frank@hpcvlo.HP.COM (Frank Hall) (10/26/87)
There have been a number of requests for information about the availability of the Xrlib User Interface Library on the X.11 MIT tape. Hewlett-Packard is pleased to announce that this toolkit has been ported to X.11, is being tested, and will be placed on the December 15 X.11 tape from MIT, along with an interactive suite of tests that verify the quality of an implementation of the library on a specific hardware architecture or operating system. As with the X.10 release of the library, HP's goal with this release is to stimulate formation of ease-of-use software on X workstations by assuring that there is a stable, product-quality UI toolkit available to the open X community. To assist in the porting of applications between the X.10 and X.11 releases, no changes to the programmatic interface have been made except where required by the unavoidable differences between X.10 and X.11. These changes are summarized below. Note that Hewlett-Packard also strongly endorses the efforts at standardization of a UI toolkit above the X level. To that end we began working in November, 1986, with DEC and MIT, on the X Toolkit. Our participation was primarily in the design phase, though we also contributed a couple of widgets to the X.10 version. DEC supplied the recent design and implementation and, to their credit, provided on the September X.11 tape a new version whose architecture has a greatly expanded set of possibilities. This change was revolutionary, as predicted last spring. Changes beyond this point will hopefully be evolutionary, so the Toolkit can be meaningfully submitted to a standards body next year. The intrinsics are stable or nearly so, but more work does need to be done in smoothing out widget class architecture and in providing even better widgets. Hewlett-Packard is developing a set of easy-to-use Toolkit widgets which will allow developers to create interfaces similar to, and even better than, those possible with the Xrlib library. We intend to place these in the public domain as well, but aren't promising them by December. We are open to your input. If you have questions, or comments about widget/field editor needs, please state them in this forum, so all can be informed and involved. Regards, Frank Hall Technical Computer Group Hewlett-Packard frank@hpcvlo.HP.COM ======================================================================== SUMMARY OF XRLIB CHANGES BETWEEN X.10 AND X.11 ---------------------------------------------- Overall, the effort of porting an existing X.10 Xrlib application to X.11 is minimal, with most of the effort due to changes in Xlib, rather than Xrlib. Some changes within Xrlib have been caused by structures changing between X.10 and X.11; among these are the FontInfo structure, bitmaps, fonts and the event structure. Additionally, since XrInit() allocates a set of default resources for the application, the call to XrInit() now requires a display pointer and a screen index as parameters. This call occurs only once in each application. Another area of change within X-ray deals with window functions. Under X.11 the xrWindowEvent structure will now be broken up into three fields, matching the format imposed by X.11. The information needed to describe a window function event will be composed of an event type, a list of modifiers and a code. One change within X, which all users will want to be wary of regardless of Xrlib use, is the XEvent structure. Under X.10, all of the assorted, uniquely named event structures were the same size. This allowed an application to pass a pointer to any X event structure to XNextEvent() or to XrInput(). Under X.11, unique event structures are no longer are required to be the same size; only the generic XEvent structure is guaranteed to be large enough to hold any event. Therefore, any applications which read input into any event structure other than the XEvent structure, will be required to change.