using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

using System.Runtime.InteropServices;
using ORiN2.interop.CAO;

namespace QRCode
{
    public partial class Form1 : Form
    {
        private delegate void SetTextCallback(string msg);  // delegate for processing OnMessage
        private CaoEngine caoEng;
        private CaoWorkspaces caoWss;
        private CaoWorkspace caoWs;
        private CaoVariable caoVar;
        
        // Scanner objects
        private CaoController caoCtrl;

        //-----------------------------Initialization----------------------------
        public Form1()
        {
            InitializeComponent();

            //CreateEngine
            caoEng = new CaoEngine();
            caoWss = caoEng.Workspaces;
            caoWs = caoWss.Item(0);

            cmdConnectScanner.Enabled = true;
            btnRead.Enabled = false;
            
            cmbMode.SelectedIndex = 0;
        }

        // ---------------------------------------------------------------
        // Connect with the Scanner
        // ---------------------------------------------------------------
        private void cmdConnectScanner_Click(object sender, EventArgs e)
        {
            String strCom = "";
            bool bReadData = false;
            if(cmbMode.SelectedItem.ToString()=="EVENT")
            {
                strCom = "5";
                bReadData = false;  // Disable ReadData button
            }
            else{
                strCom = "4";
                bReadData = true;   // Enable ReadData button
            }

            String strConnOpt = "Conn=com:" + numudCom.Value.ToString() + ":38400:N:8:1,Mode=" + strCom + ",Protocol=0:0:0,Timeout=1000";
            try
            {
                // Connect with the QR Scanner
                caoCtrl = caoWs.AddController("QRCode", "CaoProv.DENSO.QRCode", "", strConnOpt);
       
                // Enable command buttons
                cmdConnectScanner.Enabled = false;
                cmdDisconnectScanner.Enabled = true;
                cmbMode.Enabled = false;
                numudCom.Enabled = false;

                // Add event handler for OnMessage
                caoCtrl.OnMessage += new _ICaoControllerEvents_OnMessageEventHandler(OnMessage);

                // Get variable object
                caoVar = caoCtrl.AddVariable("ReadData", "");
                // Enable/Disable ReadData button
                btnRead.Enabled = bReadData;
            }
            catch (Exception ex)
            {
                cmdDisconnectScanner_Click(sender, e);
                MessageBox.Show(ex.Message);
            }
        }
        
        // ---------------------------------------------------------------
        // Disconnect from the Scanner
        // ---------------------------------------------------------------
        private void cmdDisconnectScanner_Click(object sender, EventArgs e)
        {
            if (caoVar != null)
            {
                Marshal.ReleaseComObject(caoVar);
                caoVar = null;
            }
            
            // Disconnect from the controller
            if (caoCtrl != null)
            {
                CaoControllers ctrls = caoWs.Controllers;
                ctrls.Remove(caoCtrl.Name);

                Marshal.ReleaseComObject(caoCtrl);
                caoCtrl = null;

                Marshal.ReleaseComObject(ctrls);
                ctrls = null;
            }

            // Disable command buttons
            cmdConnectScanner.Enabled = true;
            cmdDisconnectScanner.Enabled = false;
            cmbMode.Enabled = true;
            numudCom.Enabled = true;
            btnRead.Enabled = false;
        }

        // OnMessage event
        private void OnMessage(CaoMessage pICaoMsg)
        {
            try
            {
                SetTextCallback SetMsg = new SetTextCallback(SetText);
                Invoke(SetMsg, pICaoMsg.Value.ToString());
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }

        private void SetText(string msg)
        {
            lblDsp.Text += msg;
        }
  
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            cmdDisconnectScanner_Click(sender, e);

            // Delete CaoEngine
            if (caoWs != null)
            {                
                Marshal.ReleaseComObject(caoWs);
                caoWs = null;
            }

            if (caoWss != null)
            {                
                Marshal.ReleaseComObject(caoWss);
                caoWss = null;
            }

            if (caoEng != null)
            {               
                Marshal.ReleaseComObject(caoEng);
                caoEng = null;
            }
        }

        private void btnClear_Click(object sender, EventArgs e)
        {
            lblDsp.Clear();
        }

        private void btnRead_Click(object sender, EventArgs e)
        {
            try
            {
                lblDsp.Text += caoVar.Value.ToString();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
    }
}