Layer filtering TOC view
TOCLayerFilter.cs
// Copyright 2012 ESRI
// 
// All rights reserved under the copyright laws of the United States
// and applicable international laws, treaties, and conventions.
// 
// You may freely redistribute and use this sample code, with or
// without modification, provided you include the original copyright
// notice and use restrictions.
// 
// See the use restrictions.
// 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using ESRI.ArcGIS.ADF.CATIDs;
using ESRI.ArcGIS.ArcMapUI;
using ESRI.ArcGIS.Framework;
using ESRI.ArcGIS.Carto;
using System.Runtime.InteropServices;
using ESRI.ArcGIS.esriSystem;

namespace TOCLayerFilterCS
{
    [Guid("aede0664-ef97-4c6c-94e6-b3c6216eedc5")]
    [ClassInterface(ClassInterfaceType.None)]
    [ProgId("TOCLayerFilterCS.TOCLayerFilter")]
    public partial class TOCLayerFilter : UserControl, IContentsView3
    {
        private IApplication m_application;
        private bool m_visible;
        private object m_contextItem;
        private bool m_isProcessEvents;

        #region COM Registration Function(s)
        [ComRegisterFunction()]
        [ComVisible(false)]
        static void RegisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryRegistration(registerType);

            //
            // TODO: Add any COM registration code here
            //
        }

        [ComUnregisterFunction()]
        [ComVisible(false)]
        static void UnregisterFunction(Type registerType)
        {
            // Required for ArcGIS Component Category Registrar support
            ArcGISCategoryUnregistration(registerType);

            //
            // TODO: Add any COM unregistration code here
            //
        }

        #region ArcGIS Component Category Registrar generated code
        /// <summary>
        /// Required method for ArcGIS Component Category registration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryRegistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ContentsViews.Register(regKey);

        }
        /// <summary>
        /// Required method for ArcGIS Component Category unregistration -
        /// Do not modify the contents of this method with the code editor.
        /// </summary>
        private static void ArcGISCategoryUnregistration(Type registerType)
        {
            string regKey = string.Format("HKEY_CLASSES_ROOT\\CLSID\\{{{0}}}", registerType.GUID);
            ContentsViews.Unregister(regKey);

        }

        #endregion
        #endregion
        public TOCLayerFilter()
        {
            InitializeComponent();
        }

        #region "IContentsView3 Implementations"

        public int Bitmap
        {
          get
          {
            string bitmapResourceName = GetType().Name + ".bmp";
            System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(GetType(), bitmapResourceName);
            bmp.MakeTransparent(bmp.GetPixel(1, 1)); //alternatively use a .png with transparency
            return bmp.GetHbitmap().ToInt32();
          }
        }

        public string Tooltip
        {
          get { return "Layer Types (C#)"; }
        }

        public bool Visible
        {
            get { return m_visible; }
            set { m_visible = value; }
        }
        string IContentsView3.Name { get { return "Layer Types (C#)"; } }
        public int hWnd { get { return this.Handle.ToInt32(); } }

        public object ContextItem //last right-clicked item
        {
            get { return m_contextItem; }
            set { }//Not implemented
        }

        public void Activate(int parentHWnd, IMxDocument Document)
        {
            if (m_application == null)
            {
                m_application = ((IDocument)Document).Parent;
                if (cboLayerType.SelectedIndex < 0)
                    cboLayerType.SelectedIndex = 0; //this should refresh the list automatically
                else
                    RefreshList();

                SetUpDocumentEvent(Document as IDocument);
            }
        }

        public void BasicActivate(int parentHWnd, IDocument Document)
        {
        }
        
        public void Refresh(object item)
        {
            if (item != this)
            {
                //when items are added, removed, reordered
                tvwLayer.SuspendLayout();
                RefreshList();
                tvwLayer.ResumeLayout();
            }
        }
        public void Deactivate()
        {
            //Any clean up? 
        }

        public void AddToSelectedItems(object item) { }
        public object SelectedItem
        {
            get
            {
                //No Multiselect so return selected node
                if (tvwLayer.SelectedNode != null)
                    return tvwLayer.SelectedNode.Tag;   //Layer
                return null;
            }
            set
            {
                //Not implemented
            }
        }
        public bool ProcessEvents { set { m_isProcessEvents = value; } }
        public void RemoveFromSelectedItems(object item) { }
        public bool ShowLines
        {
            get { return tvwLayer.ShowLines; }
            set { tvwLayer.ShowLines = value; }
        }
        #endregion

        private void RefreshList()
        {
            tvwLayer.Nodes.Clear();
            UID layerFilter = null;
            if (cboLayerType.SelectedItem.Equals("Feature Layers"))
            {
                layerFilter = new UIDClass();
                layerFilter.Value = "{40A9E885-5533-11d0-98BE-00805F7CED21}"; //typeof(IFeatureLayer).GUID.ToString("B");
            }
            else if (cboLayerType.SelectedItem.Equals("Raster Layers"))
            {
                layerFilter = new UIDClass();
                layerFilter.Value = typeof(IRasterLayer).GUID.ToString("B");
            }
            else if (cboLayerType.SelectedItem.Equals("Data Layers"))
            {
                layerFilter = new UIDClass();
                layerFilter.Value = "{6CA416B1-E160-11D2-9F4E-00C04F6BC78E}"; //typeof(IDataLayer).GUID.ToString("B");
            }

            IMxDocument document = (IMxDocument)m_application.Document;
            IMaps maps = document.Maps;
            for (int i = 0; i < maps.Count; i++)
            {
                IMap map = maps.get_Item(i);
                TreeNode mapNode = tvwLayer.Nodes.Add(map.Name);
                mapNode.Tag = map;
                if (map.LayerCount > 0)
                {
                    IEnumLayer layers = map.get_Layers(layerFilter, true);
                    layers.Reset();
                    ILayer lyr;
                    while ((lyr = layers.Next()) != null)
                    {
                        TreeNode lyrNode = mapNode.Nodes.Add(lyr.Name);
                        lyrNode.Tag = lyr;
                    }

                    mapNode.ExpandAll();
                }
            }
        }

        private void cboLayerType_SelectedIndexChanged(object sender, EventArgs e)
        {
            tvwLayer.SuspendLayout();
            RefreshList();
            tvwLayer.ResumeLayout();
        }
        private void tvwLayer_NodeMouseClick(object sender, TreeNodeMouseClickEventArgs e)
        {
            if (e.Button == MouseButtons.Right)
            {
                //Set item for context menu commands to work with
                m_contextItem = e.Node.Tag;

                //Show context menu
                UID menuID = new UIDClass();
                if (e.Node.Tag is IMap) //data frame
                {
                    menuID.Value = "{F42891B5-2C92-11D2-AE07-080009EC732A}"; //Data Frame Context Menu (TOC) 
                }
                else //Layer - custom menu
                {
                    menuID.Value = "{30cb4a78-6eba-4f60-b52e-38bc02bacc89}";
                }
                ICommandBar cmdBar = (ICommandBar)m_application.Document.CommandBars.Find(menuID, false, false);
                cmdBar.Popup(0, 0);
            }
        }

        #region "Add Event Wiring for New/Open Documents"
        // Event member variables
        private IDocumentEvents_Event m_docEvents;

        // Wiring
        private void SetUpDocumentEvent(IDocument myDocument)
        {
            m_docEvents = myDocument as IDocumentEvents_Event;

            m_docEvents.OpenDocument += new IDocumentEvents_OpenDocumentEventHandler(RefreshList);
            m_docEvents.NewDocument += new IDocumentEvents_NewDocumentEventHandler(RefreshList);
        }
      
        #endregion

    }
}