Custom map navigation commands
ZoomOut.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 ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.Display;
using ESRI.ArcGIS.SystemUI;
using ESRI.ArcGIS.ADF.CATIDs;
using System.Runtime.InteropServices;

namespace PanZoom
{
  [ClassInterface(ClassInterfaceType.None)]
  [Guid("03079006-888A-4691-941A-7B16F35E2C1E")]

  public class ZoomOut : ICommand, ITool
  {
        #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);
            ControlsCommands.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);
            ControlsCommands.Unregister(regKey);

        }

        #endregion
        #endregion

    [DllImport("gdi32.dll")]
    static extern bool DeleteObject(IntPtr hObject);
    private System.Drawing.Bitmap m_bitmap;
    private IntPtr m_hBitmap;
    private IHookHelper m_pHookHelper;
    private INewEnvelopeFeedback m_feedBack;
    private IPoint m_point;
    private Boolean m_isMouseDown;
    private System.Windows.Forms.Cursor m_zoomOutCur;
    private System.Windows.Forms.Cursor m_moveZoomOutCur;

    public ZoomOut()
    {
      //Load resources
      string[] res = GetType().Assembly.GetManifestResourceNames();
      if(res.GetLength(0) > 0)
      {
        m_bitmap = new System.Drawing.Bitmap(GetType().Assembly.GetManifestResourceStream(GetType(), "ZoomOut.bmp"));
        if(m_bitmap != null)
        {
          m_bitmap.MakeTransparent(m_bitmap.GetPixel(1,1));
          m_hBitmap = m_bitmap.GetHbitmap();
        }
      }
      m_pHookHelper = new HookHelperClass ();
    }
        
    ~ZoomOut()
    {
      if(m_hBitmap.ToInt32() != 0)
        DeleteObject(m_hBitmap);
    }
  
    #region ICommand Members

    public void OnClick()
    {
    }

    public string Message
    {
      get
      {
        return "Zooms the display out by rectangle or single click";
      }
    }

    public int Bitmap
    {
      get
      {
        return m_hBitmap.ToInt32();
      }
    }

    public void OnCreate(object hook)
    {
      m_pHookHelper.Hook = hook;
      m_zoomOutCur = new System.Windows.Forms.Cursor(GetType().Assembly.GetManifestResourceStream(GetType(), "ZoomOut.cur"));
      m_moveZoomOutCur = new System.Windows.Forms.Cursor(GetType().Assembly.GetManifestResourceStream(GetType(), "MoveZoomOut.cur"));
    }

    public string Caption
    {
      get
      {
        return "Zoom Out";
      }
    }

    public string Tooltip
    {
      get
      {
        return "Zoom Out";
      }
    }

    public int HelpContextID
    {
      get
      {
        // TODO:  Add ZoomOut.HelpContextID getter implementation
        return 0;
      }
    }

    public string Name
    {
      get
      {
        return "Sample_Pan/Zoom_Zoom Out";
      }
    }

    public bool Checked
    {
      get
      {
        return false;
      }
    }

    public bool Enabled
    {
      get
      {
        if(m_pHookHelper.FocusMap == null) return false;

        return true;
      }
    }

    public string HelpFile
    {
      get
      {
        // TODO:  Add ZoomOut.HelpFile getter implementation
        return null;
      }
    }

    public string Category
    {
      get
      {
        return "Sample_Pan/Zoom";
      }
    }

    #endregion
  
    #region ITool Members

    public void OnMouseDown(int button, int shift, int x, int y)
    {
      if(m_pHookHelper.ActiveView == null) return;

      //If the active view is a page layout
      if(m_pHookHelper.ActiveView is IPageLayout)
      {
        //Create a point in map coordinates
        IPoint pPoint = (IPoint) m_pHookHelper.ActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);

        //Get the map if the point is within a data frame
        IMap pMap = m_pHookHelper.ActiveView.HitTestMap(pPoint);

        if(pMap == null) return;

        //Set the map to be the page layout's focus map
        if(pMap != m_pHookHelper.FocusMap)
        {
          m_pHookHelper.ActiveView.FocusMap = pMap;
          m_pHookHelper.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewGraphics, null, null);
        }
      }
      //Create a point in map coordinates
      IActiveView pActiveView = (IActiveView) m_pHookHelper.FocusMap;
      m_point = pActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y);
      m_isMouseDown = true;
    }

    public void OnMouseMove(int button, int shift, int x, int y)
    {
      if(!m_isMouseDown) return;

      //Get the focus map
      IActiveView pActiveView = (IActiveView) m_pHookHelper.FocusMap;

      //Start an envelope feedback
      if(m_feedBack == null)
      {
        m_feedBack = new NewEnvelopeFeedbackClass();
        m_feedBack.Display = pActiveView.ScreenDisplay;
        m_feedBack.Start(m_point);
      }

      //Move the envelope feedback
      m_feedBack.MoveTo(pActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(x, y));
    }

    public void OnMouseUp(int button, int shift, int x, int y)
    {
      if(!m_isMouseDown) return;

      IEnvelope pEnvelope;
      IEnvelope pFeedEnvelope;

      double newWidth, newHeight;
      
      //Get the focus map
      IActiveView pActiveView = (IActiveView) m_pHookHelper.FocusMap;

      //If an envelope has not been tracked
      if(m_feedBack == null)
      {
        //Zoom out from the mouse click
        pEnvelope = pActiveView.Extent;
        pEnvelope.Expand(2, 2, true);
        pEnvelope.CenterAt(m_point);
      }
      else
      {
        //Stop the envelope feedback
        pFeedEnvelope = m_feedBack.Stop();

        //Exit if the envelope height or width is 0
        if(pFeedEnvelope.Width == 0 || pFeedEnvelope.Height == 0)
        {
          m_feedBack = null;
          m_isMouseDown = false;
        }

        newWidth = pActiveView.Extent.Width * (pActiveView.Extent.Width / pFeedEnvelope.Width);
        newHeight = pActiveView.Extent.Height * (pActiveView.Extent.Height / pFeedEnvelope.Height);

        //Set the new extent coordinates
        pEnvelope = new EnvelopeClass();
        pEnvelope.PutCoords(pActiveView.Extent.XMin - ((pFeedEnvelope.XMin - pActiveView.Extent.XMin) * (pActiveView.Extent.Width / pFeedEnvelope.Width)), 
          pActiveView.Extent.YMin - ((pFeedEnvelope.YMin - pActiveView.Extent.YMin) * (pActiveView.Extent.Height / pFeedEnvelope.Height)),
          (pActiveView.Extent.XMin - ((pFeedEnvelope.XMin - pActiveView.Extent.XMin) * (pActiveView.Extent.Width / pFeedEnvelope.Width))) + newWidth,
          (pActiveView.Extent.YMin - ((pFeedEnvelope.YMin - pActiveView.Extent.YMin) * (pActiveView.Extent.Height / pFeedEnvelope.Height))) + newHeight);
      }

      //Set the new extent
      pActiveView.Extent = pEnvelope;

      //Refresh the active view
      pActiveView.Refresh();
      m_feedBack = null;
      m_isMouseDown = false;
    }

    public void OnKeyDown(int keyCode, int shift)
    {
      if(m_isMouseDown)
      {
        if(keyCode == 27) //ESC key
        {
          m_feedBack = null;
          m_isMouseDown = false;
          m_pHookHelper.ActiveView.PartialRefresh(esriViewDrawPhase.esriViewForeground, null, null);
        }
      }
    }

    public void OnKeyUp(int keyCode, int shift)
    {
      // TODO:  Add ZoomOut.OnKeyUp implementation
    }

    public int Cursor
    {
      get
      {
        if(m_isMouseDown)
          return m_moveZoomOutCur.Handle.ToInt32();
        else
          return m_zoomOutCur.Handle.ToInt32();
      }
    }

    public bool OnContextMenu(int x, int y)
    {
      // TODO:  Add ZoomOut.OnContextMenu implementation
      return false;
    }

    public bool Deactivate()
    {
      return true;
    }

    public void Refresh(int hdc)
    {
      // TODO:  Add ZoomOut.Refresh implementation
    }

    public void OnDblClick()
    {
      // TODO:  Add ZoomOut.OnDblClick implementation
    }

    #endregion
  }
}