WindowHideOrCloseTracker.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 / WindowHideOrCloseTracker.cs / 1305600 / WindowHideOrCloseTracker.cs
                        

                        
                            //---------------------------------------------------------------------------- 
//
// 
//    Copyright (C) Microsoft Corporation.  All rights reserved.
//  
//
// 
// Description: Class used to track new UI appearing and make sure any events 
// are propogated to that new UI.
// 
// History:
//  11/20/2003 : Micw Created
//
//--------------------------------------------------------------------------- 

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

namespace MS.Internal.Automation
{ 
    // WindowHideOrCloseTracker - Class used to track new UI appearing and make sure any events
    // are propogated to that new UI. 
    internal delegate void WindowHideOrCloseHandler( IntPtr hwnd, AutomationElement rawEl, int[] runtimeId ); 

    // Class used to track new UI appearing and make sure any events 
    // are propogated to that new UI.
    internal class WindowHideOrCloseTracker : WinEventWrap
    {
        //----------------------------------------------------- 
        //
        //  Constructors 
        // 
        //-----------------------------------------------------
 
        #region Constructors

        internal WindowHideOrCloseTracker(WindowHideOrCloseHandler newUIHandler)
            : base(new int[] 
            {NativeMethods.EVENT_OBJECT_DESTROY, NativeMethods.EVENT_OBJECT_HIDE})
        { 
            AddCallback(newUIHandler); 
        }
 
        #endregion Constructors


        //------------------------------------------------------ 
        //
        //  Internal Methods 
        // 
        //-----------------------------------------------------
 
        #region Internal Methods

        internal override void WinEventProc(int eventId, IntPtr hwnd, int idObject, int idChild, uint eventTime)
        { 
            // ignore any event not pertaining directly to the window
            if (idObject != UnsafeNativeMethods.OBJID_WINDOW) 
                return; 

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

            NativeMethods.HWND nativeHwnd = NativeMethods.HWND.Cast( hwnd ); 

            // Purposefully including windows that have been destroyed (e.g. IsWindow will return 
            // false here for EVENT_OBJECT_DESTROY) because we need that notification. 
            if (eventId == NativeMethods.EVENT_OBJECT_HIDE && !SafeNativeMethods.IsWindow( nativeHwnd ))
            { 
                return;
            }

            int[] runtimeId; 
            AutomationElement rawEl;
 
            if (eventId == NativeMethods.EVENT_OBJECT_DESTROY) 
            {
                // If the window has been destroyed just report the RuntimeId with the event. 
                runtimeId = HwndProxyElementProvider.MakeRuntimeId( nativeHwnd );
                rawEl = null;
            }
            else 
            {
                // If the window is just being hidden then can create (and return as event src) a real element 
                rawEl = AutomationElement.FromHandle( hwnd ); 
                runtimeId = rawEl.GetRuntimeId();
            } 

            // Do the notify.  Note that this handler is used to notify client-side UIAutomation providers of windows
            // being destroyed or hidden.  The delegate called here is itself protected by a lock.  This delegate may
            // call out to proxies but also calls ClientEventManager.RaiseEventInThisClientOnly which properly 
            // queues the actual callout to client code.
            object[] handlers = GetHandlers(); 
            Debug.Assert(handlers.Length <= 1, "handlers.Length"); 
            if ( handlers.Length > 0 )
                ( (WindowHideOrCloseHandler)handlers [0] )( hwnd, rawEl, runtimeId ); 
        }

        #endregion Internal Methods
 

        //------------------------------------------------------ 
        // 
        //  Private Fields
        // 
        //------------------------------------------------------

        #region Private Fields
 
        // no state
 
        #endregion Private Fields 
    }
} 

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

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