// 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.Controls;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.SystemUI;
using ESRI.ArcGIS.esriSystem;

namespace GraphicsLayerToolControl
{
  /// <summary>
  /// This user control hosts a combobox which allow the user to control over the active graphics layer 
  /// </summary>
  public partial class GraphicsLayersListCtrl : UserControl
  {
    #region class members
    IMap m_map = null;
    UID m_uid = null;
    #endregion

    #region class constructor
    public GraphicsLayersListCtrl()
    {
      InitializeComponent();

      //initialize the UID that will be used later to get the graphics layers
      m_uid = new UIDClass();
      m_uid.Value = "{34B2EF81-F4AC-11D1-A245-080009B6F22B}"; //graphics layers category      
    }
    #endregion

    /// <summary>
    /// Get the current map and wire the ActiveViewEvents
    /// </summary>
    public IMap Map
    {
      get { return m_map; }
      set 
      {
        m_map = value;
        if (null == m_map)
          return;

        //set verbose events in order to be able to listen to the various 'ItemXXX' events 
        ((IViewManager)m_map).VerboseEvents = true;

        //register document events in order to listen to layers which gets added or removed
        ((IActiveViewEvents_Event)m_map).ItemAdded += new IActiveViewEvents_ItemAddedEventHandler(OnItemAdded);
        ((IActiveViewEvents_Event)m_map).ItemReordered += new IActiveViewEvents_ItemReorderedEventHandler(OnItemReordered);
        ((IActiveViewEvents_Event)m_map).ItemDeleted += new IActiveViewEvents_ItemDeletedEventHandler(OnItemDeleted);

        //populate the combo with a list of the graphics layers
        PopulateCombo();
      }
    }

    /// <summary>
    /// occurs when the user select an item from the combo
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void cmbGraphicsLayerList_SelectedIndexChanged(object sender, EventArgs e)
    {
      if (null == m_map)
        return;

      //get the basic graphics layer from the map
      ILayer activeLayer = m_map.BasicGraphicsLayer as ILayer;
      //if the name of the selected item is the basic graphics layer, make it the active graphics layer
      if (activeLayer.Name == cmbGraphicsLayerList.SelectedItem.ToString())
      {
        m_map.ActiveGraphicsLayer = m_map.BasicGraphicsLayer as ILayer;
        return;
      }
      //iterate through the graphics layers
      IEnumLayer layers = GetGraphicsLayersList();
      if (null == layers)
        return;

      layers.Reset();
      ILayer layer = null;
      while ((layer = layers.Next()) != null)
      {
        if (layer is IGroupLayer)
          continue;

        if (layer is IGraphicsLayer)
        {
          //make the select item the active graphics layer
          if (layer.Name == cmbGraphicsLayerList.SelectedItem.ToString())
            m_map.ActiveGraphicsLayer = layer;
        }
      } 
    }

    /// <summary>
    /// get the list of all graphics layers in the map
    /// </summary>
    /// <returns></returns>
    private IEnumLayer GetGraphicsLayersList()
    {
      IEnumLayer layers = null;
      if (null == m_map || 0 == m_map.LayerCount)
        return null;

      try
      {
        layers = m_map.get_Layers(m_uid, true);
      }
      catch (Exception ex)
      {
        System.Diagnostics.Trace.WriteLine(ex.Message);
        return null;
      }

      return layers;
    }
    
    /// <summary>
    /// list the graphics layers in the combo and select the active graphics layer
    /// </summary>
    private void PopulateCombo()
    {
      if (null == m_map)
        return;

      //clear the items list of the combo
      cmbGraphicsLayerList.Items.Clear();

      //add the basic graphics layer name
      cmbGraphicsLayerList.Items.Add(((ILayer)m_map.BasicGraphicsLayer).Name);

      //get the active graphics layer
      ILayer activeLayer = m_map.ActiveGraphicsLayer;

      //get the list of all graphics layers in the map
      IEnumLayer layers = GetGraphicsLayersList();
      if (null != layers)
      {

        //add the layer names to the combo
        layers.Reset();
        ILayer layer = null;
        while ((layer = layers.Next()) != null)
        {
          cmbGraphicsLayerList.Items.Add(layer.Name);
        }
      }
      //set the selected item to be the active layer
      cmbGraphicsLayerList.SelectedItem = activeLayer.Name;
    }

    /// <summary>
    /// occurs when a layer is being deleted from the map
    /// </summary>
    /// <param name="Item"></param>
    void OnItemDeleted(object Item)
    {
      PopulateCombo();
    }

    /// <summary>
    /// occurs when a layer is being reordered in the TOC
    /// </summary>
    /// <param name="Item"></param>
    /// <param name="toIndex"></param>
    void OnItemReordered(object Item, int toIndex)
    {
      PopulateCombo();
    }

    /// <summary>
    /// occurs when a layer is being added to the map
    /// </summary>
    /// <param name="Item"></param>
    void OnItemAdded(object Item)
    {
      PopulateCombo();
    }
  }
}