Browse Prior Art Database

Method to Support X Windows Conference Enabled Applications That Perform Active and Passive Grabs

IP.com Disclosure Number: IPCOM000122967D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 4 page(s) / 201K

Publishing Venue

IBM

Related People

Ansberry, CM: AUTHOR [+3]

Abstract

X Windows provides distributed client/server support for two dimensional graphics applications. The application connects to an X server and communicates with it using X protocol, asking the X server to create resources such as windows on the server. The X server then communicates the user interactions with the keyboard and/or pointer to the application via X protocol events. X App | X Server | Display

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This is the abbreviated version, containing approximately 24% of the total text.

Method to Support X Windows Conference Enabled Applications That
Perform Active and Passive Grabs

      X Windows provides distributed client/server support for two
dimensional graphics applications.  The application connects to an X
server and communicates with it using X protocol, asking the X server
to create resources such as windows on the server.  The X server then
communicates the user interactions with the keyboard and/or pointer
to the application via X protocol events.
                               X App
                                 |
                              X Server
                                 |
                              Display

      Under normal operation, the X server is free to service many
applications simultaneously, drawing to each application window and
providing input events to each application as the user interacts with
its windows via the keyboard and/or mouse.  X Windows also allows an
application to request that the X server provide it special
privileges, in essence allowing an application to "grab" certain
devices for its exclusive use.  Because any grab requests interfere
with the processing  of other applications sharing the X server, it
is generally considered  anti-social for an application to
excessively take advantage of these privileges.  However, the use of
this feature of X Windows, when done in  a sociable manner, can
provide important capabilities for an application.

      Via the X protocol, an application may request that all
keyboard inputs and/or pointer inputs be directed to a certain
application, thus preventing the user from interacting with any other
applications active on the X server.  This ability to grab the input
devices is allowed in two forms: passive grabs and active grabs.  An
active device grab (either a GrabKeyboard or a GrabPointer in the X
protocol), indicates that the application referred to in the request
to the X server will be the only application to receive that device's
events while the grab is active.  A passive grab (either a GrabKey or
GrabButton X protocol request ) requests that the X server grant an
active grab to the application the next time a specific set of key or
button events are activated by a user.  When a passive grab is
converted to an active grab because of a user interaction, it behaves
identically to an active grab that was explicitly requested by an
application.

      Both active and passive device grabs are only released when an
application explicitly "ungrabs" the device.  At that point, the X
server returns to processing each application and all user inputs in
a normal  manner.

      When an X Windows application is conference-enabled, the
application connects to an X Window conference-enabler rather than
the X Server.  An X Window conferencing enabl...