GMarkupLabel - A C# Windows Forms control to display XML-formatted text

using System;

namespace GFramework
{
    public abstract class GNode : GDisposableObject, IGEventListener, IComparable
    {
        #region Constructor

        public GNode()
        {
        }

        #endregion

        #region Interface Implementation

        #region IGEventListener

        void IGEventListener.PreviewEvent(GEventArgs e)
        {
            OnPreviewEvent(e);
        }

        #endregion

        #region IComparable

        public int CompareTo(object obj)
        {
            GNode node = obj as GNode;
            if (node == null)
            {
                throw new ArgumentException("May compare to GNode instances only.");
            }

            return CompareCore(node);
        }

        #endregion

        #endregion

        #region Public Methods

        public GNode GetAncestor(int level)
        {
            if (level <= 0)
            {
                return null;
            }

            GNode parent = m_Parent;
            level--;

            while (level > 0)
            {
                parent = parent.m_Parent;
                level--;
            }

            return parent;
        }

        #endregion

        #region Public Overrides

        public override bool GetCanRaiseEvents()
        {
            if (m_Root != null && m_Root.m_InitializeLock > 0)
            {
                return false;
            }

            return base.GetCanRaiseEvents();
        }

        #endregion

        #region Protected Overridables

        protected internal virtual void OnParentChanged(GElement parent)
        {
            m_Parent = parent;

            if (m_Parent == null)
            {
                SetRoot(null);
            }
        }
        protected internal virtual void SetRoot(GRootElement root)
        {
            m_Root = root;
        }
        protected internal virtual void BubbleEvent(GEventArgs e)
        {
            //no parent to bubble to
            if (m_Parent == null)
            {
                return;
            }

            //bubble process has been explicitly canceled
            if ((e.m_Result & EventResult.Cancel) == EventResult.Cancel)
            {
                return;
            }

            e.m_Sender = this;
            m_Parent.OnBubbleEvent(e);
        }
        protected internal virtual void TunnelEvent(GEventArgs e)
        {
        }

        protected internal virtual void OnBubbleEvent(GEventArgs e)
        {
            BubbleEvent(e);
        }
        protected internal virtual void OnTunnelEvent(GEventArgs e)
        {
            TunnelEvent(e);
        }
        protected virtual void OnPreviewEvent(GEventArgs e)
        {
        }

        protected virtual int CompareCore(GNode node)
        {
            return 0;
        }

        #endregion

        #region Protected Overrides

        protected override void RaiseEvent(GEventArgs args)
        {
            if ((args.m_Propagation & EventPropagation.Bubble) == EventPropagation.Bubble)
            {
                //notify parent chain fo an event
                BubbleEvent(args);

                if ((args.m_Result & EventResult.Cancel) == EventResult.Cancel)
                {
                    return;
                }
            }

            if ((args.m_Propagation & EventPropagation.Tunnel) == EventPropagation.Tunnel)
            {
                //notify parent chain fo an event
                TunnelEvent(args);

                if ((args.m_Result & EventResult.Cancel) == EventResult.Cancel)
                {
                    return;
                }
            }

            base.RaiseEvent(args);
        }

        #endregion

        #region Properties

        public GNode Parent
        {
            get
            {
                return m_Parent;
            }
        }
        public GRootElement Root
        {
            get
            {
                return m_Root;
            }
        }

        #endregion

        #region Fields

        [NonSerialized]
        internal GNode m_Parent;
        [NonSerialized]
        internal GRootElement m_Root;

        #endregion
    }
}