Application Sharing

This feature makes it possible for you, as a conference participant, to permit other participants to see and even use applications running on your desktop. Any application, from a simple text editor to a spreadsheet or complex design package can be shared. Application sharing uses an open, international standard (ITU-T T.128), which means that, for example, SGImeeting can view and control applications shared by a system running Microsoft NetMeeting for Windows NT.

When one person in the conference decides to share an application, all the other users in the conference see that application window on their system as if it were running locally. The window is "tagged" with the name of the user who shared the application.

Note: remote users only see the portion of the application that is exposed on the hosting system's screen. Areas of the application windows that are obscured by applications that are note shared are displayed as a cross-hatch pattern.

Initially, only the person who shared the application can control it; everyone else can merely see the output in the shared window. If that person then clicks the Collaborate button, others are allowed to take control, although only one person can be in control at a time.

The T.128 application sharing protocol is limited to 8-bit application sharing, meaning that applications using more colors often need to be color reduced to 8-bit color (256 colors). This causes a reduction in color quality for shared applications using more than 8-bit color.

SGImeeting implements an extension to the T.128 application sharing protocol that allows for full 24-bit color application sharing, resulting in no loss of image fidelity. This protocol extension works between SGImeeting desktops, however when a conference includes desktops that are not using the extended protocol, color fidelity falls back to standard T.128. Color fidelity automatically jumps forward again when these desktops leave the conference.


How do I...

control shared applications?
use the shared desktop viewer?
share my applications to other people?
let others work in applications I have shared?
stop sharing my applications to other people?

Controlling Shared Applications

To take control of a shared application, move your mouse cursor over the application window.

If the cursor is a simple "no" symbol, the person hosting the application has not collaborated, so you will not be able to take control of it.
If the cursor is a small "no" symbol overlaid with an arrow, you can request control by clicking on the application window.

When you have control, you will be able to use the application with your mouse and keyboard as if it were running on your local system.

Tip: You can also take control by clicking on the Collaborate button on the SGImeeting toolbar, or choosing the Collaborate... command on the Tools menu.

The Shared Desktop Viewer

When an application is shared from a system with a larger desktop than yours, SGImeeting lets you to view the whole of the application by automatically scrolling shared windows when the mouse cursor nears the edge of the local desktop. This feature can be disabled by deselecting the "desktop scrolling enabled" field in the options.

Selecting Shared Desktop Viewer from the Tools menu displays a window that shows the relative sizes and positions of:

the desktops of everyone in the conference
the shared application windows

You can select which of these are displayed (Desktops, Shared Windows, or both) by right-clicking with the mouse on the shared desktop viewer window, and selecting the appropriate option(s) from the popup menu.

Sharing Applications

To share an application, click the Share button on the toolbar. The mouse cursor becomes a pointing hand. Click on the window you wish to share. When shared, local applications become "tagged" with your name.

Alternatively, you can choose Share Application from the Tools menu. This leads to a list of currently running applications on your system, with a check mark next to those that are currently shared. Selecting an application that is currently not shared from the list causes that application to be shared. Note that not all applications have appropriate labels next to them. This is because some applications are not compliant with standards that allow them to share this information

Notes:

You cannot share SGImeeting windows (such as the whiteboard), or the root (desktop) window.
This release of SGImeeting is optimized for the sharing of 2D X applications. Output drawn using certain X extensions will not be shared. Sharing of output that is drawn directly to the graphics hardware (e.g. 3D applications using OpenGL) is supported, but the level of responsiveness for such applications when controlled by remote users is currently limited compared with 2D applications, unless running on very fast hardware over a high-bandwith network.
You must be running SGImeeting on the same system as the X server in order to share applications to other users.

Letting Others Work in Applications You Have Shared

Other conference participants cannot take control of applications that you have shared until you explicitly permit them to do so by collaborating. To do this, click on the Collaborate button on the SGImeeting toolbar, or choose the Collaborate command on the Tools menu.

When another conference participant is in control, they effectively take over your mouse and keyboard (but can only provide input to shared applications), until you request control back by pressing a key or clicking with the mouse.

To stop collaborating:

if you have control, click the Collaborate button again
if someone else has control, press Escape

Stopping Sharing Applications

To stop sharing an application, click the Unshare button on the toolbar. The mouse cursor becomes a pointing hand. Click on the window you wish to stop sharing. The window "tag" will disappear, indicating that the window is no longer shared.

Alternatively, you can choose Share Application from the Tools menu. This leads to a list of currently-running applications on your system, with a check-mark next to those that are currently shared. Selecting an application that is currently shared from the list causes that application to be unshared. Note that not all applications have appropriate labels next to them. This is because some applications are not compliant with standards that allow them to share this information


Copyright © Silicon Graphics, Inc 1998; Data Connection Limited 1997-1998