X-Windows Programming Laboratory
#1

[attachment=14059]
Introduction
Overview of X Windows
X11 Release 5 came out in August 1991. The heart of the X Windows system consists of a
program called X which runs on a machine with a display, keyboard, and a mouse. It waits for
other programs to tell it what to do or for something to happen to the pointer or keyboard. The
programs can be running on the same machine as X is or elsewhere on the network, maybe on a
machine that hasn't even got a display of its own. This `network transparency' is one of the
strengths of X. Graphics programs only have to know about X, not about the special low level
graphics commands for each type of machine. The client programs communicate to X, the
server, via a Protocol language that is common across machine types.
All a client program needs to do to use the X display is to open up a connection with the server
and then send Protocol requests to it. To simplify sending these, an extensive library of about
200 display subroutines is provided and it is this library, Xlib, which this document mainly
describes.
Many client programs can simultaneously use the same X server. To save each client having its
own copy of fonts, color information, etc, (thereby wasting space and causing more data to be
passed via the network), the server stores data on behalf of the clients, allowing sharing wherever
possible. In order to enable the client to reference these resources the server provides resource
codes and these can be used in many of the routines to specif y that certain data is to be used.
X is `event driven'. For each window you create you can select what sort of events (key presses,
re-exposure, etc) you want it to respond to. Typically, an X program consists of a set-up
sequence followed by an `event-loop' which waits for events to be reported by the server,
determines what sort of event has happened and in which window, then processes the event.
Both display requests and events are buffered and the server executes asynchronously much of
the time to maximise efficient use of the network. When the client wishes to establish
it often has to ask for it, though working in synchronized mode can be up to 30
times slower, so only use it for debugging.
X clients programs should be written mindful of the fact that other clients are likely to be
running at the same time. Windows should be prepared to be covered over by others then
exposed, and they have to redraw themselves.Neither should client’s indescriminately use scarce
resources like off-screen memory or monopolise the keyboard or pointer.If can they accept cut-
and-paste operations, so much the better.
One application that is always likely to be running is a `window manager'; a program which
allows you to resize, move and re-stack windows, pop menus up, etc. Any X application you
write will need to work under a window manager. Some window managers are more bossy than
others (some won't let you raise windows, for instance), but there are X commands so that a
client can at least make suggestions to the window manager.
X can support one or more screens containing overlapping (sub) windows and works on many
types of hardware but it doesn't provide high level support. If you want to prefabricate dialog
boxes from pre-defined scrollbars, buttons, etc then you should use a `toolkit' that sits on top of
X. See the Motif manuals and on-line help for details.
X is extensible. Release 4 of X included the SHAPE extension which provides non-rectangular,
disjoint windows. Neither the use nor the writing of such extensions will be covered in this
document.
In the bad old days Linux, like its parent UNIX, lacked a decent graphical user interface.This led
to the howls of protest from users around the world of Linux being as much cryptic as other
UNIX derivatives. It was rightly tagged as the OS of the geek. The X Window System lends a
face to Linux.
Reply

Important Note..!

If you are not satisfied with above reply ,..Please

ASK HERE

So that we will collect data for you and will made reply to the request....OR try below "QUICK REPLY" box to add a reply to this page
Popular Searches: a seminar on a remote control engineering laboratory, control automatic laboratory ppt, vb6 laboratory project, laboratory management system project in vb 2010, medical laboratory management system, laboratory charter, student laboratory notebook,

[-]
Quick Reply
Message
Type your reply to this message here.

Image Verification
Please enter the text contained within the image into the text box below it. This process is used to prevent automated spam bots.
Image Verification
(case insensitive)

Possibly Related Threads...
Thread Author Replies Views Last Post
  Dynamic programming language seminar projects crazy 2 3,179 03-01-2013, 12:31 PM
Last Post: seminar details
  SEMINAR ON MICROENGINE PROGRAMMING IN NWP computer girl 0 992 09-06-2012, 03:09 PM
Last Post: computer girl
  UAV DevBoard: Getting Started with PIC Programming computer girl 0 1,011 09-06-2012, 11:35 AM
Last Post: computer girl
Music D Programming Language Computer Science Clay 2 2,563 14-03-2012, 02:35 PM
Last Post: seminar paper
Thumbs Down Extreme Programming (XP) computer science crazy 2 2,071 14-03-2012, 11:57 AM
Last Post: seminar paper
Photo Genetic Programming (Download Full Report And Abstract) computer science crazy 3 3,847 29-02-2012, 09:35 AM
Last Post: seminar paper
  GENETIC PROGRAMMING A SEMINAR REPORT Computer Science Clay 3 4,336 29-02-2012, 09:35 AM
Last Post: seminar paper
  Introduction to the C Programming Language seminar class 1 6,575 14-02-2012, 01:43 PM
Last Post: seminar paper
Brick Categorization of Programming Languages computer science crazy 1 1,861 14-02-2012, 01:43 PM
Last Post: seminar paper
  D (programming language) seminar surveyer 2 2,656 14-02-2012, 01:43 PM
Last Post: seminar paper

Forum Jump: