using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace WebCam_Capture
{
 /// <summary>
 /// Summary description for UserControl1.
 /// </summary>
 [System.Drawing.ToolboxBitmap(typeof(WebCamCapture), "CAMERA.ICO")] // toolbox bitmap
 [Designer("Sytem.Windows.Forms.Design.ParentControlDesigner,System.Design", typeof(System.ComponentModel.Design.IDesigner))] // make composite
 public class WebCamCapture : System.Windows.Forms.UserControl
 {
  private System.ComponentModel.IContainer components;
  private System.Windows.Forms.Timer timer1;

  // property variables
  private int m_TimeToCapture_milliseconds = 100;
  private int m_Width = 320;
  private int m_Height = 240;
  private int mCapHwnd;
  private ulong m_FrameNumber = 0;

  // global variables to make the video capture go faster
  private WebCam_Capture.WebcamEventArgs x = new WebCam_Capture.WebcamEventArgs();
  private IDataObject tempObj;
  private System.Drawing.Image tempImg;
  private bool bStopped = true;

  // event delegate
  public delegate void WebCamEventHandler (object source, WebCam_Capture.WebcamEventArgs e);
  // fired when a new image is captured
  public event WebCamEventHandler ImageCaptured;

  #region API Declarations

  [DllImport("user32", EntryPoint="SendMessage")]
  public static extern int SendMessage(int hWnd, uint Msg, int wParam, int lParam);

  [DllImport("avicap32.dll", EntryPoint="capCreateCaptureWindowA")]
  public static extern int capCreateCaptureWindowA(string lpszWindowName, int dwStyle, int X, int Y, int nWidth, int nHeight, int hwndParent, int nID);

  [DllImport("user32", EntryPoint="OpenClipboard")]
  public static extern int OpenClipboard(int hWnd);

  [DllImport("user32", EntryPoint="EmptyClipboard")]
  public static extern int EmptyClipboard();

  [DllImport("user32", EntryPoint="CloseClipboard")]
  public static extern int CloseClipboard();

  #endregion

  #region API Constants

  public const int WM_USER = 1024;

  public const int WM_CAP_CONNECT = 1034;
  public const int WM_CAP_DISCONNECT = 1035;
  public const int WM_CAP_GET_FRAME = 1084;
  public const int WM_CAP_COPY = 1054;

  public const int WM_CAP_START = WM_USER;

  public const int WM_CAP_DLG_VIDEOFORMAT = WM_CAP_START + 41;
  public const int WM_CAP_DLG_VIDEOSOURCE = WM_CAP_START + 42;
  public const int WM_CAP_DLG_VIDEODISPLAY = WM_CAP_START + 43;
  public const int WM_CAP_GET_VIDEOFORMAT = WM_CAP_START + 44;
  public const int WM_CAP_SET_VIDEOFORMAT = WM_CAP_START + 45;
  public const int WM_CAP_DLG_VIDEOCOMPRESSION = WM_CAP_START + 46;
  public const int WM_CAP_SET_PREVIEW = WM_CAP_START + 50;

  #endregion

  #region NOTES

  /*
   * If you want to allow the user to change the display size and
   * color format of the video capture, call:
   * SendMessage (mCapHwnd, WM_CAP_DLG_VIDEOFORMAT, 0, 0);
   * You will need to requery the capture device to get the new settings
  */

  #endregion


  public WebCamCapture()
  {
   // This call is required by the Windows.Forms Form Designer.
   InitializeComponent();
  }

  /// <summary>
  /// Override the class's finalize method, so we can stop
  /// the video capture on exit
  /// </summary>
  ~WebCamCapture()
  {
   this.Stop();
  }

  /// <summary>
  /// Clean up any resources being used.
  /// </summary>
  protected override void Dispose( bool disposing )
  {
   if( disposing )
   {

    if( components != null )
     components.Dispose();
   }
   base.Dispose( disposing );
  }

  #region Component Designer generated code
  /// <summary>
  /// Required method for Designer support - do not modify
  /// the contents of this method with the code editor.
  /// </summary>
  private void InitializeComponent()
  {
   this.components = new System.ComponentModel.Container();
   this.timer1 = new System.Windows.Forms.Timer(this.components);
   //
   // timer1
   //
   this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
   //
   // WebCamCapture
   //
   this.Name = "WebCamCapture";
   this.Size = new System.Drawing.Size(342, 252);
   this.Load += new System.EventHandler(this.WebCamCapture_Load);

  }
  #endregion

  #region Control Properties

  /// <summary>
  /// The time intervale between frame captures
  /// </summary>
  public int TimeToCapture_milliseconds
  {
   get
   { return m_TimeToCapture_milliseconds; }

   set
   { m_TimeToCapture_milliseconds = value; }
  }

  /// <summary>
  /// The height of the video capture image
  /// </summary>
  public int CaptureHeight
  {
   get
   { return m_Height; }
   
   set
   { m_Height = value; }
  }

  /// <summary>
  /// The width of the video capture image
  /// </summary>
  public int CaptureWidth
  {
   get
   { return m_Width; }

   set
   { m_Width = value; }
  }

  /// <summary>
  /// The sequence number to start at for the frame number. OPTIONAL
  /// </summary>
  public ulong FrameNumber
  {
   get
   { return m_FrameNumber; }

   set
   { m_FrameNumber = value; }
  }

  #endregion

  #region Start and Stop Capture Functions

  /// <summary>
  /// Starts the video capture
  /// </summary>
  /// <param name="FrameNumber">the frame number to start at.
  /// Set to 0 to let the control allocate the frame number</param>
  public void Start(ulong FrameNum)
  {
   try
   {
    // for safety, call stop, just in case we are already running
    this.Stop();

    // setup a capture window
    mCapHwnd = capCreateCaptureWindowA("WebCap", 0, 0, 0, m_Width, m_Height, this.Handle.ToInt32(), 0);

    // connect to the capture device
    Application.DoEvents();
    SendMessage(mCapHwnd, WM_CAP_CONNECT, 0, 0);
    SendMessage(mCapHwnd, WM_CAP_SET_PREVIEW, 0, 0);

    // set the frame number
    m_FrameNumber = FrameNum;

    // set the timer information
    this.timer1.Interval = m_TimeToCapture_milliseconds;
    bStopped = false;
    this.timer1.Start();
   }

   catch (Exception excep)
   {
    MessageBox.Show("An error ocurred while starting the video capture. Check that your webcamera is connected properly and turned on.\r\n\n" + excep.Message);
    this.Stop();
   }
  }

  /// <summary>
  /// Stops the video capture
  /// </summary>
  public void Stop()
  {
   try
   {
    // stop the timer
    bStopped = true;
    this.timer1.Stop();

    // disconnect from the video source
    Application.DoEvents();
    SendMessage(mCapHwnd, WM_CAP_DISCONNECT, 0, 0);
   }

   catch (Exception excep)
   { // don't raise an error here.
   }

  }

  #endregion

  #region Video Capture Code

  /// <summary>
  /// Capture the next frame from the video feed
  /// </summary>
  private void timer1_Tick(object sender, System.EventArgs e)
  {
   try
   {
    // pause the timer
    this.timer1.Stop();

    // get the next frame;
    SendMessage(mCapHwnd, WM_CAP_GET_FRAME, 0, 0);

    // copy the frame to the clipboard
    SendMessage(mCapHwnd, WM_CAP_COPY, 0, 0);

    // paste the frame into the event args image
    if (ImageCaptured != null)
    {
     // get from the clipboard
     tempObj = Clipboard.GetDataObject();
     tempImg = (System.Drawing.Bitmap) tempObj.GetData(System.Windows.Forms.DataFormats.Bitmap);

     /*
     * For some reason, the API is not resizing the video
     * feed to the width and height provided when the video
     * feed was started, so we must resize the image here
     */
     x.WebCamImage = tempImg.GetThumbnailImage(m_Width, m_Height, null, System.IntPtr.Zero);

     // raise the event
     this.ImageCaptured(this, x);
    }  

    // restart the timer
    Application.DoEvents();
    if (! bStopped)
     this.timer1.Start();
   }

   catch (Exception excep)
   {
    MessageBox.Show("An error ocurred while capturing the video image. The video capture will now be terminated.\r\n\n" + excep.Message);
    this.Stop(); // stop the process
   }
  }

  #endregion

  private void WebCamCapture_Load(object sender, System.EventArgs e)
  {
  
  }
 }
}