xenadmin/XenAdmin/Controls/NonReopeningContextMenuStrip.cs

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// A ContextMenuStrip which doesn't reopen immediately after closing.
// This is to fix CA-25239.

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.ComponentModel;

namespace XenAdmin.Controls
{
    public class NonReopeningContextMenuStrip : ContextMenuStrip
    {
        private static TimeSpan Epsilon = TimeSpan.FromMilliseconds(200);  // the time within which we are not allowed to reopen

        private DateTime lastClosedTime = DateTime.MinValue;

        public NonReopeningContextMenuStrip()
            : base()
        {
            InitEvents();
        }

        public NonReopeningContextMenuStrip(IContainer container)
            : base(container)
        {
            InitEvents();
        }

        protected void InitEvents()
        {
            this.Opening += new CancelEventHandler(NonReopeningContextMenuStrip_Opening);
            this.Closed += new ToolStripDropDownClosedEventHandler(NonReopeningContextMenuStrip_Closed);
        }

        protected override void Dispose(bool disposing)
        {
            if(disposing)
            {
                Opening -= NonReopeningContextMenuStrip_Opening;
                Closed -= NonReopeningContextMenuStrip_Closed;
            }
            base.Dispose(disposing);
        }

        public bool CanOpen
        {
            get
            {
                TimeSpan timeSpan = DateTime.Now - lastClosedTime;
                return (timeSpan < TimeSpan.Zero || timeSpan > Epsilon);
            }
        }

        private void NonReopeningContextMenuStrip_Opening(object sender, CancelEventArgs e)
        {
            if (!CanOpen)
                e.Cancel = true;
        }

        private void NonReopeningContextMenuStrip_Closed(object sender, ToolStripDropDownClosedEventArgs e)
        {
            lastClosedTime = DateTime.Now;
        }

    }
}