Citrix states in their article: CTX101644

CTX101644 - Seamless Exception Registry Flags

This document was published at: http://support.citrix.com/article/CTX101644

Document ID: CTX101644, Created on: Mar 17, 2003, Updated: May 1, 2006

Products: Citrix MetaFrame XP 1.0 for Microsoft Windows 2000, Citrix Presentation Server 4.0 for Microsoft Windows 2000, Citrix Presentation Server 4.0 for Microsoft Windows 2003, Citrix MetaFrame XP 1.0 for Microsoft Windows 2003, Citrix MetaFrame Presentation Server 3.0 for Microsoft Windows 2000, Citrix MetaFrame Presentation Server 3.0 for Microsoft Windows 2003, ICA Win32 Program Neighborhood Client, ICA Win32 Web Client, ICA Win32 Program Neighborhood Agent

Symptoms

This document outlines the currently available Server Seamless Engine Exception Registry Flags that can be used to control specific behavior of an Application's Windows when run in an ICA Seamless Session. There are two sections, Global and per Specified Window. The contents of this document are subject to change at any time.

Global Registry Flags

NOTE: These values affect all Seamless connections to a Server and require changing the value of only one specific Registry key. If more than one of these flags are needed, then add them together as follows.

For example to use Flags 1 and 8 below, the value for SeamlessFlags would be 0x1 + 0x200 = 0x201.

Or if you wanted to use Flags 1, 8 and 9 then the value for SeamlessFlags would be 0x1+0x200+0x400 = 0x601.

Remember that these values are in the Hex format. Look at the following example:

0x20 + 0x80 = 0xA0

Registry Key: HKLM/System/CurrentControlSet/Control/Citrix/wfshell/TWI
Value Name: SeamlessFlags
Value Type: REG_DWORD
Values: See 1 through 15 Below

1. DISABLE SESSION SHARING

Value: 0x1

Explanation: Determines if each Seamless connection to the server uses Session Sharing. Use this Flag to Disable Session Sharing. Without this Registry Value set, or setting this value to 0x0 enables Session Sharing.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3 - MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

2. DISABLE MODALITY CHECK

Value: 0x2

Explanation: Specifies that the ICA client will not perform a Modality check. The owner window of a Modal Dialog can be moved, although input focus will remain on the Modal Dialog. This is useful when running an application such as PaintShop Pro Version 6 in a Seamless session. Without this Registry Value set, or setting this value to 0x0 specifies that the ICA client will perform a Modality check on Seamless windows.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

3. DISABLE ACTIVE ACCESSIBILITY HOOK

Value: 0x4

Explanation: Determines if the Seamless Engine will load its Active Accessibility hook in a Seamless session. By default the Seamless Engine uses a technique called event hooking to monitor any changes made to an application’s windows on the server and sends these changes to the ICA Client. Wfshell.exe loads the DLL, sehook20.dll. Without this Registry Value set, or setting this value to 0x0 specifies that Active Accessibility is enabled.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k, or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

4. ENABLE COLOR SYNC

Value: 0x10

Explanation: Specifies that the Seamless session will inherit the client system color settings. This may cause problems with some applications when the color scheme used on the client is not fully supported by the server. Without this Registry Value set, or setting this value to 0x0 specifies that the Seamless session will not inherit the client system color settings.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

5. DISABLE SYSTRAY AGENT

Value: 0x20

Explanation: Specifies that the System Tray agent in a Seamless session will not be created. The System Tray agent allows an application that uses the System Tray, using the Shell_NotifyIcon API, to be sent to the ICA client’s System Tray. Without this Registry Value set, or setting this value to 0x0 specifies that System Tray agent in a Seamless session will be created.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

6. DISABLE ICONIC WINDOWS

Value: 0x80

Explanation: Specifies that iconic windows will not be sent to the ICA client. This may improve performance slightly, however setting it can cause problems with applications such as MS Office when run in a Seamless session. For example, the application’s icon may not be visible when it is minimized on the local Client Taskbar. Without this Registry Value set, or setting this value to 0x0, specifies that iconic windows are sent to the ICA client.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

7. DISABLE LOAD CHECK

Value: 0x100

Explanation: By default Load Balancing takes precedence over Session Sharing on a fully loaded server. New connections are routed to other less busy servers, rather than have their sessions shared with existing connections. Setting this Flag along with the required updates listed below, will allow session sharing of connections on fully loaded servers. Without this Registry Value set, or setting this value to 0x0, will retain the default Load Balancing behavior.

Required: XE104W2K3R02 or XE104W2KR02 for MF XP 1.0. MPSE300R04W2k3016 or MPSE300R04W2K016 for MPS 3.0.

8. DISABLE WM_QUERYDRAGICON MESSAGES

Value: 0x200

Explanation: Specifies that the Seamless engine will not send WM_QUERYDRAGICON messages to application windows to obtain the Icons associated with them. Without this Registry Value set, or setting this value to 0x0, the Seamless engine will send these messages to application windows to get the Icons associated with them.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3..

9. FORCE RAW MOUSE EVENTS TO SERVER

Value: 0x400

Explanation: Specifies that the ICA client will send raw mouse event messages to the server. This is useful, when running an application developed using the Borland IDE, which allows the creation of dialog boxes that behave like a modal dialog box, but its parent window still responds to certain types of window messages, like WM_SETFOCUS. Without this Registry Value
set, or setting this value to 0x0, specifies that the ICA client will send regular translated mouse event messages to the server.

Required: ICA Win32 Client version 6.31 or later - MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3, MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

10. DISABLE FULL WINDOW DRAG

Value: 0x800

Explanation: Specifies that the Windows feature "Full Window Drag" can be disabled. This may be necessary for some non-standard applications. Without this Registry Value set, or setting this value to 0x0 specifies this Windows feature is enabled.

Required: MF XP 1.0 SP3 for Win2k or Win2k3, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

11. FORCE MENU WINDOW TO HAVE OWNER

Value: 0x1000

Explanation: Specifies that Menu Windows will always be re-created on the ICA client with an owner window.

Required: International versions of MF XP SP3 for Win2k or Win2k3, Post MF XP SP3 English Hotfix XE103W2K126 for Win2k or later, post MF XP SP3 English Hotfix XE103W2K3037 for Win2k3 or later, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

12. DISABLE SHELL HOOK AGENT

Value: 0x2000

Explanation: Instant Messenger type programs commonly use the FlashWindow() API to flash the taskbar button to alert users of incoming messages. After applying the updates listed below in the 'Required' section, support for the FlashWindow() API is added and turned on by default.

Setting the Global Seamless registry value (0x2000) disables this default behavior.

Required: Post MF XP SP3 English Hotfix XE103W2K126 for Win2k or later, post MF XP SP3 English Hotfix XE103W2K3037 for Win2k3 or later, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

13. DISABLE CLIENT INFO SYNC

Value: 0x4000

Explanation: Some custom applications that did not display properly when running on Windows XP/2000 with the Windows XP Theme enabled, sometimes experienced the same behavior when running as a seamless application on MetaFrame XP Feature Release 3 on Windows 2003 that does not have the Windows XP Theme enabled. For example, the title bar of the application is larger in height.

Starting with MetaFrame XP Feature Release 3 for Windows 2000/2003, the server seamless engine has extended support for certain window style properties of the workstation where the seamless application is running; for example, the styles generated by Windows XP Themes.

This new seamless global registry flag, when set, instructs the server-side seamless engine not to read certain client workstation window style information.

Set the following server-side registry key to instruct the server seamless engine not to synchronize with the client's window style that pertains to those representative of the Windows XP Theme:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI

Name: SeamlessFlags
Type: REG_DWORD
Value: 0x4000

Custom applications that do not display properly when running on Windows XP/2000 with the Windows XP Theme enabled can be run in a seamless session from a workstation that has the Windows XP Theme enabled and be displayed using the Windows Classic style.

Additionally, when setting this Flag, extended data about the client side Desktop is not used in a Seamless session, including the size of the local Desktop Work Area. As a result, when minimizing some applications run in a Seamless session, they may minimize to the local Desktop above the Taskbar or overlap it. The reason for this, is that the size and position of the Local Taskbar is not being sent to the Server session, therefore, these metrics are not being used when the calculations are made on where on the Desktop the application is to be minimized to.

Required: Post MF XP SP3 English Hotfix XE103W2K126 for Win2k or later, post MF XP SP3 English Hotfix XE103W2K3037 for Win2k3 or later. MPSE300W2KR04 or MPSE300W2K3R04 for MPS 3.0. Included in base CPS 4.0.

14. TWI_FLAGS_DONT_SEND_DISABLE

Value: 0x8000

Explanation: Setting this Flag reverses the behavior introduced in version 8.0 of the Win32 ICA client for Seamless connections of sending the WS_DISABLED Window Style to the client. Supporting this Window Style would cause a small number of custom applications to lose focus to a local application window running on the workstation when the Seamless Application would set this Window Style and also have an invisible window in the background. The reason for introducing the ability to send the WS_DISABLE window style to the client was to support the implementation of Seamless application windows responding to the “Minimize All” or “Show Desktop” feature on Windows workstations. Therefore, setting this Flag has an affect on how Seamless Windows will respond to the windows messages sent by using the “Minimize All” or “Show Desktop” feature.

Support for this Seamless Flag can only be activated by applying both a Win32 client and Server update that support it. Please see the following requirements.

Required: Win32 client version 9.100 and later. For MF XP 1.0 - XE104W2KR01.MSP or XE104W2K3R01.MSP. MPSE300W2KR04 or MPSE300W2K3R04 for MPS 3.0. PSE400W2K3R01 or PSE400W2KR01 for CPS 4.0.

15. DO NOT SEND OFF SCREEN WINDOWS

Value: 0x20000

Explanation: Starting with CPS 4.0, windows that are created outside of the visible client desktop area are sent to the client. Set this Flag for custom applications that experience focus or Z-Order related issues when running them in a Seamless session.

Required: This Flag only applies to CPS 4.0 or later. Post CPS 4.0 HRP01 Hotfix PSE400R01W2k3053 or PSE400R01W2k035.

16. Job Object

Explanation: If a published application was a program that created a new process and then terminated itself, the published application appeared in the Management Console for MetaFrame XP. However, in a seamless session the application was launched through session sharing, the application appeared in the Management Console but then disappeared.

By default, the thread that checks the process cares about only the first instance of the launched process. The thread regarded the published application as terminated when the first instance of the process was terminated even if that process created a separate process.

This update provides a way to configure those published applications to use the JOB object so that additional processes created by the initial process are considered as published applications.

For this update to work properly, you need to perform the following steps:

If the command line of the published application is [ApplicationPath], go to the following registry key and make changes as necessary:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI\StartInJobObject
Key Value: [ApplicationPath]
Type: DWORD
Value: 0

For example, if the command line specified for the published application is c:\notepad.cmd, go to the following registry key and make changes as necessary:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI\StartInJobObject
Key Value: c:\notepad.cmd
Type: DWORD
Value: 0

For those applications whose command line is specified in the StartInJobObject key, the published application will not disappear from the Management Console until all of the processes created by the process
are terminated.

Required: Post MF XP SP3 English Hotfix XE103W2K126 for Win2k or later, post MF XP SP3 English Hotfix XE103W2K3037 for Win2k3 or later, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

17. Worker Wait Interval

Explanation: This update addresses a custom application's performance when run seamlessly. Some applications appeared to be slower to respond when performing actions such as moving, resizing, or closing windows. This fix introduces two new registry settings that allow administrators to configure an explicit time interval for the seamless engine mechanism to monitor when changes take place in the seamless applications.

Create the following two registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI
Key: WorkerWaitInterval
Type: REG_DWORD
Value: (Values are between 5 – 500; the default is 50.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Citrix\wfshell\TWI
Key: WorkerFullCheckInterval
Type: REG_DWORD
Value: (Values are between 50 – 5000; the default is 500.)

For both values, a larger size slows responsiveness but improves scalability; a smaller size increases responsiveness but decreases scalability slightly. The level of scalability depends on several factors, such as hardware sizing, types of applications, network performance, and number of users.

Required: Post MF XP SP3 English Hotfix XE103W2K126 for Win2k or later, post MF XP SP3 English Hotfix XE103W2K3037 for Win2k3 or later, MPSE300W2KR04 or MPSE300W2K3R04 for MPS 3.0. Included in base CPS 4.0.

Registry Flags Per Specified Window

These flags are used to single out a specific Window of an Application that may need to be handled differently by the Seamless Engine. To determine the Class Name of a Window, use SPY ++ from Microsoft Visual Studio or a Third Party Tool.

Specifying a Seamless exception flag for a specific application window consists of creating a registry key that is the same name as the Window Class Name and adding two Value Names, Type and ClassName, each with their own value.

Registry Key: HKLM/System/CurrentControlSet/Control/Citrix/wfshell/TWI/
Value Name1: ClassName
Value Type1: REG_SZ
Value1:
Value Name1: Type
Value Type2: REG_DWORD
Value2: See 1 through 8 Below

Steps to Add Per Specified Window Exception Flags:

a) Run Regedit.

b) Go to HKLM/System/CurrentControlSet/Control/Citrix/wfshell/TWI.

c) Highlight the TWI Key, then from the Edit Menu select New, then Key.

d) Enter for the Key Name.

e) Highlight the newly created Subkey.

f) From the Edit Menu, select New, then String Value.

g) Enter ClassName for the Value Name.

h) Double-click on the Value Name, enter for the Value data.

i) Highlight in the left pane.

j) From the Edit Menu select New, then DWORD value.

k) Enter Type for the Value Name.

l) Double-click on the Value Name, enter for the Value data.

Adding Multiple Window Class Names under one Registry Setting

See CTX153088 - Seamless: Adding Multiple Window Class Names under one Registry Setting

Creating a .Reg File

If a registry flag needs to be created on many servers, then it might be worthwhile to create it first on one server, then export the registry key as a .Reg file which can then be easily executed on the other servers. To export a .Reg file, Select Export from the Regedit File menu.

Specifying more than one Exception Flag for a window.

If more than one of these flags are needed for a specific window, then add them together as follows.

For example to use Flags 1 and 2 below, add 0x8 + 0x10 = 0x18

1. WINDOW ALWAYS VISIBLE

Value: 0x8

Explanation: For performance reasons, invisible windows that are created are not re-created on the ICA client. Setting this flag for a specified window enables it to be re-created on the ICA client.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3 - MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

2. WINDOW SIZE AND LOCATION NOT CHECKED

Value: 0x10

Explanation: For performance reasons, windows that are created with a Zero window size or created outside of the Desktop area, are not re-created on the ICA client. Setting this flag for such a specified window enables it to be re-created on the ICA client.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3 - MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3..

3. USE OWNER WINDOW INSTEAD OF PARENT

Value: 0x20

Explanation: Enabling this flag specifies that the Owner window of the window specified will be determined by using the GW_OWNER parameter instead of the GWL_HWNDPARENT parameter. This may be necessary if some application windows do not use the same window as both the Parent and Owner window.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3- MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

4. USE GETPARENT API

Value: 0x40

Explanation: Setting this value to a window enables the Seamless engine to use the GetParent API to get the Owner of the specified window.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3 - MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

5. SET AS INDEPENDENT WINDOW

Value: 0x80

Explanation: Setting this value to a window enables the Seamless engine to send the specified window as an independent window (no parent, no owner).

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3 - MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

6. SEND NO ICON CHANGES

Value: 0x100

Explanation: Setting this value to a window enables the Seamless engine not to send WM_GETICON or WM_QUERYDRAGICON messages to the specified window. This may cause some applications to have a generic icon displayed on the Local ICA client Taskbar instead of its own.

Required: MF 1.8 SP4 for TSE - MF 1.8 SP4 for Win2K - MF XP 1.0 SP3 for Win2k or Win2k3 - MF XP 1.0 SP2 for TSE, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

7. DO NOT REQUEST SMALL ICON

Value: 0x200

Explanation: Setting this value to a window, will direct the Server Seamless Engine to not request the small Icon associated with that window. This may be needed for application windows that alternate between different Icons while running that are not displaying the different Icons when run Seamlessly.

Required: Post MF XP SP3 English Hotfix XE103W2K126 for Win2k or later, post MF XP SP3 English Hotfix XE103W2K3037 for Win2k3 or later, MPS 3.0/CPS 4.0 for Win2k and Win2k3.

8. DO NOT SEND SPECIFIED ZERO-SIZED WINDOW TO THE CLIENT

Value: 0x400

Explanation: Setting this value to a
window that is zero-sized(a window that has the coordinates 0,0), will direct the Server Seamless Engine to not send that window information to the client.

This setting may need to be used in the following scenario:

Sessions do not log off when a user closes all Published Applications in a session, one or more of which may be using zero-sized windows - even though all visible windows of the application(s) have been closed.

Required: MF XP 1.0 - XE104W2KR01, XE104W2K3R01 or later. MPS 3.0 - MPSE300W2KR04, MPSE300W2K3R04 or later. CPS 4.0 - PSE400W2KR01, PSE400W2K3R01 or later.

Adding Global Seamless Exception Flags Graphic

Adding Specific Window Seamless Exception Flags Graphic.