source: extensions/PiwigoLib/PiwigoWpf/Command/DelegateCommand.cs @ 11926

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

namespace Com.Piwigo.Wpf.Command
{
    public class DelegateCommand : ICommand
    {
        private readonly Predicate<object> _canExecute;
        private readonly Action<object> _execute;
        private Boolean _isRunning;

        public event EventHandler CanExecuteChanged;

        public DelegateCommand(Action<object> execute)
            : this(execute, null)
        {
        }

        public DelegateCommand(Action<object> execute,
                       Predicate<object> canExecute)
        {
            _execute = execute;
            _canExecute = canExecute;
            _isRunning = false;
        }

        public bool CanExecute(object parameter)
        {
            if ((_isRunning) || (_canExecute == null))
            {
                return false;
            }

            return _canExecute(parameter);
        }

        public void Execute(object parameter)
        {
            _isRunning = true;
            RaiseCanExecuteChanged();
            _execute(parameter);
            _isRunning = false;
            RaiseCanExecuteChanged();
        }

        public void RaiseCanExecuteChanged()
        {
            if (CanExecuteChanged != null)
            {
                CanExecuteChanged(this, EventArgs.Empty);
            }
        }
    }
}