Basic AdjutantOS android add-on that browses and plays videos on a selected computer.

MainActivity.cs

using System;
using Android.App;
using Android.Content;
using Android.Views;
using Android.Widget;
using Android.OS;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.Linq;

using FragLabs.AdjutantOS.API;
using FragLabs.AdjutantOS.API.Addons;
using FragLabs.AdjutantOS.API.Devices;
using FragLabs.AdjutantOS.API.Log;

namespace FragLabs.AdjutantOS.Apps.Video
{
	[Activity (Label = "AdjutantOS Video", MainLauncher = true)]
	public class MainActivity : ListActivity
	{
		private List<string> _items = new List<string>();
		private ArrayAdapter<string> _adapter;
		private Dtos.BrowseItem[] _browseItems;
		private List<string> _browsePath = new List<string>();

		protected async override void OnCreate (Bundle bundle)
		{
			base.OnCreate (bundle);

			_adapter = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleListItem1, _items);
			ListAdapter = _adapter;

			AddonClient.Server.Connected += async (sender, e) => await DirectoryListing();
			AddonClient.Server.Disconnected += async (sender, e) => await DirectoryListing();
			await DirectoryListing();
		}

		protected override async void OnListItemClick (ListView l, View v, int position, long id)
		{
			base.OnListItemClick (l, v, position, id);
			var item = _browseItems[position];
			if (item.Type == Dtos.BrowseItemType.Directory || item.Type == Dtos.BrowseItemType.Mount)
			{
				_browsePath.Add(item.Path);
				await DirectoryListing();
			}
			else if (item.Type == Dtos.BrowseItemType.File)
			{
				var intent = new Intent(this, typeof(ChooseDevice));
				intent.PutExtra("filename", item.Path);
				StartActivityForResult(intent, 1);
			}
		}

		protected async override void OnActivityResult (int requestCode, Result resultCode, Intent data)
		{
			base.OnActivityResult (requestCode, resultCode, data);
			if (requestCode == 1)
			{
				if (resultCode == Result.Ok)
				{
					var filename = data.GetStringExtra("filename") ?? "";
					var deviceIdStr = data.GetStringExtra("computerId") ?? "";
					var deviceId = Guid.Parse(deviceIdStr);
					var computer = DeviceRepository.GetSingle<Computer>(deviceId);
					Logger.Write(LogLevel.Debug, "Starting playback of {0} on {1}", filename, deviceId);
					try
					{
						var response = await ServiceInvoker.Call<Dtos.PlayResponse>(computer, new Dtos.Play {
							Mount = _browsePath[0],
							Directory = String.Join("/",_browsePath.Skip(1)),
							Filename = filename
						});
						if (!response.IsPlaying)
						{
							ShowToast("Failed to play video");
						}
					} catch(Exception ex) {
						Logger.Write(LogLevel.Warning, "Failed to play video: {0}", ex);
						ShowToast("An error occured while trying to play video");
					}
				}
			}
		}

		public override async void OnBackPressed ()
		{
			if (_browsePath.Count == 0)
			{
				base.OnBackPressed();
				return;
			}
			_browsePath.RemoveAt(_browsePath.Count - 1);
			await DirectoryListing();
		}

		private async Task DirectoryListing()
		{
			if (!AddonClient.Server.IsConnected)
			{
				_items.Clear();
				_items.Add("Not connected");
				SyncUI();
				return;
			}
			try
			{
				var request = new Dtos.Browse{Mount = null, Directory = ""};
				if (_browsePath.Count > 0)
				{
					request.Mount = _browsePath[0];
					if (_browsePath.Count > 1)
					{
						request.Directory = String.Join("/", _browsePath.Skip(1));
					}
				}
				var browseResp = await ServiceInvoker.Call<Dtos.BrowseResponse>(DeviceRepository.Server,
					request);
				_browseItems = browseResp.Items.OrderBy(t => t.Type).ThenBy(str => str.Name, new NaturalSortComparer<string>()).ToArray();
				_items.Clear();
				foreach(var item in _browseItems)
				{
					_items.Add(item.Name);
				}
				SyncUI();
			}
			catch(Exception ex)
			{
				ShowToast("An error occured while listing directory");
				Logger.Write(LogLevel.Warning, "Error while listing directory: {0}", ex);
			}
		}

		private void SyncUI()
		{
			RunOnUiThread(delegate {
				_adapter.Clear();
				foreach(var item in _items)
					_adapter.Add(item);
			});
		}

		private void ShowToast(string text)
		{
			RunOnUiThread(delegate {
				Toast.MakeText(this, text, ToastLength.Short).Show();
			});
		}
	}
}