Features of UIPACK Version 4

The following major enhancements have been added in Version 4:-

1. Process Support (VAX/VMS only). Subprocesses or Detached Processes may be created by an Application Program and assigned Viewports on the screen. Keyboard Input may be connected to a particular Process and optionally switched between multiple Processes. Processes may run Application Programs that themselves use UIPACK, or ordinary FORTRAN, with the restriction that no Graphics may be accessed by the Processes.
2. Input Logging. All Input to an Application Program may be logged to a File. Logging is thus similar to Learning except that it is under control of the Application Program only and cannot be enabled or disabled by the Operator from the keyboard. Furthermore, Learning is disabled automatically whilst within an Indirect Command File in order to avoid duplication of the Command File specification and the text from within the file, whereas Logging includes all Input, irregardless of whether it comes from the keyboard or an Indirect Command File.
3. Screen Refresh (VAX/VMS only). When UIPACK is in ViewText or ViewCursor Modes, a Ctrl-W (hitting the W key whilst simultaneously holding down the CONTROL or CTRL key) will cause the screen image to be refreshed. This allows a currupted screen image to be recovered.
4. Cancel Handler (VAX/VMS only). An Application Program may optionally setup to detect cancellation signalled by Ctrl-C (hitting the C key whilst simultaneously holding down the CONTROL or CTRL key). This may be used to call a User written AST Subroutine or may be polled by the Application Program. It does not cancel an Input request (either Synchronous or Asynchronous).
5. The Significant Lengths of Verbs, Qualifiers, Parameters, Symbols and Processes may be altered from the default of 8. See the descriptions of UI_DEFINE_VERB_LENGTH, UI_DEFINE_PROCESS_LENGTH and UI_DEFINE_SYMBOL_LENGTH for descriptions of this.
6. UI_TOP_PRIORITY has been modified to not bypass the viewport priority scheme. The Subprogram now raises the priority of the specified Viewport to be greater than any other Viewport. The calling sequence has been modified to add optional arguments to return both the old and new priorities.
7. Optional Arguments have been added to UI_DECODE_FILENAME and UI_GET_FILENAME to return to the Caller whether the specified File exists as well as whether it obeys the correct syntactical rules.
8. Optional Arguments have been added to UI_OUTPUT_TEXT to allow the text to be displayed on a specified Viewport at a specified location in a specified text style.