NavigationButton.cs

using System;
using System.Windows.Forms;
using System.Drawing;
using System.ComponentModel;

namespace iMon.XBMC
{
    internal class NavigationButton : Button
    {
        #region Private variables

        private int defaultImageIndex;
        private int hoverImageIndex;
        private int activeImageIndex;

        private int currentImageIndex;

        #endregion

        #region Public variables

        [DefaultValue(-1), Browsable(true)]
        public int DefaultImageIndex 
        {
            get { return this.defaultImageIndex; }
            set
            {
                if (value < -1)
                {
                    value = -1;
                }

                this.defaultImageIndex = value;
            }
        }

        [Browsable(false)]
        public Image DefaultImage 
        {
            get 
            {
                if (this.ImageList == null || this.defaultImageIndex < 0 || this.defaultImageIndex >= this.ImageList.Images.Count) 
                {
                    return null;
                }
                
                return this.ImageList.Images[this.defaultImageIndex]; 
            }
        }

        [DefaultValue(-1), Browsable(true)]
        public int HoverImageIndex
        {
            get { return this.hoverImageIndex; }
            set
            {
                if (value < -1)
                {
                    value = -1;
                }

                this.hoverImageIndex = value;
            }
        }

        [Browsable(false)]
        public Image HoverImage
        {
            get 
            {
                if (this.ImageList == null || this.hoverImageIndex < 0 || this.hoverImageIndex >= this.ImageList.Images.Count) 
                {
                    return null;
                }

                return this.ImageList.Images[this.hoverImageIndex]; 
            }
        }

        [DefaultValue(-1), Browsable(true)]
        public int ActiveImageIndex
        {
            get { return this.activeImageIndex; }
            set
            {
                if (value < -1)
                {
                    value = -1;
                }

                this.activeImageIndex = value;
            }
        }

        [Browsable(false)]
        public Image ActiveImage
        {
            get 
            {
                if (this.ImageList == null || this.activeImageIndex < 0 || this.activeImageIndex >= this.ImageList.Images.Count) 
                {
                    return null;
                }

                return this.ImageList.Images[this.activeImageIndex]; 
            }
        }

        #endregion

        #region Constructors

        public NavigationButton()
        { 
            this.defaultImageIndex = -1;
            this.hoverImageIndex = -1;
            this.activeImageIndex = -1;
            this.currentImageIndex = -1;
        }

        #endregion

        #region Public functions

        public void Activate()
        {
            if (this.activeImageIndex < 0 || this.ImageList == null || this.ImageList.Images.Count <= this.activeImageIndex)
            {
                return;
            }

            this.ImageIndex = this.activeImageIndex;
            this.currentImageIndex = this.activeImageIndex;
        }

        public void Deactivate()
        {
            if (this.defaultImageIndex < 0 || this.ImageList == null || this.ImageList.Images.Count <= this.defaultImageIndex)
            {
                return;
            }

            this.ImageIndex = this.defaultImageIndex;
        }

        #endregion

        #region Overrides of Button

        protected override void OnClick(EventArgs e)
        {
            this.Activate();

            base.OnClick(e);
        }

        protected override void OnMouseEnter(EventArgs e)
        {
            if (this.hoverImageIndex < 0 || this.ImageList == null || this.ImageList.Images.Count <= this.hoverImageIndex)
            {
                base.OnMouseEnter(e);
                return;
            }

            this.currentImageIndex = this.ImageIndex;
            this.ImageIndex = this.hoverImageIndex;
        }

        protected override void OnMouseLeave(EventArgs e)
        {
            if (this.currentImageIndex < 0 || this.ImageList == null || this.ImageList.Images.Count <= this.currentImageIndex)
            {
                base.OnMouseLeave(e);
                return;
            }

            this.ImageIndex = this.currentImageIndex;
            this.currentImageIndex = -1;
        }

        #endregion
    }
}