namespace System.Windows.Forms
{
    public class ToolStripDropDownItem : ToolStripItem
    {
        public virtual ToolStripItemCollection DropDownItems { get; }

        public event EventHandler DropDownOpening;
        public event EventHandler DropDownOpened;
        public event ToolStripDropDownClosedEventHandler DropDownClosed;
        public event ToolStripItemClickedEventHandler DropDownItemClicked;

        protected virtual void OnDropDownOpening(EventArgs e) => DropDownOpening?.Invoke(this, e);

        protected virtual void OnDropDownOpened(EventArgs e) => DropDownOpened?.Invoke(this, e);

        protected virtual void OnDropDownClosed(ToolStripDropDownClosedEventArgs e) => DropDownClosed?.Invoke(this, e);

        protected virtual void OnDropDownItemClicked(ToolStripItemClickedEventArgs e) => DropDownItemClicked?.Invoke(this, e);

        internal override void ResetImage()
        {
            base.ResetImage();
            foreach (ToolStripItem item in DropDownItems)
                item.ResetImage();
        }

        public override void ApplyStyle(ToolStripProfessionalRenderer r)
        {
            foreach (ToolStripItem item in DropDownItems)
                item.ApplyStyle(r);
        }

        public ToolStripDropDownItem()
        {
            DropDownItems = new ToolStripItemCollection(this);
        }
    }
}