lps_setcontext

<B>Digital的Unix操作系统VAX 4.2源码</B>

% LPS$$SETCONTEXT device control library module.
% Version V1.1
%
% Copyright ) 1986 by DEC, Maynard, Mass.  All rights reserved.
%

% Remember, you are still in lps$lpsdict!

% Select paper tray.
%

    /lps$current-sheet papersize pop def	% The current sheet size name

    lps$sheet-defaulted not			% If we want a particular size
    {	paper-size-dict lps$sheet-size get	% The op for the size we want
	dup
	lps$current-sheet ne			% If we don't have what we want.
	{   lps$input-tray (unspecified) eq	% If we don't care which tray,
	    {	dup /lps$current-sheet exch def	% Save new current sheet name.
		dup cvx				% Make a copy of the size op
		{   exec }			% Select the size with it,
		stopped				% but catch a rangecheck
		{   (\n        Your job was not printed because ") print
		    20 string cvs (tray) search pop print lps$pop2
		    (" size paper\n        was not present in )
		    print 31 string printername print (.\n) print flush
		    $error /newerror false put	% Suppress original message
		    stop }			% Trigger error again
		{   pop }			% Dump the extra paper size
		ifelse }
	    {					% If we do care which tray,
		pop				% It's selected. Don't need op

		(\r\n        Your job is not being printed because ") print
		papersize pop 15 string cvs (tray) search pop print lps$pop2
		(" size paper was\r\n        found in the ") print
		lps$input-tray print (" paper tray when you specified ") print
		lps$sheet-size print (" size paper.\r\n) print flush stop
		}
	    ifelse  % lps$input-tray (unspecified) eq
	    }
	{   pop }				% Scrap the dup'ed op.
	ifelse	% current-sheet ne
	}
    if	% lps$sheet-defaulted not

    % 
    % Do we need page layup?
    %
    
    lps$page-layup?
    {	lps$page-layup-dict begin

	    % Set params: sheet size, page size, page-orient.

	    mark
		842 1190    /a3tray
		596 843	    /a4tray
		420 596	    /a5tray
		729 1033    /b4tray
		516 729	    /b5tray
		540 756	    /executivetray
		396 612	    /halflettertray
		612 792	    /lettertray
		792 1224    /11x17tray
		612 1008    /legaltray
	    counttomark 1 add copy
	    {	% Loop along the table.
		dup mark eq { exit } if		% An escape if no name matches
		lps$current-sheet eq		% When we find the name,
		{   set-sheet-size exit }	% The sheet size is underneath
		if
		pop pop				% Pop this size
		}
	    loop cleartomark			% Dump the end of the table.

	    /lps$page-size-name paper-size-dict lps$page-size get def

	    {	% Loop along the table above.
		dup mark eq { exit } if		% An escape if no name matches
		lps$page-size-name eq
		{   set-page-size exit }
		if
		pop pop
		}
	    loop cleartomark

	    lps$page-orientation (portrait) eq set-orientation

	    do-page-layup
	    plu-hooks				% Get the hooks dict
	    end					% lps$page-layup-dict
	2 { currentdict end } repeat
	3 -1 roll				% Pull up the hooks
	3 { begin } repeat			% Dicts: sys usr plu stat lps
	}
    if

    % Possibly redefine showpage et.al. for sheet limit.
    % Our current dictionary is lps$lpsdict.

    /lps$old-copypage /copypage load def % Preserve context
    /lps$old-restore /restore load def % Preserve context
    /lps$old-showpage /showpage load def % Preserve context

    lps$page-limits?
    {
	% increment lps$pages-printed by 1.
	%

	/lps$incr-pages-printed {
	    lps$lpsdict /lps$pages-printed	% Put on the stack for put.
	    2 copy get 1 add put
	    } bind def

	% Add to the list of objects whose value is to be preserved
	% across restore.
	%

	/lps$pages-printed lps$add-preserved-object

	% If a page is outside the range of the page limits, don't print
	% it, just clear the memory.
	%

	/lps$throw-out-page {erasepage initgraphics} bind def
    
	/showpage {
	    lps$pages-printed lps$page-low-limit lt % printed < low-limit
	    {	lps$throw-out-page
		lps$incr-pages-printed }
	    {	lps$page-high-limit 0 ne	% There is an upper limit
		{   lps$page-high-limit lps$pages-printed lt
		    {	lps$page-layup? % Check for partial pages under layup.
           		{  lps$page-layup-dict begin flush-pages end  } if
                        (\n       The upper limit of your job has been reached.)
			print
			(\n       The rest of your job will be flushed.)
			print flush
			stop }			% The job is done
		    {	lps$old-showpage
			lps$incr-pages-printed
			}
		    ifelse }
		{   lps$old-showpage }
		ifelse }
	    ifelse				% No upper limit, print page.
	    }
	bind def

	/copypage {
	    lps$pages-printed lps$page-low-limit lt
	    {	lps$incr-pages-printed }	% No output, just save bitmap
	    {	lps$page-high-limit 0 ne	% There is a high limit
		{   lps$page-high-limit lps$pages-printed lt
		    {	(\n       The upper limit of your job has been reached.)
			print
			(\n       The rest of your job will be flushed.)
			print flush
			stop }			% The job is done
		    {	lps$old-copypage
			lps$incr-pages-printed
			}
		    ifelse }
		{   lps$old-copypage }
		ifelse }
	    ifelse				% No upper limit, copy page.
	    } bind def
	}
    if


    % See if restore needs to be redefined because of variables that must be 
    % preserved across restores.

    lps$redefine-restore?
    { /restore {
        lps$preserved-objects
        { pop dup load
	  }
        forall  % Save key value pair on stack
        lps$preserved-objects length mul 2 1 add -1 roll % bring up save level
        lps$old-restore
        lps$preserved-objects length -1 1
        { pop store
	  }
        for
        } bind def
      }
    if

    % These two functions are used by the file flag and trailer pages to make
    % sure that they aren't under the influence of some of the weird stuff
    % we've been doing here.

    /lps$enter-standard-state {
	% First make sure any partially filled sheet is output.

	lps$page-layup?
	{   lps$page-layup-dict begin
		flush-pages
		end
	    }
	if

	save
	systemdict begin
	userdict begin
	/lps$strange-state exch def		% Save the save level

	initgraphics erasepage			% Insure a clean slate
	/#copies 1 def				% Don't want duplicates

	} bind def

    /lps$exit-standard-state {
	lps$strange-state			% Get the save level
	end end					% Pop userdict and systemdict
	restore
	} bind def

    % Now we prepare the user's context. If we are using page layup, then the
    % proper hooks dictionary is already buried in the dictionary stack, so
    % we don't have to consider it explicitly here.

    end end					% lps and stat
lps$lpsdict begin				% sys usr plu? lps
  userdict begin				% sys usr plu? lps usr