MenuTracker.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / UIAutomation / UIAutomationClient / MS / Internal / Automation / MenuTracker.cs / 1305600 / MenuTracker.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// 
// Description: Class used to track context menus appearing 

// 
// History:
//  3/23/2004 : preid Created
//
//--------------------------------------------------------------------------- 

using System; 
using System.Text; 
using System.Windows.Automation;
using System.Diagnostics; 
using MS.Win32;

namespace MS.Internal.Automation
{ 
    internal delegate void MenuHandler( AutomationElement rawEl, bool menuHasOpened );
 
    // MenuOpened - Class used to track context menus appearing 
    internal class MenuTracker : WinEventWrap
    { 
        //-----------------------------------------------------
        //
        //  Constructors
        // 
        //-----------------------------------------------------
 
        #region Constructors 

        internal MenuTracker(MenuHandler newHandler) 
            : base(new int[] {NativeMethods.EVENT_SYSTEM_MENUPOPUPSTART, NativeMethods.EVENT_SYSTEM_MENUPOPUPEND})
        {
            AddCallback(newHandler);
        } 

        #endregion Constructors 
 

        //------------------------------------------------------ 
        //
        //  Internal Methods
        //
        //----------------------------------------------------- 

        #region Internal Methods 
 
        internal override void WinEventProc(int eventId, IntPtr hwnd, int idObject, int idChild, uint eventTime)
        { 
            AutomationElement rawEl = null;
            bool menuHasOpened = eventId == NativeMethods.EVENT_SYSTEM_MENUPOPUPSTART;

            // Only create a raw element wrapper if the menu has popped up.  Send a 
            // null element for menu closed (the element isn't available anymore).
            // 
 

            if( menuHasOpened ) 
            {
                // Ignore if this is a bogus hwnd (shouldn't happen)
                if( hwnd == IntPtr.Zero )
                    return; 

                NativeMethods.HWND nativeHwnd = NativeMethods.HWND.Cast( hwnd ); 
                if( !SafeNativeMethods.IsWindow( nativeHwnd ) ) 
                    return;
 
                // Filter... send events for visible hwnds only
                if( !SafeNativeMethods.IsWindowVisible( nativeHwnd ) )
                    return;
 
                rawEl = AutomationElement.FromHandle( hwnd );
            } 
 
            // Do callback.  This handler is called due to a WinEvent on the client.  The handler
            // is going to hand off the work of calling out to the client code to another thread 
            // via a queue so it is safe to do this callback w/in the lock.
            object [] handlers = GetHandlers();
            Debug.Assert(handlers.Length <= 1, "handlers.Length");
            if( handlers.Length > 0 ) 
                ( ( MenuHandler )handlers[0] )( rawEl, menuHasOpened );
        } 
 
        #endregion Internal Methods
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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