SystemBarViewModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Input;

namespace Worksly
{
    class SystemBarViewModel
    {
        /// <summary>
        /// Shows a window, if none is already open.
        /// </summary>
        public ICommand ShowWindowCommand
        {
            get
            {
                return new DelegateCommand
                {
                    //CanExecuteFunc = () => Application.Current.MainWindow == null,
                    CommandAction = () =>
                    {
                        //Application.Current.MainWindow = new MainWindow();
                        Application.Current.MainWindow.Show();
                        Application.Current.MainWindow.Activate();
                    }
                };
            }
        }

        //public ICommand CheckForUpdateCommand
        //{
        //    get
        //    {
        //        return new DelegateCommand
        //        {
        //            //CanExecuteFunc = () => Application.Current.MainWindow == null,
        //            CommandAction = () =>
        //            {
        //                //Application.Current.MainWindow = new MainWindow();
        //                HelperTags.InstallUpdateSyncWithInfo();
        //            }
        //        };
        //    }
        //}

        /// <summary>
        /// Hides the main window. This command is only enabled if a window is open.
        /// </summary>
        public ICommand HideWindowCommand
        {
            get
            {
                return new DelegateCommand
                {
                    CommandAction = () => Application.Current.MainWindow.Hide(),
                    CanExecuteFunc = () => Application.Current.MainWindow != null
                };
            }
        }

        /// <summary>
        /// Hides the main window if open and opens the EOD window
        /// </summary>
        public ICommand EODWindowCommand
        {
            get
            {
                return new DelegateCommand
                {
                    CommandAction = () =>
                    {
                        if (Application.Current.Windows.OfType<EODWindow>().Any()) { return; }
                        if (Application.Current.MainWindow != null) { Application.Current.MainWindow.Hide(); }
                        EODWindow window1 = new EODWindow();
                        window1.Show();
                    }
                };
            }
        }

        /// <summary>
        /// Open settings menu
        /// </summary>
        public ICommand SettingsWindow
        {
            get
            {
                return new DelegateCommand
                {
                    CommandAction = () =>
                    {
                        Settings window1;
                        if (Application.Current.Windows.OfType<Settings>().Any())
                        {
                            window1 = Application.Current.Windows.OfType<Settings>().First();
                            window1.Show();
                            window1.Activate();
                        }
                        window1 = new Settings();
                        window1.Show();
                    }
                };
            }
        }

        /// <summary>
        /// Shuts down the application.
        /// </summary>
        public ICommand ExitApplicationCommand
        {
            get
            {
                return new DelegateCommand { CommandAction = () => Application.Current.Shutdown() };
            }
        }
    }


    /// <summary>
    /// Simplistic delegate command for the demo.
    /// </summary>
    public class DelegateCommand : ICommand
    {
        public Action CommandAction { get; set; }
        public Func<bool> CanExecuteFunc { get; set; }

        public void Execute(object parameter)
        {
            CommandAction();
        }

        public bool CanExecute(object parameter)
        {
            return CanExecuteFunc == null || CanExecuteFunc();
        }

        public event EventHandler CanExecuteChanged
        {
            add { CommandManager.RequerySuggested += value; }
            remove { CommandManager.RequerySuggested -= value; }
        }
    }
}