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

using System;
using System.ComponentModel;
using System.Collections;
using System.Runtime.Serialization;

namespace GFramework
{
    public abstract class GObject
    {
        #region Constructor

        public GObject()
        {
            m_PropertyStorage = new GPropertyStorage();
            m_BitState = new GBitVector64();
            m_BitState[StateCanRaiseEvents] = true;
        }

        #endregion

        #region Public Events

        public event GEventHandler PropertyChanging
        {
            add
            {
                Events.AddHandler(PropertyChangingEventKey, value);
            }
            remove
            {
                Events.RemoveHandler(PropertyChangingEventKey, value);
            }
        }
        public event GEventHandler PropertyChanged
        {
            add
            {
                Events.AddHandler(PropertyChangedEventKey, value);
            }
            remove
            {
                Events.RemoveHandler(PropertyChangedEventKey, value);
            }
        }

        #endregion

        #region Public Methods

        public object GetPropertyValue(int propertyKey)
        {
            bool found;
            object value = m_PropertyStorage.GetEntry(propertyKey, out found);

            if (found)
            {
                return value;
            }

            return GetDefaultPropertyValue(propertyKey);
        }
        public object GetLocalPropertyValue(int propertyKey)
        {
            bool found;
            object value = m_PropertyStorage.GetEntry(propertyKey, out found);

            if (found)
            {
                return value;
            }

            return null;
        }
        public bool ContainsLocalProperty(int propertyKey)
        {
            return GetLocalPropertyValue(propertyKey) != null;
        }
        public void ResetPropertyValue(int propertyKey)
        {
            if (ContainsLocalProperty(propertyKey) == false)
            {
                return;
            }

            SetPropertyValue(propertyKey, null);
        }
        public void SuspendEvents()
        {
            m_EventLock++;
        }
        public void ResumeEvents()
        {
            m_EventLock--;
            m_EventLock = Math.Max(0, m_EventLock);
        }

        #endregion

        #region Public Overridables

        public virtual bool GetCanRaiseEvents()
        {
            if (m_BitState[StateCanRaiseEvents] == false)
            {
                return false;
            }

            if (m_EventLock > 0)
            {
                return false;
            }

            return true;
        }
        public virtual object GetDefaultPropertyValue(int propertyKey)
        {
            return null;
        }

        #endregion

        #region Protected Overridables

        [OnDeserialized()]
        protected virtual void OnDeserialized()
        {
            m_PropertyStorage = new GPropertyStorage();
            m_BitState[StateCanRaiseEvents] = true;
        }
        protected virtual void RaiseEvent(GEventArgs args)
        {
            if (m_BitState[StateCanRaiseEvents] == false || m_EventLock > 0)
            {
                return;
            }

            GEventHandler handler = Events[args.m_Key] as GEventHandler;
            if (handler != null)
            {
                handler(args);
            }
        }
        protected virtual EventResult OnPropertyValueChanging(int propertyKey, object newValue)
        {
            if (GetCanRaiseEvents() == false)
            {
                return EventResult.Unspecified;
            }

            GPropertyChangingEventData data = new GPropertyChangingEventData(propertyKey, newValue);
            GEventArgs e = new GEventArgs(this, data, PropertyChangingEventKey, EventPropagation.Bubble);

            RaiseEvent(e);

            return e.m_Result;
        }
        protected virtual void OnPropertyValueChanged(int propertyKey)
        {
            if (GetCanRaiseEvents() == false)
            {
                return;
            }

            GPropertyEventData data = new GPropertyEventData(propertyKey);
            GEventArgs e = new GEventArgs(this, data, PropertyChangedEventKey, EventPropagation.Both);

            RaiseEvent(e);
        }
        protected virtual void SetPropertyValue(int propertyKey, object value)
        {
            EventResult result = OnPropertyValueChanging(propertyKey, value);
            if ((result & EventResult.Cancel) == EventResult.Cancel)
            {
                return;
            }

            if (value == null)
            {
                if (m_PropertyStorage.ContainsEntry(propertyKey))
                {
                    m_PropertyStorage.RemoveEntry(propertyKey);
                }
            }
            else
            {
                m_PropertyStorage.SetEntry(propertyKey, value);
            }

            OnPropertyValueChanged(propertyKey);
        }

        #endregion

        #region Protected Properties

        protected GEventStorage Events
        {
            get
            {
                if (m_Events == null)
                {
                    m_Events = new GEventStorage();
                }

                return m_Events;
            }
        }
        protected GPropertyStorage PropertyStorage
        {
            get
            {
                return m_PropertyStorage;
            }
        }

        #endregion

        #region Properties

        /// <summary>
        /// Determines whether the object is allowed to raise events.
        /// </summary>
        [DefaultValue(true)]
        public bool CanRaiseEvents
        {
            get
            {
                return m_BitState[StateCanRaiseEvents];
            }
            set
            {
                m_BitState[StateCanRaiseEvents] = value;
            }
        }
        /// <summary>
        /// Gets or sets the additional data associated with the object.
        /// </summary>
        [Browsable(false)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
        public object Tag
        {
            get
            {
                return m_Tag;
            }
            set
            {
                m_Tag = value;
            }
        }

        #endregion

        #region Fields

        internal GPropertyStorage m_PropertyStorage;

        [NonSerialized]
        internal object m_Tag;
        [NonSerialized]
        internal int m_EventLock;
        [NonSerialized]
        internal GBitVector64 m_BitState;
        [NonSerialized]
        internal GEventStorage m_Events;

        #endregion

        #region BitState Constants

        internal const ulong StateCanRaiseEvents = 1;

        #endregion

        #region Event Constants

        public const int PropertyChangingEventKey = 1;
        public const int PropertyChangedEventKey = PropertyChangingEventKey + 1;

        internal const int DefaultEventRange = 100;
        internal const int GObjectLastEventKey = DefaultEventRange;

        #endregion
    }
}