(LOGO.JPG) Python for OpenVMS

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ERASE_DISPLAY - Erase Virtual Display

Erase all or part of a virtual display by replacing text with blanks.

Format:

    vms_smg.erase_display (display_id,                 \
                          [start_row], [start_column], \
                          [end_row], [end_column])
Returns:

None

Arguments:

display_id
Virtual display from which to erase text.
start_row
Line number at which the erase operation begins.
start_column
Column number at which the erase operation begins.
end_row
Line number at which the erase operation ends.
end_column
Column number at which the erase operation ends.
Examples:
>>> import vms_smg
>>> import vms_smgdef

>>> # create a new DECwindows terminal using SMG
>>> status, pasteboard_id, number_of_pasteboard_rows, \
... number_of_pasteboard_columns, type_of_terminal,   \
... device_name = vms_smg.create_pasteboard           \
...   (None, vms_smgdef.SMG_M_WORKSTATION)
>>>

>>> # create virtual display
>>> status, vtdpy1 = vms_smg.create_virtual_display \
...         (5, 10, vms_smgdef.SMG_M_BORDER, None, None)
>>>

>>> # paste virtual display
>>> status = vms_smg.paste_virtual_display \
...          (vtdpy1, pasteboard_id, 3, 5, None)
>>>

>>> # put characters on virtual display
>>> status = vms_smg.put_chars (vtdpy1, '1234567890', 1, 1)
>>> status = vms_smg.put_chars (vtdpy1, 'ABCDEFGHIJ', 2, 1)
>>> status = vms_smg.put_chars (vtdpy1, 'KLMNOPQRST', 3, 1)
>>> status = vms_smg.put_chars (vtdpy1, 'abcdefghij', 4, 1)
>>> status = vms_smg.put_chars (vtdpy1, 'klmnopqrst', 5, 1)
>>>

Screen layout, file: VMS_SMG_008.JPG

(picture VMS_SMG_008.JPG)

>>> # erase from virtual display
>>> vms_smg.erase_display (vtdpy1, 2, 2, 3, 6)
>>>

Screen layout, file: VMS_SMG_023.JPG

(picture VMS_SMG_023.JPG)

>>> # erase the whole display
>>> vms_smg.erase_display (vtdpy1, None, None)
>>>
The virtual display is empty, the cursor is positioned at the upper left-most corner.


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10-SEP-2000 ZE.