DesignerTransaction.cs

using System.Security.Permissions;

namespace System.ComponentModel.Design
{
    [HostProtection(SecurityAction.LinkDemand, SharedState = true)]
    [PermissionSet(SecurityAction.InheritanceDemand, Name = "FullTrust")]
    public abstract class DesignerTransaction : IDisposable
    {
        private bool committed;

        private bool canceled;

        private bool suppressedFinalization;

        private string desc;

        public bool Canceled => canceled;

        public bool Committed => committed;

        public string Description => desc;

        protected DesignerTransaction()
            : this("")
        {
        }

        protected DesignerTransaction(string description)
        {
            desc = description;
        }

        public void Cancel()
        {
            if (!canceled && !committed)
            {
                canceled = true;
                GC.SuppressFinalize(this);
                suppressedFinalization = true;
                OnCancel();
            }
        }

        public void Commit()
        {
            if (!committed && !canceled)
            {
                committed = true;
                GC.SuppressFinalize(this);
                suppressedFinalization = true;
                OnCommit();
            }
        }

        protected abstract void OnCancel();

        protected abstract void OnCommit();

        ~DesignerTransaction()
        {
            Dispose(disposing: false);
        }

        void IDisposable.Dispose()
        {
            Dispose(disposing: true);
            if (!suppressedFinalization)
            {
                GC.SuppressFinalize(this);
            }
        }

        protected virtual void Dispose(bool disposing)
        {
            Cancel();
        }
    }
}