Adds comments.

Change-Id: If007d716aa2c6befdf3325313b5de47a2c0da63c
Signed-off-by: Hyerim Kim <rimi.kim@samsung.com>

5 files changed, 93 insertions, 3 deletions

diff --git a/VideoPlayerLite/VideoPlayerLite.Android/Port/MediaContentPort.cs b/VideoPlayerLite/VideoPlayerLite.Android/Port/MediaContentPort.cs
index 8b51c8a..bcc19fb 100755
--- a/VideoPlayerLite/VideoPlayerLite.Android/Port/MediaContentPort.cs
+++ b/VideoPlayerLite/VideoPlayerLite.Android/Port/MediaContentPort.cs
@@ -30,6 +30,11 @@ using VideoPlayerLite.Models;
 
 namespace VideoPlayerLite.Android.Port
 {
+    /// <summary>
+    /// A class for implementing the IMediaContentAPIs interface.
+    /// Gets the video items from the device and creates the thumbnail of the item if needed.
+    /// Returns the list of MediaItem that is created by the redefinition of the video item.
+    /// </summary>
     public class MediaContentPort : IMediaContentAPIs
     {
         private string[] videoProjection =
@@ -39,6 +44,11 @@ namespace VideoPlayerLite.Android.Port
             MediaStore.Video.VideoColumns.Duration
         };
 
+        /// <summary>
+        /// Gets all the video items stored in the device.
+        /// Creates the list of MediaItem that is redefined from the video items.
+        /// </summary>
+        /// <returns>A list of the MediaItem.</returns>
         public async Task<IEnumerable<MediaItem>> GetAllVideoItemListAsync()
         {
             var itemList = new List<MediaItem>();
@@ -72,6 +82,12 @@ namespace VideoPlayerLite.Android.Port
             return itemList;
         }
 
+        /// <summary>
+        /// Gets the path of the specific media content.
+        /// </summary>
+        /// <param name="uri">The URI to be used to query.</param>
+        /// <param name="documentId">The id of a specific media to get the path.</param>
+        /// <returns></returns>
         private string GetMediaContentPath(global::Android.Net.Uri uri, string documentId)
         {
             var path = String.Empty;
@@ -86,6 +102,11 @@ namespace VideoPlayerLite.Android.Port
             return path;
         }
 
+        /// <summary>
+        /// Creates the thumbnail of video item and stores it to a file.
+        /// </summary>
+        /// <param name="path">A path of the video file to create the thumbnail.</param>
+        /// <returns>A path of the created thumbnail.</returns>
         private async Task<string> SaveThumbnailToFileAsync(string path)
         {
             return await Task.Run(() =>
@@ -107,6 +128,13 @@ namespace VideoPlayerLite.Android.Port
             });
         }
 
+        /// <summary>
+        /// Stores the created thumbnail to a file.
+        /// The path to store refers to the path of the video item.
+        /// </summary>
+        /// <param name="path">The path of the video item to create the thumbnail.</param>
+        /// <param name="bitmap">The created thumbnail.</param>
+        /// <returns>The path of the stored file.</returns>
         private string SaveToFile(string path, Bitmap bitmap)
         {
             var thumbnailPath = System.IO.Path.ChangeExtension(path, ".jpeg");
diff --git a/VideoPlayerLite/VideoPlayerLite/Models/DurationConverter.cs b/VideoPlayerLite/VideoPlayerLite/Models/DurationConverter.cs
index 4a4335e..8c4a54f 100755
--- a/VideoPlayerLite/VideoPlayerLite/Models/DurationConverter.cs
+++ b/VideoPlayerLite/VideoPlayerLite/Models/DurationConverter.cs
@@ -20,13 +20,35 @@ using System;
 
 namespace VideoPlayerLite.Models
 {
+    /// <summary>
+    /// A custom converter made by inherited the IValueConverter interface.
+    /// </summary>
     public class DurationConverter : IValueConverter
     {
+        /// <summary>
+        /// Converts a value from the binding source to the binding target.
+        /// In this project, converting the current position of the video being played and the duration to a specific string format,
+        /// and the converted value is provided to the binding target.
+        /// </summary>
+        /// <param name="value">The value produced by the binding source.</param>
+        /// <param name="targetType">The type of the binding target property.</param>
+        /// <param name="parameter">The converter parameter to be used.</param>
+        /// <param name="culture">The culture to be used in the converter.</param>
+        /// <returns>A converted value.</returns>
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {            
             return TimeSpan.FromMilliseconds((int)value).ToString("mm':'ss");
         }
 
+        /// <summary>
+        /// Converts a value from the binding target to the binding source.
+        /// In this project, this method is not used.
+        /// </summary>
+        /// <param name="value">The value that is producted by the binding target.</param>
+        /// <param name="targetType">The type to convert to.</param>
+        /// <param name="parameter">The converter parameter to be used.</param>
+        /// <param name="culture">The culture to be used in the converter.</param>
+        /// <returns>A converted value.</returns>
         public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
         {
             throw new NotImplementedException();
diff --git a/VideoPlayerLite/VideoPlayerLite/ViewModels/ItemViewModel.cs b/VideoPlayerLite/VideoPlayerLite/ViewModels/ItemViewModel.cs
index b12048d..6e6fcd4 100755
--- a/VideoPlayerLite/VideoPlayerLite/ViewModels/ItemViewModel.cs
+++ b/VideoPlayerLite/VideoPlayerLite/ViewModels/ItemViewModel.cs
@@ -19,6 +19,9 @@ using Xamarin.Forms;
 
 namespace VideoPlayerLite.ViewModels
 {
+    /// <summary>
+    /// A viewmodel for item view that is displayed in the library page
+    /// </summary>
     class ItemViewModel : ViewModelBase
     {
 
@@ -34,11 +37,11 @@ namespace VideoPlayerLite.ViewModels
             }
         }
 
-
-        // When creating a bindable property, the property must have getter as public.
-        // To make a public getter, it has to be defined explicitly.
         private Command setNewVideoCommand;
 
+        /// <summary>
+        /// A property for command to be executed when the item in the library page is selected.
+        /// </summary>
         public Command SetNewVideoCommand
         {
             get => setNewVideoCommand;
@@ -49,6 +52,12 @@ namespace VideoPlayerLite.ViewModels
             }
         }
 
+        /// <summary>
+        /// A constructor of the ItemViewModel class
+        /// Stores the parameter to the VideoItem in this class.
+        /// Implements the SetNewVideoCommand.
+        /// </summary>
+        /// <param name="item">The MediaItem that is passed when the ItemView is created.</param>
         public ItemViewModel(MediaItem item)
         {
             VideoItem = item;
diff --git a/VideoPlayerLite/VideoPlayerLite/ViewModels/ViewModelBase.cs b/VideoPlayerLite/VideoPlayerLite/ViewModels/ViewModelBase.cs
index a6e7b1e..a868870 100755
--- a/VideoPlayerLite/VideoPlayerLite/ViewModels/ViewModelBase.cs
+++ b/VideoPlayerLite/VideoPlayerLite/ViewModels/ViewModelBase.cs
@@ -19,10 +19,22 @@ using System.Runtime.CompilerServices;
 
 namespace VideoPlayerLite.ViewModels
 {
+    /// <summary>
+    /// This class is the base class for the other viewmodels.
+    /// Other viewmodels in this project inherit this class
+    /// and can use OnPropertyChanged method to invoke PropertyChanged event.
+    /// </summary>
     public class ViewModelBase : INotifyPropertyChanged
     {
+        /// <summary>
+        /// An event that is triggered when property is changed
+        /// </summary>
         public event PropertyChangedEventHandler PropertyChanged;
 
+        /// <summary>
+        /// A method for invoking PropertyChanged event
+        /// </summary>
+        /// <param name="propertyName">The name of property that is changed. The default value is null.</param>
         protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
         {
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
diff --git a/VideoPlayerLite/VideoPlayerLite/Views/PlayerButton.xaml.cs b/VideoPlayerLite/VideoPlayerLite/Views/PlayerButton.xaml.cs
index 60af409..b7d09e7 100755
--- a/VideoPlayerLite/VideoPlayerLite/Views/PlayerButton.xaml.cs
+++ b/VideoPlayerLite/VideoPlayerLite/Views/PlayerButton.xaml.cs
@@ -19,10 +19,19 @@ using Xamarin.Forms;
 
 namespace VideoPlayerLite.Views
 {
+    /// <summary>
+    /// A custom layout for displaying the play/pause, previous and next buttons in the player page.
+    /// </summary>
     public partial class PlayerButton : RelativeLayout
     {
+        /// <summary>
+        /// An event to be invoked to the PlayerPage when the button is clicked.
+        /// </summary>
         public event EventHandler Clicked;
 
+        /// <summary>
+        /// A string property sets to or gets from the source of Icon image.
+        /// </summary>
         public string ButtonImage
         {
             get => Icon.Source.ToString();
@@ -33,12 +42,19 @@ namespace VideoPlayerLite.Views
             }
         }
 
+        /// <summary>
+        /// A string property sets to or gets from the CommandParameter defined in the PlayerButton.xaml.
+        /// </summary>
         public string ButtonName
         {
             get => FocusButton.CommandParameter.ToString();
             set => FocusButton.CommandParameter = value;
         }
 
+        /// <summary>
+        /// A constructor of the PlayerButton class
+        /// Implements the click event of button in order to invoke the event to the PlayerPage.
+        /// </summary>
         public PlayerButton()
         {
             InitializeComponent();
@@ -46,6 +62,9 @@ namespace VideoPlayerLite.Views
             FocusButton.Clicked += (s, e) => Clicked?.Invoke(this, EventArgs.Empty);
         }
 
+        /// <summary>
+        /// Focuses to the button object of PlayerButton.
+        /// </summary>
         public void SetFocus()
         {
             FocusButton.Focus();