="dir">The directory to traverse</param>
+        /// <param name="tasks">The list of currently running tasks</param>
+        private static void Traverse(DirectoryInfo dir, ConcurrentBag<Task> tasks, List<FileInfo> outFiles, string[] extensions)
+        {
+            try
+            {
+                DirectoryInfo[] directoryInfos = dir.GetDirectories();
+                //Enque children
+                foreach (DirectoryInfo childInfo in directoryInfos)
+                {
+                    tasks.Add(Task.Run(() => Traverse(childInfo, tasks, outFiles, extensions)));
+                }
+
+                //Collect files
+                foreach (FileInfo fileInfo in dir.GetFiles())
+                {
+                    if (extensions.Any(e => e == fileInfo.Extension))
+                    {
+                        //Don't know if this lock is necessary
+                        lock (outFiles)
+                        {
+                            outFiles.Add(fileInfo);
+                        }
+                    }
+
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine($"{ex.GetType()} {ex.Message}\n{ex.StackTrace}");
+                ex = ex.InnerException;
+            }
+        }
+
+    }
+}

Aurora/Frontend/Views/Songs/SongsView.xaml

@@ -1,6 +1,38 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="Aurora.Frontend.Views.Songs.SongsView">
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:dg="clr-namespace:Xamarin.Forms.DataGrid;assembly=Xamarin.Forms.DataGrid"
+             x:Class="Aurora.Frontend.Views.Songs.SongsView">
     <ContentPage.Content>
-        <Label Text="Songs" />
+        <dg:DataGrid ItemsSource="{Binding SongsList}" SelectionEnabled="True" SelectedItem="{Binding SelectedSong}"
+               RowHeight="30" HeaderHeight="50" BorderColor="#CCCCCC" HeaderBackground="#E0E6F8">
+            
+            <!-- Header -->
+            <dg:DataGrid.HeaderFontSize>
+                <OnIdiom x:TypeArguments="x:Double">
+                    <OnIdiom.Tablet>15</OnIdiom.Tablet>
+                    <OnIdiom.Phone>13</OnIdiom.Phone>
+                    <OnIdiom.Desktop>20</OnIdiom.Desktop>
+                </OnIdiom>
+            </dg:DataGrid.HeaderFontSize>
+
+            <!-- Columns -->
+            <dg:DataGrid.Columns>
+                <dg:DataGridColumn Title="Title" PropertyName="Title" Width="2*"/>
+                <dg:DataGridColumn Title="Album" PropertyName="Album" Width="0.95*"/>
+                <dg:DataGridColumn Title="Artist" PropertyName="Artist"  Width="1*"/>
+                <dg:DataGridColumn Title="Duration" PropertyName="Duration"/>
+            </dg:DataGrid.Columns>
+
+            <!-- Row Colors -->
+            <dg:DataGrid.RowsBackgroundColorPalette>
+                <dg:PaletteCollection>
+                    <Color>#F2F2F2</Color>
+                    <Color>#FFFFFF</Color>
+                </dg:PaletteCollection>
+            </dg:DataGrid.RowsBackgroundColorPalette>
+
+            
+        </dg:DataGrid>
     </ContentPage.Content>
 </ContentPage>

Aurora/Frontend/Views/Songs/SongsView.xaml.cs

@@ -10,6 +10,7 @@ namespace Aurora.Frontend.Views.Songs
         public SongsView()
         {
             InitializeComponent();
+            BindingContext = new SongsViewModel();
         }
     }
 }

Aurora/Frontend/Views/Songs/SongsViewModel.cs

@@ -1,10 +1,77 @@
 using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+using System.IO;
+using Aurora.Frontend.Utils;
+
 namespace Aurora.Frontend.Views.Songs
 {
-    public class SongsViewModel
+    public class SongsViewModel : BaseViewModel
     {
+        #region Fields
+        private string _pathName = "/Users/brandonwatson/Music/iTunes/iTunes Media/Music";
+        private string _extensions = ".wav,.mp3,.aiff,.flac,.m4a,.m4b,.wma";
+        private ObservableCollection<Song> _songsList;
+        private Song _selectedSong;
+
+        #endregion Fields
+
+        #region Constructor
         public SongsViewModel()
         {
+            _songsList = new ObservableCollection<Song>();
+            Initialize();
         }
+
+        #endregion Constructor
+
+        #region Properties
+        public ObservableCollection<Song> SongsList
+        {
+            get { return _songsList; }
+            set
+            {
+                if (value != _songsList)
+                {
+                    _songsList = value;
+                    OnPropertyChanged("SongList");
+                }
+            }
+        }
+
+        public Song SelectedSong
+        {
+            get { return _selectedSong; }
+            set
+            {
+                if (value != _selectedSong)
+                {
+                    _selectedSong = value;
+                    OnPropertyChanged("SelectedSong");
+                }
+            }
+        }
+
+        #endregion Properties
+
+        #region Methods
+        public void Initialize()
+        {
+            List<FileInfo> musicFiles = FileSystemUtils.TraverseFoldersAsync(_pathName, _extensions);
+
+            foreach (FileInfo file in musicFiles)
+            {
+                TagLib.File tagFile = TagLib.File.Create(file.FullName);
+                _songsList.Add(new Song()
+                {
+                    Title = tagFile.Tag.Title,
+                    Album = tagFile.Tag.Album,
+                    Artist = tagFile.Tag.FirstAlbumArtist
+                });
+            }
+        }
+
+        #endregion Methods
+
     }
 }