aurora-sharp-desktop/Aurora/Design/Views/Party/PartyViewModel.cs

using System;
using System.Collections.ObjectModel;
using Aurora.Executors;
using Aurora.Proto;
using Xamarin.Forms;

namespace Aurora.Design.Views.Party
{
    enum PartyState
    {
        SelectingHost,
        InParty,
        Connecting,
    }

    public class PartyViewModel : BaseViewModel
    {
        private PartyState _state;

        private BaseExecutor _executor;

        private string _hostname;

        private ObservableCollection<PartyMember> _members;


        public PartyViewModel()
        {
            this.JoinCommand = new Command(OnJoinExecute, CanJoinExecute);
            this.HostCommand = new Command(OnHostExecute, CanHostExecute);
            _members = new ObservableCollection<PartyMember>();

            State(PartyState.SelectingHost);
        }
        #region Properties

        public ObservableCollection<PartyMember> Members
        {
            get
            {
                return _members;
            }
            set { SetProperty(ref _members, value); }
        }

        public bool IsSelectingHost
        {
            get { return _state == PartyState.SelectingHost; }
        }

        public bool IsNotSelectingHost
        {
            get { return _state != PartyState.SelectingHost; }
        }

        public Command JoinCommand { get; set; }
        public Command HostCommand { get; set; }

        public string Hostname
        {
            get { return _hostname; }
            set { SetProperty(ref _hostname, value); }
        }

        #endregion Properties


        private void State(PartyState state)
        {
            _state = state;
            OnPropertyChanged("IsSelectingHost");
            OnPropertyChanged("IsNotSelectingHost");
        }

        #region Commands
        private void OnJoinExecute()
        {
            _executor = BaseExecutor.CreateExecutor<ClientExecutor>();
            _executor.Connect(this.Hostname);

            SetUpMembers();

            State(PartyState.Connecting);
        }

        private bool CanJoinExecute()
        {
            return true;
        }

        private void OnHostExecute()
        {

            //Instantiate and initialize all executors
            _executor = BaseExecutor.CreateExecutor<HostExecutor>();
            _executor.Connect(this.Hostname);

            SetUpMembers();

            //Change state
            State(PartyState.Connecting);
        }

        private bool CanHostExecute()
        {
            return true;
        }


        #endregion Commands

        private void SetUpMembers()
        {
            _members = _executor.PartyMembers;
            OnPropertyChanged("Members");
            _executor.PartyMembers.CollectionChanged += (sender, e) =>
            {
                if (_executor != null)
                {
                    _members = _executor.PartyMembers;
                }
                OnPropertyChanged("Members");
            };
        }
    }
}