Custom scene navigation commands
ZoomOut.cs
// Copyright 2010 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.Drawing;
using ESRI.ArcGIS.Analyst3D;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.ADF.BaseClasses;
using ESRI.ArcGIS.ADF.CATIDs;
using System.Runtime.InteropServices;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Display;

namespace sceneTools
{
  [ClassInterface(ClassInterfaceType.None)]
  [Guid("3D3C8C68-7B65-4441-B614-792D5606FF8D")]

  public sealed class ZoomOut : BaseTool
  {
    [DllImport("user32")] public static extern int ReleaseCapture(int hwnd); 
    [DllImport("user32")] public static extern int SetCapture(int hwnd); 
    [DllImport("user32")] public static extern int GetCapture(int fuFlags);
    [DllImport("user32")] public static extern int GetWindowRect(int hwnd, ref Rectangle lpRect);

        #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

    private System.Windows.Forms.Cursor m_pCursor;
    private ISceneHookHelper m_pSceneHookHelper;
    private long m_lMouseX, m_lMouseY;
    private bool m_bInUse;
        private INewEnvelopeFeedback m_feedBack;
        private IPoint m_point;

    public ZoomOut()
    {
      base.m_category = "Sample_SceneControl(C#)";
      base.m_caption = "Zoom Out";
      base.m_toolTip = "Zoom Out";
      base.m_name = "Sample_SceneControl(C#)/Zoom Out";
      base.m_message = "Zooms in out the scene";

      //Load resources
      string[] res = GetType().Assembly.GetManifestResourceNames();
      if(res.GetLength(0) > 0)
      {
        base.m_bitmap = new System.Drawing.Bitmap(GetType().Assembly.GetManifestResourceStream("sceneTools.zoomout.bmp"));
      }
      m_pCursor = new System.Windows.Forms.Cursor(GetType().Assembly.GetManifestResourceStream("sceneTools.ZOOMOUT.CUR"));
    
      m_pSceneHookHelper = new SceneHookHelperClass ();
    }

    public override bool Enabled
    {
      get
      {
        if(m_pSceneHookHelper.Scene == null)
          return false;
        else
          return true;
      }
    }

    public override void OnCreate(object hook)
    {
      m_pSceneHookHelper.Hook = hook;
    }

    public override int Cursor
    {
      get
      {
        return m_pCursor.Handle.ToInt32();
      }
    }

    public override bool Deactivate()
    {
      return true;
    }

    public override void OnKeyDown(int keyCode, int Shift)
    {
      if(m_bInUse == true)
      {
        if(keyCode == 27) //If ESC was pressed 
        {
          //Redraw the scene viewer
          ISceneViewer pSceneViewer = (ISceneViewer) m_pSceneHookHelper.ActiveViewer;
          pSceneViewer.Redraw(true);

          ReleaseCapture(m_pSceneHookHelper.ActiveViewer.hWnd);

          m_bInUse = false;
        }
      }
    }

    public override void OnMouseDown(int Button, int Shift, int X, int Y)
    {
      //Initialize mouse coordinates
      m_bInUse = true;
      m_lMouseX = X;
      m_lMouseY = Y;
            
      //Get the scene viewer
      ISceneViewer pSceneViewer = (ISceneViewer) m_pSceneHookHelper.ActiveViewer;

      SetCapture(m_pSceneHookHelper.ActiveViewer.hWnd);

            //Create a point in map coordinates
            IActiveView pActiveView = (IActiveView)m_pSceneHookHelper.Scene;
            m_point = pActiveView.ScreenDisplay.DisplayTransformation.ToMapPoint(X, Y);

    }

    public override void OnMouseMove(int Button, int Shift, int X, int Y)
    {
      if(!m_bInUse) return;

            //Get the focus map
            IActiveView pActiveView = (IActiveView)m_pSceneHookHelper.Scene;

            //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 override void OnMouseUp(int Button, int Shift, int X, int Y)
    {
      if(!m_bInUse) return;

            try
            {
                if (GetCapture(m_pSceneHookHelper.ActiveViewer.hWnd) != 0)
                    ReleaseCapture(m_pSceneHookHelper.ActiveViewer.hWnd);

                //Get the scene viewer's camera
                ICamera pCamera = (ICamera)m_pSceneHookHelper.Camera;

                //Get the scene graph
                ISceneGraph pSceneGraph = (ISceneGraph)m_pSceneHookHelper.SceneGraph;

                //Create envelope
                IEnvelope pEnvelope;
                CreateEnvelope(X, Y, out pEnvelope);

                IPoint pPoint;
                object pOwner, pObject;

                if (pEnvelope.Width == 0 || pEnvelope.Height == 0)
                {
                    //Translate screen coordinates into a 3D point
                    pSceneGraph.Locate(pSceneGraph.ActiveViewer, X, Y, esriScenePickMode.esriScenePickAll, true,
                        out pPoint, out pOwner, out pObject);

                    //Set camera target and zoom in
                    pCamera.Target = pPoint;
                    pCamera.Zoom(1.3333333333333);
                }
                else
                {
                    //Get dimension of the scene viewer window
                    Rectangle rect;
                    rect = new Rectangle();

                    if (GetWindowRect(m_pSceneHookHelper.ActiveViewer.hWnd, ref rect) == 0) return;

                    //If perspective (3D) view
                    if (pCamera.ProjectionType == esri3DProjectionType.esriPerspectiveProjection)
                    {
                        double dWidth, dHeight;

                        dWidth = Math.Abs(rect.Right - rect.Left) * (Math.Abs(rect.Right - rect.Left) / pEnvelope.Width);
                        dHeight = Math.Abs(rect.Top - rect.Bottom) * (Math.Abs(rect.Top - rect.Bottom) / pEnvelope.Height);

                        pPoint = new PointClass();
                        pPoint.PutCoords(pEnvelope.XMin + (pEnvelope.Width / 2), pEnvelope.YMin + (pEnvelope.Height / 2));

                        //Redimension envelope based on scene viewer dimensions
                        pEnvelope.XMin = pPoint.X - (dWidth / 2);
                        pEnvelope.YMin = pPoint.Y - (dHeight / 2);
                        pEnvelope.Width = dWidth;
                        pEnvelope.Height = dHeight;

                        //Zoom camera to the envelope
                        pCamera.ZoomToRect(pEnvelope);
                    }
                    else
                    {
                        //Translate screen coordinates into a 3D point
                        pSceneGraph.Locate(pSceneGraph.ActiveViewer, (int)(pEnvelope.XMin + (pEnvelope.Width / 2)),
                            (int)(pEnvelope.YMin + (pEnvelope.Height / 2)), esriScenePickMode.esriScenePickAll, true,
                            out pPoint, out pOwner, out pObject);

                        //Set camera target
                        pCamera.Target = pPoint;

                        double dx, dy;
                        dx = pEnvelope.Width;
                        dy = pEnvelope.Height;

                        //Determine zoom factor
                        if (dx > 0 && dy > 0)
                        {
                            dx = Math.Abs(rect.Right - rect.Left) / dx;
                            dy = Math.Abs(rect.Top - rect.Bottom) / dy;

                            if (dx < dy)
                                pCamera.Zoom(dx);
                            else
                                pCamera.Zoom(dy);
                        }
                        else
                            pCamera.Zoom(1.3333333333333);
                    }
                }
            }
            finally
            {
                //Redraw the scene viewer
                ISceneViewer pSceneViewer = (ISceneViewer)m_pSceneHookHelper.ActiveViewer;
                pSceneViewer.Redraw(true);


                m_bInUse = false;
            }
    }

    public void CreateEnvelope(int X, int Y, out IEnvelope pEnvelope)
    {
      //Create envelope based upon the initial
      //and current mouse coordinates
      pEnvelope = new EnvelopeClass();
      if((double)m_lMouseX <= (double)X)
      {
        pEnvelope.XMin = (double) m_lMouseX;
        pEnvelope.XMax = (double) X;
      }
      else
      {
        pEnvelope.XMin = (double) X;
        pEnvelope.XMax = (double) m_lMouseX;
      }

      if((double) m_lMouseY <= (double) Y)
      {
        pEnvelope.YMin = (double) m_lMouseY;
        pEnvelope.YMax = (double) Y;
      }
      else
      {
        pEnvelope.YMin = (double) Y;
        pEnvelope.YMax = (double) m_lMouseY;
      }
    }

    public void DrawRectangle(IEnvelope pEnvelope)
    {
      //Get the scene viewer
      ISceneViewer pSceneViewer = (ISceneViewer) m_pSceneHookHelper.ActiveViewer;

            using (Graphics myGraphics = Graphics.FromHdc((IntPtr)m_pSceneHookHelper.ActiveViewer.hDC))
            {
                using (Brush brush = new SolidBrush(Color.Transparent))//hollow brush
                {
                    //GDI+ call to fill a rectangle with a hollow brush
                    myGraphics.FillRectangle(brush, (int)pEnvelope.XMin, (int)pEnvelope.YMin,
                        (int)pEnvelope.Width, (int)pEnvelope.Height);
                }

                using (Pen pen = new System.Drawing.Pen(Color.Black, 2)) //A solid, width of 2 black pen
                {
                    //GDI+ call to draw a rectangle with a specified pen 
                    myGraphics.DrawRectangle(pen, (int)pEnvelope.XMin, (int)pEnvelope.YMin,
                        (int)pEnvelope.Width, (int)pEnvelope.Height);
                }
            }

    }
  }
}