// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
namespace System.Windows.Forms;
 
public partial class TaskDialog
{
    private class WindowSubclassHandler : Forms.WindowSubclassHandler
    {
        private readonly TaskDialog _taskDialog;
 
        public WindowSubclassHandler(TaskDialog taskDialog)
            : base((HWND)taskDialog.OrThrowIfNull().Handle)
        {
            _taskDialog = taskDialog;
        }
 
        protected override void WndProc(ref Message m)
        {
            switch (m.MsgInternal)
            {
                case ContinueButtonClickHandlingMessage:
                    // We received the message which we posted earlier when
                    // handling a TDN_BUTTON_CLICKED notification, so we should
                    // no longer ignore such notifications.
                    // We do not forward the message to the base class.
                    _taskDialog._ignoreButtonClickedNotifications = false;
 
                    break;
 
                default:
                    base.WndProc(ref m);
                    break;
            }
        }
 
        protected override bool CanCatchWndProcException(Exception ex) => CanCatchCallbackException();
 
        protected override void HandleWndProcException(Exception ex) => HandleCallbackException(ex);
    }
}