APDL Public Domain 1/APDL_PD1A.iso/textutil/jgpsuite/Docs/JGPCopyDoc

Text File | 1993-04-19 | 12.5 KB | 282 lines

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|JGPCopy and Handler v1.20|Fri,03 Jul 1992

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|JGPCopy
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This Document and all files in !jgp and !jgpcopy are (C) JGLaski, 1993. A Free
license is given for this document and all files in !jgpcopy on condition that
every reasonable effort is made to pass it on and bring it into use, and that no
modifications are made to any file, other than bracketted and acknowledged
extensions and corrections.

This document is not a specification of the programmes it describes, and no
warranty is given that they work as described herein, nor any responsibility
assumed for any consequence of their use.

It is, of course, my practice to develop the code both for reasons of discovered
bugs and worthwhile new ideas, and also to take reasonable care to make sure
that the code is free from non\-trivial bugs.

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|-oOo-

The tool JGPCopy is supplied both as part of the the !jgp suite, and on its own
within the !jgpcopy application. Its purpose, roughly, is to type any file
either to the screen or dump it, paging as it goes, or pass it to the printer.
It releases the processor, when it does not need it, to any other programs that
are running in the desktop. To Screen, it engages the whole screen for its
display and seeks to purge a file of any printer codes. Its run may always be
cancelled part way through, as documented on the screen. It can also dump the
file to screen, and, if required, spool that dump to a file.

If printer codes are included in the file to move the printhead, JGPCopy cannot,
in general, understand them when copying to screen; however, if it believes a
code to be a horizontal motion, it will insert a space. The effect, in practice,
is to separate words by a space, and move margins, tabs and colled fields to the
left. Of course, if the JGPCopy file has been JGPrinted with a screen
configuration such as Default, JGPCopy will reproduce the original effects.

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|-oOo-

The application !jgpcopy provides a handler to users of the tool JGPCopy,
the final program available in the suite !jgp. JGPCopy will be applied, under
either handler, to a file of type JGPCopy when double clicked. (Currently (9/91)
JGPCopy is &205, but I expect a change shortly. It should be sufficient to
edit the numbers in the !jgpcopy.!boot file, the !sprites file and the Templates
file; I do not believe any code will require change.) Any file, of whatever
type, dragged to a JGPCopy icon on the icon bar will also have JGPCopy applied
to it.

!jgpcopy will only register its icon if !jgp has not been encountered, and
double clicking on !jgp will cause the icon from !jgp to supersede it; any
JGPCopy runs will continue unaffected under the new management. Under !jgp,
both means of applying JGPCopy remain available, but, to get a JGCopy icon on
the bar, you must first choose jgpcopy in the icon bar's menu; the icon
mutates back to a JGEd icon after use.

(To test !jgpcopy, if you have also got !jgp, quit in the !jgp icon in the
icon bar and also UNSET jgp$dir. Then double-click on !jgpcopy. You will have
lost access to JGEd, JGPrint and JGConfig. Double clicking on !jgp will restore
!jgp without !jgpcopy. There is a bug, and you should exit !jgpcopy before
double clicking on !jgp)

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|-oOo-

Through its menus, JGPCopy is virtually self\-documenting. For each file
submitted to JGPCopy (whether by double clicking a JGPCopy file or by dragging
any file to the JGPCopy icon bar icon) an icon with that file's name will be
entered on the icon bar, and clicking menu on this icon opens the main menu
controlling what happens to it. If you are using JGPCopy within !jgp, selecting
jgpcopy from JGEd's icon bar icon menu mutates the JGEd icon until a file is
dragged to it. Double clicking on a JGPCopy file opens the menu near your
pointer.

To Screen, To Dump, and To Printer are the principal choices, and Options
provides a submenu to control how this is done.

+Quit and +Delete file are two options that apply to both choices; if you stop
printing or quit copying before the end, they will not apply. <nl> -> <cr>,
default ticked, enables C type files to be correctly handled. If you want <10>
to be interpreted as a downtab without carriage return, untick it.

For To Screen, the most important option is Mode. Clicking on the blue arrow in
the mode window cycles 16 colour modes; I find 12, 20 and 16 the most useful.
The other option is concerned with how to treat printer codes found in text.
There is a choice between assuming Epson style, assuming HP style and printing
characters from codes. Bytes 0-31 are interpreted if their function is to move
the screen cursor, otherwise replaced by a space.

The text is paged to the screen; a special line at the bottom of the page tells
you how to continue or quit.

For further details of how codes are scythed from the text see below.

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|-oOo-

The JGPCopy files produced by JGPrint are closely analogous to the Printout
files(FF4) produced by !Printers, and, with care, can be used interchangeably.

JGPCopy uses JGPrSlave to actually do the printing, but the arrangements are
very different in !jgpcopy and !jgp.

In !jgpcopy JGPrSlave is a direct slave of JGPCopy without involving !printers.
Multi\-tasking is not available, and you must ensure that other sources of
printing do not conflict with this use of the printer.

More flexibility is provided in !jgp; alias$@Printtype_205 is set to
.....!jgp.Runimage 4. If JGPCopy sends appropriate messages to !Printers, or a
JGPCopy file has been dragged to !printers, !printers can queue the printer
request and JGPrSlave will print it.

In the option menu of !jgp, you can choose whether or not JGPrSlave should
attempt to multitask; you can request JGPrSlave to pause, and you can stop
JGPrSlave.

JGPCopy files produced by JGPrint may, if requested in the initial dialogue,
contain the pseudo printer directive <esc><esc>, which will cause JGPrSlave to
put up a verso window to enable paper to be turned round, or directives
<esc>0<n> at the beginning of Page <n>, to enable a pause for each page to be
set in the printer. In both !jgp and !jgpcopy, these will set JGPrSlave to
multitask.

These pseudo directives have been chosen, as far as possible, not to affect the
printer and not to pre/-empt existing printer directives.

For files produced by JGPrint to be used via a !Printers' printer, there must be
consistency between the configuration used in JGPrint and that printer. In the
paragraphs below, printer signifies a !Printers printer.

There are three matters to consider: initialising printer-code; printer X & Y
offset; character mapping.

A JGPCopy file has its own printer initialisation code at its head. !Printers
will precede this by its own initialisation code. It is necessary that the
former cancels any effects of the latter that will precede it. In effect, the
init code in the JGPrint configuration file should start by a printer code to
set the printer state to its default values. (Epson is <esc>@, HP is <esc>E.)

If you have set printer Y offset non-zero, the effective pagelength will be
reduced by the amount set; use the config size skiplength to apprise JGPrint of
this reduction. If you have set X offset non-zero, you may have to adjust your
margins, and you may not be able to print as wide a text as JGPCopy will permit
directly.

If the printer has defined a character mapping for top-bit set characters, it
may transform bytes sent by JGPCopy. This may be significant in two contexts: if
the JGPrint configuration has itself generated top-bit set characters which it
wishes to put out verbatim; if bytes > 128 are put out as parameters to printer
directives. £ is the major problem in the first case, though hatty characters or
insert may have put top-bit set characters into the text. The second may be a
problem if your text contains epson style codes.

I recommend careful checking if you propose to use !Printers in association
with JGPCopy files.

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|-oOo-

More about Scything codes from the text:-

The option that selects between None, Epson, HP, etc. style codes controls an
attempt to scythe, from the text copied to screen, noise from printer commands.
Remember that horizontal and vertical setting commands will not be effected on
the screen, so that what shows on the screen may not be exactly laid out as it
would be if JGPrinted directly. It is possible that some codes may not be
correctly recognised, though I have had no problem from any I have tried.
Moreover, bytes that will mess up the screen never get through. Each such
command is replaced by a space, in order to separate words on the screen.

If a file has come from MSDOS and uses ANSI-standard commands to manipulate the
window, HP-style codes may succeed in scything them out; however, I have
encountered some whose terminator is lower case, which, if used, will cause too
much to be missed. It may be possible to modify the definition of valid code,
described below.

Those who have FormEd can change the initial selection by editing a window in
the Template file in !jgp and/or !Jgcopy; also the Codes recognised as valid can
be modified. See details below   (To be implemented only on request.)

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|Technical Note

The problems are quite different in Epson-style and HP-style codes. In each,
there are 2 problems.

In Epson\-style, the problems come from those codes that are required to be
followed by bytes that may be screen\-displayable: either 1 byte as in, for
example, the code for a vertical tab; or to be followed by 2 bytes, as for
example, the codes to move the print head either relatively or absolutely.

In HP-style codes, there are two classes of codes that do not have @, A-Z as
terminators. The first has a single character following <esc>, and I have
encountered the usages '=' for half\-line\-feed and '9' to clear margins. The
second has a lower case letter terminal after 3,4,6,...characters. I have
encountered these forms in bringing across MSDOS files that use (an extension
of) the ANSI standard codes to manage modes and cursor. I have seen f,s,u,n,m,h,
used, respectively, as terminators for Horizontal and Vertical Position,
Save/Restore Cursor Position, Device Status Report, Set Graphics Rendition, Set
Mode.

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|Amending facilities

To amend the code-style initially chosen, double click on the file Templates in
!jgpcopy and/or !jgp. The window you want has, as Title, Printer Codes Ignored,
and as Identifier, Scythe.

You want to amend the sprite icons to the right of Epson and HP respectively so
that the one to the right of your choice is the one whose sprite name is pgo. A
convenient name for the other is pwait. (These icons are coloured circles used
in the printer window.)

More precisely, IF Epson+1 is pgo THEN the Firstchoice is Epson ELSEIF HP+1 is
pgo THEN Firstchoice is HP ELSE Firstchoice is none.

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|not implemented Mon,06 Apr 1993

Below Epson and Hp are two Sprites in which are listed the characters following
<esc> that are to be specially treated in the respective ways described
above, the first described in the window immediately below the printer name, and
the second in the bottom window. The number of characters that can be entered in
these windows is limited to 12. Those shown in the window provided are presently
built in to JGPCopy.

It is, of course, vital not to renumber the sprites in the Scythe window.

If your printer has a code-style that does not fit into this framework, I should
be glad to discuss appropriate customising.

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|-oOo-

I do not charge for a licence to use JGPCopy from within !jgpcopy.

However, if you find yourself regularly making use of it, other than to read
the documentation of material with which it was distributed, without having
bought a licence for JGEd or JGPrint, you should make whatever donation you
think suitable to an arts or higher education charity of your choice, and I
request you to send me any  programs for which you are entitled to give me a
licence and that you think might interest me.

If you distribute documentation with !jgpcopy, as a condition of a free licence
to do so, I require you to distribute the shareware JGP disc at whatever
handling charge you deem fair.


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| |J.G.Laski      |
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| |18 Ebury Street|
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| |London         |
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| |SW1W OLU       |
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| |\d