vbAccelerator - Contents of code file: ShAutoComplete\AutoCompleteTextBox.cs

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace vbAccelerator.Controls.TextBox
{
   /// <summary>
   /// Adds Shell File System and URL AutoCompletion facilities to 
   /// a text box
   /// </summary>
   public class AutoCompleteTextBox : System.Windows.Forms.TextBox 
   {
      #region Unmanaged Code
      [Flags]
      public enum SHAutoCompleteFlags : uint
      {   
         SHACF_DEFAULT = 0x0,                          // Currently
          (SHACF_FILESYSTEM | SHACF_URLALL)
         SHACF_FILESYSTEM = 0x1,                        // This includes the
          File System as well as the rest of the shell (Desktop\My
          Computer\Control Panel\)
         SHACF_URLHISTORY = 0x2,                        // URLs in the User's
          History
         SHACF_URLMRU = 0x4,                            // URLs in the User's
          Recently Used list.
         SHACF_USETAB = 0x8,                            // Use the tab to move
          thru the autocomplete possibilities instead of to the next
          dialog/window control.
         SHACF_URLALL = (SHACF_URLHISTORY | SHACF_URLMRU),
         SHACF_FILESYS_ONLY = 0x10,                     // This includes the
          File System
         SHACF_FILESYS_DIRS = 0x20,                     // Same as
          SHACF_FILESYS_ONLY except it only includes directories, UNC servers,
          and UNC server shares.
         SHACF_AUTOSUGGEST_FORCE_ON = 0x10000000,       // Ignore the registry
          default and force the feature on.
         SHACF_AUTOSUGGEST_FORCE_OFF = 0x20000000,      // Ignore the registry
          default and force the feature off.
         SHACF_AUTOAPPEND_FORCE_ON = 0x40000000,        // Ignore the registry
          default and force the feature on. (Also know as AutoComplete)
         SHACF_AUTOAPPEND_FORCE_OFF = 0x80000000       // Ignore the registry
          default and force the feature off. (Also know as AutoComplete)
      }
      
      [DllImport("shlwapi.dll")]
      private static extern int SHAutoComplete (
         IntPtr hwndEdit, 
         AutoCompleteTextBox.SHAutoCompleteFlags dwFlags );

      #endregion

      #region Member Variables
      private AutoCompleteTextBox.SHAutoCompleteFlags autoCompleteFlags = 
         SHAutoCompleteFlags.SHACF_FILESYS_ONLY;
      private bool flagsSet = false;
      private bool handleCreated = false;
      #endregion

      #region Implementation

      /// <summary>
      /// Gets/sets the flags controlling automcompletion for the 
      /// text box
      /// </summary>
      public AutoCompleteTextBox.SHAutoCompleteFlags AutoCompleteFlags
      {
         get
         {
            return this.autoCompleteFlags;
         }
         set
         {
            this.autoCompleteFlags = value;
            this.flagsSet = true;
            if (handleCreated)
            {
               SetAutoComplete();
            }
         }
      }

      protected override void OnHandleCreated ( System.EventArgs e )
      {
         // call this first as SHAutoComplete may not be supported
         // on the OS
         base.OnHandleCreated(e);
         // don't do anything if we're in design mode:
         if (!this.DesignMode)
         {
            // remember we've created the handle for any future 
            // get/ set
            handleCreated = true;

            // if we've provided some flags then start autocompletion:
            if (flagsSet)
            {
               SetAutoComplete();
            }
         }
      }

      private void SetAutoComplete()
      {
         SHAutoComplete(this.Handle, this.autoCompleteFlags);
      }

      /// <summary>
      ///  Constructs an auto-complete capable text box but
      ///  does not automatically start auto-completion.
      /// </summary>
      public AutoCompleteTextBox() : base()
      {
      }

      /// <summary>
      /// Constructs an auto-complete capable text box and
      /// starts auto-completion with the specified flags.
      /// </summary>
      /// <param name="autoCompleteFlags">Flags controlling
      /// auto-completion</param>
      public AutoCompleteTextBox(
         AutoCompleteTextBox.SHAutoCompleteFlags autoCompleteFlags
         ) : this()
      {
         // Handle will not be available at this point; we need
         // to wait for HandleCreated:
         this.autoCompleteFlags = autoCompleteFlags;
         this.flagsSet = true;
      }

      #endregion
   }
}