// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows.Markup;

namespace System.Windows.Input
{
    ///<summary>
    /// An interface that allows an application author to define a method to be invoked.
    ///</summary>
    [TypeForwardedFrom("PresentationCore, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35")]
    [TypeConverter("System.Windows.Input.CommandConverter, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, Custom=null")]
    [ValueSerializer("System.Windows.Input.CommandValueSerializer, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, Custom=null")]
    public interface ICommand
    {
        /// <summary>
        /// Raised when the ability of the command to execute has changed.
        /// </summary>
        event EventHandler? CanExecuteChanged;

        /// <summary>
        /// Returns whether the command can be executed.
        /// </summary>
        /// <param name="parameter">A parameter that may be used in executing the command. This parameter may be ignored by some implementations.</param>
        /// <returns>true if the command can be executed with the given parameter and current state. false otherwise.</returns>
        bool CanExecute(object? parameter);

        /// <summary>
        /// Defines the method that should be executed when the command is executed.
        /// </summary>
        /// <param name="parameter">A parameter that may be used in executing the command. This parameter may be ignored by some implementations.</param>
        void Execute(object? parameter);
    }
}