VIEWPORT

This Command defines a new Viewport or modifies an existing one. It also may be used just to specify the ``current Viewport" used in other Commands (e.g. CHARACTER, DISPLAY, LINE etc.). The position and size of the Viewport on the screen may be specified or modified. Note that the Viewport will not actually become visible until explicitly made so via a DISPLAY Command or a later call to UI_DISPLAY_VIEWPORT.

Parameters

VIEWPORT_ID

Viewport ID. This must either be an Integer lying in the range 0-255 (denoting absolute addressing) or the following syntax may be used:-

VIEWPORT #+n

\

where ``n" is an integer in the range 0-255. (``VIEWPORT #" is equivalent to ``VIEWPORT #+0"). This implies self-relative addressing and the Viewport will be assigned an ID relative to the lowest Viewport ID defined within the file. If absolute addressing is used anywhere within the File, this is the lowest Viewport ID defined. If self-relative addressing is used throughout the File, then this Base ID is the first unassigned ID at the time the file is read and all Viewports will be assigned IDs relative to this. In this latter case the calling program should use the optional arguments to the UI_DEFINE_FILE subprogram to determine which Viewports were actually defined.

The final syntax for specifying Viewport IDs is to use one of the pre-defined Viewport Names below:-

MENU    (0)  Menu Viewport (UIPACK)

TITLE   (1)  Title Viewport (UIPACK)

INPUT   (2)  Input Viewport (UIPACK)

MAIN    (3)  Main Viewport (UIPACK)

HELP    (3)  Help Viewport (UIPACK)

USER    (4)  1st User definable Viewport

USER1  (4)  1st User definable Viewport

USER2  (5)  2nd User definable Viewport

USER3  (6)  3rd User definable Viewport

USER4  (7)  4th User definable Viewport

Note that the MENU, TITLE, INPUT and MAIN (HELP) Viewports are created by UIPACK and therefore cannot be created by this VIEWPORT Command. However, these Viewports may be modified by this Command.

Qualifiers

/GRAPHICS

Overrides the default Viewport Display Mode. The Display Mode is setup be default to be TEXT but can be modified via the MODE/VIEWPORT Command. The presence of this Qualifier will cause the GRAPHICS Viewport to be created. Both the TEXT and GRAPHICS Qualifiers may not be specified simultaneously.

/TEXT

Overrides the default Viewport Display Mode. The Display Mode is setup be default to be TEXT but can be modified via the MODE/VIEWPORT Command. The presence of this Qualifier will cause the TEXT Viewport to be created. Both the TEXT and GRAPHICS Qualifiers may not be specified simultaneously.

/ALERT

Identifies this Viewport as being an Alert Viewport. It will be ``popped" to the front of the screen automatically when it is written to.

/INPUT

Specified this Viewport as being used for subsequent input prompting and echoing of Operator responses rather than the Input Viewport. The INPUT and PROMPT qualifiers are equivalent.

/TRUNCATE

Identifies this Viewport as truncating text that overflows the width of the Viewport. This is the default.

/WRAP

Identifies this Viewport as wrapping text that overflows the width of the Viewport to the next line.

/PRIORITY=<prior>

Specifies the Viewport Priority. This defaults to zero if this Qualifier is absent or has no associated value. A negative priority will prevent the Viewport from being made visible by subsequent DISPLAY Commands until its priority is raised to zero or greater. A Viewport with a high priority will occlude one with a lower priority. The Priority should be specified as an Integer.

/PROMPT

Specified this Viewport as being used for subsequent input prompting and echoing of Operator responses rather than the Input Viewport. The INPUT and PROMPT qualifiers are equivalent.

/X_LOW=<x-low>

This specifies the desired horizontal placement of the low edge of the Viewport. If this Qualifier is omitted (or has no associated value), then either the screen X Low Coordinate will be used (if the Viewport doesn't already exist), or the current X Low Coordinate (if the Viewport already exists). The X-Coordinate should be specified in the units appropriate for the current Viewport Display Mode (See the MODE/VIEWPORT Command). Thus, for TEXT Viewport Mode the units are in Columns and may be specified as Integer or Floating Point Numbers, while for GRAPHICS Mode they are in Graphics Units and must be specified in Floating Point.

/X_HIGH=<x-high>

This specifies the desired horizontal placement of the high edge of the Viewport. If this Qualifier is omitted (or has no associated value), then either the screen X High Coordinate will be used (if the Viewport doesn't already exist), or the current X High Coordinate (if the Viewport already exists). The X-Coordinate should be specified in the units appropriate for the current Viewport Display Mode (See the MODE/VIEWPORT Command). Thus, for TEXT Viewport Mode the units are in Columns and may be specified as Integer or Floating Point Numbers, while for GRAPHICS Mode they are in Graphics Units and must be specified in Floating Point.

/Y_LOW=<y-low>

This specifies the desired vertical placement of the low edge of the Viewport. If this Qualifier is omitted (or has no associated value), then either the screen Y Low Coordinate will be used (if the Viewport doesn't already exist), or the current Y Low Coordinate (if the Viewport already exists). The Y-Coordinate should be specified in the units appropriate for the current Viewport Display Mode (See the MODE/VIEWPORT Command). Thus, for TEXT Viewport Mode the units are in Rows and may be specified as Integer or Floating Point Numbers, while for GRAPHICS Mode they are in Graphics Units and must be specified in Floating Point.

/Y_HIGH=<x-high>

This specifies the desired vertical placement of the high edge of the Viewport. If this Qualifier is omitted (or has no associated value), then either the screen Y High Coordinate will be used (if the Viewport doesn't already exist), or the current Y High Low Coordinate (if the Viewport already exists). The X-Coordinate should be specified in the units appropriate for the current Viewport Display Mode (See the MODE/VIEWPORT Command). Thus, for TEXT Viewport Mode the units are in Rows and may be specified as Integer or Floating Point Numbers, while for GRAPHICS Mode they are in Graphics Units and must be specified in Floating Point.

Qualifiers may be attached either to the Command or to the Viewport ID and thus the following is legal:-

VIEWPORT/XLOW=5/XHIGH=60 USER1/TEXT