The Read Locator Information routine reads information from a
    DECwindows workstation terminal's locator device (such as a mouse
    or tablet).

    Format

      SMG$READ_LOCATOR  keyboard-id ,row-number ,column-number

                        ,word-terminator-code [,timeout]

                        [,parse-routine]

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2  –  Arguments

 keyboard-id

    OpenVMS usage:identifier
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Keyboard identifier. The keyboard-id argument is the address of
    an unsigned longword containing the identifier of the desired
    virtual keyboard.

    You can create a virtual keyboard by calling the SMG$CREATE_
    VIRTUAL_KEYBOARD routine.

 row-number

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference

    Row number to which the locator is pointing. The row-number
    argument is the address of an unsigned word that contains the row
    number of the virtual display at which the locaor is pointing.

 column-number

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference

    Column number to which the locator is pointing. The column-number
    argument is the address of an unsigned word that contains the
    column number of the virtual display at which the read is to be
    performed.

 word-terminator-code

    OpenVMS usage:word_unsigned
    type:         word (unsigned)
    access:       write only
    mechanism:    by reference

    Locator terminator code. The word-terminator-code argument is
    the address of an unsigned word into which is written a code
    indicating what locator button terminated the read. Locator
    terminator codes are of the form SMG$K_TRM_keyname.

 timeout

    OpenVMS usage:longword_signed
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Timeout count. The optional timeout argument is the address of a
    signed longword that contains a number of seconds. If specified,
    any character typed before the timeout is returned in the buffer.

 parse-routine

    OpenVMS usage:longword_unsigned
    type:         longword (signed)
    access:       read only
    mechanism:    by reference

    Address of a user-supplied parse routine that is called to parse
    the locator input. The optional parse-routine argument is the
    address of an unsigned longword that contains the parse routine.
    If this argument is not specified, ANSI locator input is assumed.