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NeWS – Network Extensible Window System

NeWS ( Network extensible Window System ) was awindowing system developed bySun Microsystems in the mid-1980s.Originally known as "SunDew",its primary authors wereJames Gosling and David S. H. Rosenthal . The NeWSinterpreter was based onPostScript (as was the laterDisplay PostScript, although the two projects were otherwise unrelated) extending it to allow interaction and multiple "contexts" to support windows. Like PostScript, NeWS could be used as a complete programming language, but unlike PostScript, NeWS could be used to make complete interactive programs with mouse support and aGUI.

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Design [ edit ]

NeWS started by implementing a PostScript interpreter running in a cooperative multitasking fashion, since, unlike PostScript in a printer, NeWS would be displaying a number of PostScript programs at the same time on one screen. It also added a complete view hierarchy, based on viewports known as canvases , and a synchronous event distribution system, supporting events , interests , threads and monitors .

Like the view system in most GUIs, NeWS included the concept of a tree of embedded views along which events were passed. For instance, a mouse click would generate an event that would be passed to the object directly under the mouse pointer, say a button. If this object did not respond to the event, the object "under" the button would then receive the message, and so on. NeWS included a complete model for these events, including timers and other automatic events, input queues for devices such asmice andkeyboards, and other functionality required for full interaction. The input handling system was designed to provide strong event synchronization guarantees that were not possible with asynchronous protocols like X. [1]

To support user interface widgets, NeWS expanded the original PostScriptstack-based language into a completeobject oriented (OO) programming style withinheritance. This eliminated the need for an external OO language to build a complete application.

Since all of these additions were implemented as extensions to PostScript, it was possible to write simple PostScript code that would result in a running, onscreen, interactive program. Two popular demonstration programs were an onscreen clock, which required about two pages of code, and a program which drew a pair of eyes that followed the cursor as it moved around the screen. The eyeball program was shown at SIGGRAPH in 1988, and was the inspiration for the later well-known X applicationxeyes.

NeWS included several libraries of user interface elements (widgets), themselves written in NeWS. These widgets ran all of their behaviour in the NeWS interpreter, and only required communications to an outside program (or more NeWS code) when the widget demanded it. For example, a toggle button’s display routine can query the button’s state (pressed or not) and change its display accordingly. The button’s PostScript code can also react to mouse clicks by changing its state from "pressed" to "not pressed" and vice versa. All this can happen in the windowing server without interaction with the client program, and only when the mouse is released on the button will an event be sent off for handling. This was more sophisticated than theX Window System server model, which can only report "mouse was pushed down here", "mouse is now here", "mouse was released here" events to a client, which then has to figure out if the event is in the button, switch the state, and finally instruct the server to display the new state. If client and server are not on the same machine, these interactions must travel over the network, which results in a delay in responding .

NeWS was architecturally similar to what is now calledAJAX, except that NeWS coherently:

  • used PostScript code instead ofJavaScript for programming.
  • used PostScript graphics instead ofDHTML andCSS for rendering.
  • used PostScript data instead ofXML andJSON for data representation.
NeWS – Network Extensible Window System

TNT-based applications

The best example of such a library is TNT ( The NeWS Toolkit ) which Sun released in 1989. Sun also shipped an earlier "Lite" toolkit intended for example purposes and making small programs.

Licensing [ edit ]

Although adoption was never widespread, several companies licensed NeWS and adapted it for various uses.

  • SGI used a version of it named4Sight to replace their proprietaryMEX windowing system.
  • Grasshopper Group created a Macintosh port called MacNeWS.
  • Architech Corporation ported NeWS toOS/2

Applications [ edit ]

TheOPEN LOOK version of theFrameMaker desktop publishing program, developed by Frame Technology Corp with funding mainly fromSun Microsystems andNSA, was one of the few commercial products that ran on NeWS.HyperLook, developed byArthur van Hoff atThe Turing Institute, was an interactive application design system.Don Hopkins developed a NeWS version ofSimCity that was built withHyperLook.

A commercial drawing program, AltSys Virtuoso, was produced for NeWS; it was a port of FreeHand with additional functionality that took advantage of the PostScript environment. Unfortunately Sun announced the end of support for NeWS just as Virtuoso became ready to ship.

Competition with X Window System [ edit ]

The first versions of NeWS emulated the X10 protocol by translating the calls into NeWS PostScript. Speed problems plus the existence of programs that relied on the exact pixel results of X10 calls, and the obsolescence of X10, forced Sun to release an X11/NeWS hybrid called Xnews which ran an X11 server in parallel with the PostScript interpreter. This seriously degraded the NeWS interpreter performance and was not considered a very good X11 server either. Sun also implemented the OPEN LOOK user interface specification in several toolkits: The NeWS Toolkit (TNT) was an OPEN LOOK toolkit written in PostScript that ran in the NeWS server.OLIT was built on the sameXt (X Intrinsics) base asMotif, andXView used the sameAPIs as Sun’s earlierSunView window system.

After it was clear that OPEN LOOK had lost out to Motif in popularity, and afterAdobe acquired FrameMaker, Sun stopped supporting NeWS, and products on NeWS simply vanished. MostUnix workstations (including Sun’s own) now run the X Window System.

References [ edit ]

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