The X Window System core protocol is the base protocol of the X Window System, which is a networked windowing system for bitmap displays used to build graphical user interfaces on Unix, Unix-like, and other operating systems. The X Window System is based on a client–server model: a single server controls the input/output hardware, such as the screen, the keyboard, and the mouse; all application programs act as clients, interacting with the user and with the other clients via the server. This interaction is regulated by the X Window System core protocol. Other protocols related to the X Window System exist, both built at the top of the X Window System core protocol or as separate protocols.
In the X Window System core protocol, only four kinds of packets are sent, asynchronously, over the network: requests, replies, events, and errors. Requests are sent by a client to the server to ask it to perform some operation (for example, create a new window) and to send back data it holds. Replies are sent by the server to provide such data. Events are sent by the server to notify clients of user activity or other occurrences they are interested in. Errors are packet sent by the server to notify a client of errors occurred during processing of its requests. Requests may generate replies, events, and errors; other than this, the protocol does not mandate over a specific order in which packets are sent over the network. Some extensions to the core protocol exist, each one having its own requests, replies, events, and errors.
X originated at MIT in 1984 (its current release X11 appeared in September 1987). Its designers Bob Scheifler and Jim Gettys set as an early principle that its core protocol was to "create mechanism, not policy". As a result, the core protocol does not specify the interaction between clients and between a client and the user. These interactions are the subject of separate specifications, such as the ICCCM and the freedesktop.org specifications, and are typically enforced automatically by using a given widget set.
Read more about X Window System Core Protocol: Overview, Windows, Pixmaps and Drawables, Graphic Contexts and Fonts, Resources and Identifiers, Events, Example, Colors, Atoms, Properties, Mappings, Grabs, Other, Extensions, Authorization, Xlib and Other Client Libraries, What The X Window System Core Protocol Does Not Specify
Other articles related to "x window system core protocol, windows, window, protocol":
... The X Window System core protocol does not mandate over inter-client communication and does not specify how windows are used to form the visual elements that are common in graphical user interfaces (bu ... methods used by a user to transfer data from a window to another ... Since the windows may be controlled by different programs, a protocol for exchanging this data is necessary ...
Famous quotes containing the words core, system and/or window:
“Individual science fiction stories may seem as trivial as ever to the blinder critics and philosophers of todaybut the core of science fiction, its essence ... has become crucial to our salvation if we are to be saved at all.”
—Isaac Asimov (19201992)
“We recognize caste in dogs because we rank ourselves by the familiar dog system, a ladderlike social arrangement wherein one individual outranks all others, the next outranks all but the first, and so on down the hierarchy. But the cat system is more like a wheel, with a high-ranking cat at the hub and the others arranged around the rim, all reluctantly acknowledging the superiority of the despot but not necessarily measuring themselves against one another.”
—Elizabeth Marshall Thomas. Strong and Sensitive Cats, Atlantic Monthly (July 1994)
“Tree at my window, window tree,
My sash is lowered when night comes on;
But let there never be curtain drawn
Between you and me.”
—Robert Frost (18741963)