htmlのinputとtextareaをクリックした際に、Windowsフォームを表示する。

ここではかなウェルというブラウザを例にしています。
かなウェル->　http://lsl.way-nifty.com/kanawel/

ブラウザコンポーネント：MyTabWebBrowser.cs

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

namespace ABCS.Classes
{
    public class MyTabWebBrowser : WebBrowserEx
    {
        protected bool isDocumentComplete_ = false;
        protected TabPage tab_ = null;
        protected int titleMaxLength_ = 5;
        protected Form parentForm_ = null;
        protected string title_ = "";
        protected string beforeurl_ = null;
        protected TabControl parentTabControl_ = null;
        protected Panel parentPanel_ = null;
        protected frm50 frm50_ = null;

        public string SiteTitle
        {
            get
            {
                return this.title_;
            }
        }

        public void SetTitle2Form()
        {
            this.parentForm_.Text = this.title_;
        }


        public bool IsDocumentCompleted
        {
            get
            {
                return this.isDocumentComplete_;
            }
        }
        public MyTabWebBrowser(Form parentForm, TabControl parentTabControl ,TabPage tab, int titleMaxLength, frm50 Frm50, Panel parentPanel)
            : base()
        {
            this.frm50_ = Frm50;
            this.parentPanel_ = parentPanel;
            //this.DocumentCompleted += this.evDocumentCompleted;
            this.parentTabControl_ = parentTabControl;
            this.tab_ = tab;
            this.titleMaxLength_ = titleMaxLength;
            this.parentForm_ = parentForm;
            this.NewWindow2 += new WebBrowserNewWindow2EventHandler(webBrowser_NewWindow2);
            this.BeforeNewWindow += new EventHandler(OnMyBeforeNewWindow);

        }
        protected override void OnDocumentCompleted(WebBrowserDocumentCompletedEventArgs e)
        {
            base.OnDocumentCompleted(e);
            isDocumentComplete_ = true;

            this.title_ = this.DocumentTitle.Trim();

            this.parentForm_.Text = this.title_;
            this.tab_.Text = this.title_.Substring(0,(this.titleMaxLength_< this.title_.Length ) ? this.titleMaxLength_ : this.title_.Length);

            this.ChainOnDocumentCompleted(e);
        }

        protected override void OnNavigating(WebBrowserNavigatingEventArgs e)
        {
            base.OnNavigating(e);
            isDocumentComplete_ = false;
        }

        protected void OnMyBeforeNewWindow(object sender, EventArgs e)
        {
            WebBrowserExtendedNavigatingEventArgs we = e as WebBrowserExtendedNavigatingEventArgs;
            if (we != null)
            {
                this.beforeurl_ = we.Url;
            }
        }

        // 新しくウィンドウを開かれようとするときに発生する
        void webBrowser_NewWindow2(object sender, WebBrowserNewWindow2EventArgs e)
        {
            MyTabPageWithWeb tab = new MyTabPageWithWeb(this.parentForm_,this.parentTabControl_, this.parentPanel_,this.beforeurl_, this.frm50_);


            // 新しい WebBrowser の初期化
            //WebBrowserEx newBrowser = new WebBrowserEx();
            //newBrowser.Dock = DockStyle.Fill;

            // 新しい WebBrowser のコンテナ（下記はタブの場合）
            //var tabPage = new TabPage();
            //tab.Controls.Add(newBrowser);
            this.parentTabControl_.TabPages.Add(tab);

            // 新しい WebBrowser に表示させる設定
            //e.ppDisp = newBrowser.Application;
            //newBrowser.RegisterAsBrowser = true;
            e.ppDisp = tab.ChildWebBrowser.Application;
            tab.ChildWebBrowser.RegisterAsBrowser = true;

            // 新しい WebBrowser からさらにウィンドウを開かれるときも同じようにする
            //newBrowser.NewWindow2 += webBrowser_NewWindow2;
            tab.ChildWebBrowser.NewWindow2 += webBrowser_NewWindow2;

            //newBrowser.Navigate(this.beforeurl_);
            //tab.ChildWebBrowser.Navigate(this.beforeurl_);

            this.parentTabControl_.SelectTab(tab);

            e.Cancel = true;
        }


        #region ソフトキーボード機能
        /// 
Clickイベントを処理するメソッドを表します。
        public delegate void MyHtmlElementEventHandler(object sender, MyHtmlElementEventArgs e);
        
        [Category("アクション"), Description("クリックした時に発生します。")]
        public event MyHtmlElementEventHandler MyCustomClick;

        //#region//Tabマウスイベント
        void MyTabWebBrowser_MyCustomClick(object sender, System.Windows.Forms.HtmlElementEventArgs e)
        {
            try
            {
                MyHtmlElementEventArgs E = new MyHtmlElementEventArgs(e, this);
                this.MyCustomClick(sender, E);
            }
            catch (NullReferenceException) { }
        }



        protected void ChainOnDocumentCompleted(WebBrowserDocumentCompletedEventArgs e)
        {
            //base.OnDocumentCompleted(e);

            HtmlElementCollection ecol = this.Document.Body.GetElementsByTagName("input");
            foreach (HtmlElement el in ecol)
            {
                if (el.GetAttribute("type").ToString().ToLower() == "text"
                    || el.GetAttribute("type").ToString().ToLower() == "password")
                {
                    el.Click += new HtmlElementEventHandler(MyTabWebBrowser_MyCustomClick);
                }

            }
            HtmlElementCollection ecol2 = this.Document.Body.GetElementsByTagName("textarea");
            foreach (HtmlElement el in ecol2)
            {
                el.Click += new HtmlElementEventHandler(MyTabWebBrowser_MyCustomClick);
            }

        }


        public int CurPosX = 0;
        public int CurPosY = 0;


        public void setCurPos()
        {
            // ブラウザ上のマウスの位置を取得
            Point p = new Point();

            p = this.PointToClient(MousePosition);

            this.CurPosX = p.X;
            this.CurPosY = p.Y;


            // 複数のWebBrowserで共有するなら・・・
            // ((WebBroser)sender).PointToClient(MousePosition);
            // マウスの位置にあるエレメントを取得
            //this.Document.GetElementFromPoint(p);

        }

        #endregion
    }

    /// 
TabMouseClickイベントのデータ
    public class MyHtmlElementEventArgs 
    {
        private MyTabWebBrowser web_ = null;
        private System.Windows.Forms.HtmlElementEventArgs e_ = null;
        /// クリックされたタブに対応したタブのインデックス
        public MyHtmlElementEventArgs(System.Windows.Forms.HtmlElementEventArgs e, MyTabWebBrowser web)
        {
            this.e_ = e;
            this.web_ = web;
        }
        /// 
クリックされたタブに対応したタブページ
        public MyTabWebBrowser MyWeb
        {
            get
            {
                return this.web_;
            }
        }
        public System.Windows.Forms.HtmlElementEventArgs E
        {
            get
            {
                return this.e_;
            }
        }
    }

}

クリックイベントを実装するクラス：TabPageの派生
void softkbd_clickがイベントハンドラ

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using ABCS.Interfaces;
using ABCS.Forms;

namespace ABCS.Classes
{
    public class MyTabPageWithWeb : TabPage
    {
        private MyTabWebBrowser web_ = null;
        private MyTabControlWidthRadio childTabControl_ = null;
        private TabControl ParentTabControl_ = null;
        private Panel ParentPanel_ = null;
        private frm50 Frm50_ = null;
        private Form parentForm_ = null;

        public MyTabWebBrowser ChildWebBrowser
        {
            get
            {
                return this.web_;
            }

        }

        public MyTabControlWidthRadio ChildTabControlWithRadio
        {
            get
            {
                return this.childTabControl_;
            }
        }

        public MyTabPageWithWeb(Form parentForm, TabControl parentTabControl_, Panel parentPanel,string url, frm50 Frm50)
            : base()
        {
            this.Frm50_ = Frm50;
            this.parentForm_ = parentForm;
            this.ParentTabControl_ = parentTabControl_;
            this.ParentPanel_ = parentPanel;
            //this.AllowDrop = true;
            this.web_ = new MyTabWebBrowser(parentForm, parentTabControl_, this, 10, this.Frm50_,this.ParentPanel_);
            this.web_.MyCustomClick += this.softkbd_click;

            //this.childTabControl_ = new MyTabControlWidthRadio();


            /* //?Dock は後続の方が優先される（スタック形式？）
            ctabctrl.Dock = DockStyle.Top;
            tab.Controls.Add(ctabctrl);
            */

            //Web表示
            this.web_.Dock = DockStyle.Fill;
            this.Controls.Add(this.web_);

            // //?Dock は後続の方が優先される（スタック形式？）
            // //そのため、ctabctrlのaddをwebのaddより後方に移した。
            // //（?を?に移した）
            //this.childTabControl_.Dock = DockStyle.Top;
            //this.Controls.Add(this.childTabControl_);

            //web.DocumentCompleted += webDocumentCompleted;

            this.web_.Navigate(url);

        }

        private void softkbd_click(object sender, MyHtmlElementEventArgs e)
        {
            //MessageBox.Show("focus");
            HtmlElement el = sender as HtmlElement;
            if (el == null) return;

            MyTabWebBrowser web = e.MyWeb;

            web.setCurPos();

            int x = web.CurPosX;
            int y = web.CurPosY;

            //MessageBox.Show("x=" + x + ",y=" + y);

            if ( ( this.Frm50_.Height < web.Height)
                && (y + this.Frm50_.Height > web.Height) )
            {
                y = y - this.Frm50_.Height - 72;
                if (y < 0) y = 0;
            }
            if (x + this.Frm50_.Width > this.ParentPanel_.Width)
            {
                x = this.ParentPanel_.Width - this.Frm50_.Width;
            }

            int top = this.parentForm_.Top + this.ParentPanel_.Top+ y + 72;
            int left = this.parentForm_.Left+ this.ParentPanel_.Location.X + x;


            this.Frm50_.origText = el.InnerText;
            this.Frm50_.Top = top;
            this.Frm50_.Left = left;
            this.Frm50_.htmlElement = el;
            this.Frm50_.Show();
            this.Frm50_.Focus();

        }

    }
}