Updated form selector to allow selection of existing forms

InsertFormWizard.cs

using System;
using System.Text;
using Sitecore;
using Sitecore.Data.Items;
using Sitecore.Globalization;
using Sitecore.Web.UI.HtmlControls;
using Sitecore.Web.UI.Sheer;

namespace Sitecore.Custom.WFFM.UI
{
    public class InsertFormWizard : Sitecore.Forms.Shell.UI.InsertFormWizard
    {
        protected Radiobutton ChooseExistingForm;

        protected override void Localize()
        {
            base.Localize();
            this.ChooseExistingForm.Header = "Select an existing form";
        }

        protected override bool ActivePageChanging(string page, ref string newpage)
        {
            if (newpage == "SelectPlaceholder" && page == "SelectForm" && this.ChooseExistingForm.Checked)
                newpage = string.IsNullOrEmpty(base.Placeholder) ? "SelectPlaceholder" : "ConfirmationPage";

            if (this.ChooseExistingForm.Checked && newpage == "AnalyticsPage")
                newpage = "ConfirmationPage";

            bool flag = base.ActivePageChanging(page, ref newpage);
            if (newpage == "ConfirmationPage" && this.ChooseExistingForm.Checked)
            {
                base.ChoicesLiteral.Text = RenderFormSelection();
            }
            return flag;
        }

        private string RenderFormSelection()
        {
            Item source = ExistingFormSelection();

            StringBuilder stringBuilder = new StringBuilder();
            stringBuilder.Append("<fieldset class='scfGroupSection' >");
            stringBuilder.Append("<legend>FORM</legend>");
            stringBuilder.Append("<p>Using existing form: " + source.Paths.FullPath + "</p>");
            return stringBuilder.ToString();
        }

        protected override void ActivePageChanged(string page, string oldPage)
        {
            base.ActivePageChanged(page, oldPage);
            if (page == "ConfirmationPage" && this.ChooseExistingForm.Checked)
            {
                this.NextButton.Header = "Confirm";
            }
        }

        protected override void OnNext(object sender, EventArgs formEventArgs)
        {
            if (this.NextButton.Header == "Confirm" && this.ChooseExistingForm.Checked)
            {
                this.SaveExistingFormSelection();
                SheerResponse.SetModified(false);
                this.Next();
                return;
            }
            base.OnNext(sender, formEventArgs);
        }

        private void SaveExistingFormSelection()
        {
            Item source = ExistingFormSelection();
            this.ServerProperties[this.newFormUri] = source.Uri.ToString();
            Registry.SetString("/Current_User/Dialogs//sitecore/shell/default.aspx?xmlcontrol=Forms.FormDesigner", "1250,500");
            SheerResponse.SetDialogValue(source.ID.ToString());
        }

        private Item ExistingFormSelection()
        {
            string queryString = Sitecore.Web.WebUtil.GetQueryString("la");
            Language result = Context.ContentLanguage;
            if (!string.IsNullOrEmpty(queryString))
                Language.TryParse(Sitecore.Web.WebUtil.GetQueryString("la"), out result);

            Item source = this.FormsRoot.Database.GetItem(this.multiTree.Selected, result);
            return source;
        }
    }
}

InsertFormWizard.xml

<?xml version="1.0" encoding="utf-8" ?>
<control xmlns:def="Definition" xmlns="http://schemas.sitecore.net/Visual-Studio-Intellisense">
  <Forms.InsertFormWizard>

    <Stylesheet runat="server" Src="MultiTreeView.css" DeviceDependant="true"/>
    <Stylesheet runat="server" Src="Content Manager.css" DeviceDependant="true"/>
    <Stylesheet runat="server" Src="default.css" DeviceDependant="true"/>
    <Stylesheet runat="server" Src="/webedit.css" DeviceDependant="true"/>

    <Stylesheet Key="SelectFields">

      .scPalettePlaceholderSelected,
      .scPalettePlaceholder
      {
      width:100%;
      }

    </Stylesheet>

    <Script runat="server" Src="/sitecore/shell/controls/lib/jquery/jquery.js"/>

    <Script type="text/javascript" runat="server">
      var $j = jQuery.noConflict();
    </Script>

    <Script runat="server" Src="/sitecore/shell/Applications/Modules/Web Forms for Marketers/script/jquery.numeric.pack.js"/>

    <Script runat="server" Src="/sitecore/shell/controls/SitecoreObjects.js"/>
    
    <Script runat="server" Src="/sitecore/shell/controls/SitecoreVSplitter.js"/>
    <Script runat="server" Src="/sitecore/shell/controls/SitecoreWindow.js"/>
    <Script runat="server" Src="/sitecore/shell/controls/SitecoreKeyboard.js"/>

    <WizardForm Application="Modules/Web Forms for Marketers/Insert Form Wizard" 
                CodeBeside="Sitecore.Custom.WFFM.UI.InsertFormWizard, Sitecore.Custom">

      <Script runat="server" Src="/sitecore/shell/Applications/Modules/Web Forms for Marketers/script/Utils.js"/>
      <Script runat="server" Src="/sitecore/shell/Applications/Modules/Web Forms for Marketers/script/Sitecore.PlaceholderManager.js"/>


      <WizardFormPage ID="CreateForm" Icon="Applications/32x32/form_green_add.png" >
        <Groupbox  Width="100%" Height="100%"  Cellpadding="2" Style="table-layout:fixed;border:0px;width: auto !important;" Margin="10px 10px 10px 10px" >
          <Border ColCount="2"  Width="100%" Cellpadding="0" Margin="10px 10px 10px 10px">
            <Literal ID="FormNameLiteral" Margin="5px 5px 5px 5px"/>
            <Edit ID="EbFormName" Width="80%"  Margin="0px 0px 0px 0px"/>
          </Border>
          <Border Margin="10px">
            <Radiobutton ID="CreateBlankForm" Name="ChooseOperation" Value="no"/>
          </Border>
          <Border Margin="10px">
            <Radiobutton ID="ChooseForm" Name="ChooseOperation" Value="yes" />
          </Border>
          <Border Margin="10px">
            <Radiobutton ID="ChooseExistingForm" Name="ChooseOperation" Value="existing" />
          </Border>
        </Groupbox>
        <script type="text/javascript" runat="server">
          $j('input[name="ChooseOperation"]').change(function() {
            if (this.value == "existing") {
              $j("#EbFormName").attr("disabled", "disabled");
            } else {
              $j("#EbFormName").removeAttr("disabled");
            }
          });
        </script>
      </WizardFormPage>

      <WizardFormPage ID="SelectForm" Icon="Applications/32x32/form_green_add.png" >
        <GridPanel Width="100%" Cellpadding="0" Style="table-layout:fixed" Padding="10px">
          <Scrollbox ID="ExistingForms" Width="96%" Position="absolute" Valign="top" Padding="10px 1px 10px 10px"  style="overflow:auto;height:455px"/>
        </GridPanel>
      </WizardFormPage>

      <WizardFormPage ID="SelectPlaceholder" Icon="Applications/32x32/form_green_add.png">
        <Forms.PlaceholderList ID="Placeholders" />
      </WizardFormPage>

      <WizardFormPage ID="AnalyticsPage" Icon="Business/32x32/chart.png">

        <Border Padding="10px">
          <GridPanel Cellpadding="0" Style="table-layout:fixed" >                    
            <Groupbox ID="AnalyticsOptions" Width="100%" Height="100%"  Cellpadding="0" Style="table-layout:fixed;border-left:0px;border-right:0px;border-bottom:0px" Margin="0px 10px 0px 10px" >
              <Border Padding="0px 0px 0px 20px" Margin="10px 0px 0px 0px">
                <Radiobutton ID="CreateGoal" Name="GoalOperation" Value="yes" Click="form:creategoal"/>
                <Border Padding="3px 0px 5px 2px">
                  <GridPanel Columns="2" Cellpadding="0"  Padding="0px 0px 0px 20px" Margin="0px">
                    <Literal ID="GoalNameLiteral" GridPanel.Height="15px" />
                    <Literal ID="PointsLiteral" GridPanel.Height="15px"  GridPanel.Width="35%" Margin="0px 0px 0px 10px"/>
                    <Edit ID="GoalName" Width="100%"/>
                    <Edit ID="Points" Class="Range" Margin="0px 0px 0px 10px" Value="0"  Width="70%"/>
                  </GridPanel>

                  <script type="text/javascript" runat="server">                    
                      $j(".Range").numeric();                    
                  </script>
                  
                </Border>
              </Border>
              <Border GridPanel.vAlign="top" Height="100%" Padding="0px 0px 0px 20px" Margin="0px 0px 10px 0px">
                <Radiobutton ID="SelectGoal" Name="GoalOperation" Value="no" Click="form:creategoal"/>
                <DataContext ID="GoalsDataContext" DataViewName="Master" ShowRoot="false" Root="{0CB97A9F-CAFB-42A0-8BE1-89AB9AE32BD9}" Filter="Contains('{059CFBDF-49FC-4F14-A4E5-B63E1E1AFB1E},{475E9026-333F-432D-A4DC-52E03B75CB6B}, {A87A00B1-E6DB-45AB-8B54-636FEC3B5523}, {DB6E13B8-786C-4DD6-ACF2-3E5E6A959905}', @@templateid)" DefaultItem="{0CB97A9F-CAFB-42A0-8BE1-89AB9AE32BD9}"/>
                <TreePickerEx ID="Goals" DataContext="GoalsDataContext" SelectOnly="true" AllowNone="false" Width="90%"/>
                <script type="text/javascript" language="javascript">
                  $$('#Goals')[0].setAttribute("disabled", "1");
                  $$('.scComboboxDropDown')[0].disabled = true;
                </script>
              </Border>
              <Border Padding="0px 10px 0px 10px" Margin="0px 0px 0px 10px" Style="color:#999999">
                <Literal ID="SelectGoalLiteral"/>
              </Border>
            </Groupbox>
            <Groupbox ID="DropoutOptions" Width="100%" Height="100%"  Cellpadding="0" Style="table-layout:fixed;border-left:0px;border-right:0px;border-bottom:0px" Margin="10px" >
              <Checkbox Margin="0px 3px 0px 20px" ID="EnableFormDropoutTracking" Click="form:trackingenable"  style="margin-top:10px"/>
              <Border Padding="10px 3px 0px 20px" Style="color:#999999">
                <Literal ID="EnableFormDropoutTrackingLiteral" />
                <br/>
                <Literal ID="EnableDropoutSavedToLiteral"/>
              </Border>
            </Groupbox>
          </GridPanel>
        </Border>
      </WizardFormPage>


      <WizardFormPage ID="ConfirmationPage" Icon="Applications/32x32/form_green_add.png" >
        <Scrollbox Border="none" Background="transparent" Height="100%" Padding="10px" style="overflow-x:hidden">
          <Border ID="ChoicesPanel" Height="90%"  Margin="0px 0px 16px 0px" >
            <Border  class="scWfmConfirmText" Padding="0px 10px 10px 10px" ID="ChoicesPane" >
              <Literal ID="ChoicesLiteral"/>
            </Border>
          </Border>
        </Scrollbox>
      </WizardFormPage>

    </WizardForm>
  </Forms.InsertFormWizard>
</control>