Re: fltk printing

[Ben Abbott]

On Aug 7, 2010, at 8:16 PM, Ben Abbott wrote:

> On Aug 7, 2010, at 8:00 PM, Dmitri A. Sergatskov wrote:
> 
>> On Sat, Aug 7, 2010 at 6:37 PM, Michael D Godfrey
>> <address@hidden> wrote:
>> 
>>> It may be good to look at the drawnow code.
>>> 
>> 
>> Here is some interesting test:
>> 
>> # drawnowt.m
>> backend("fltk");
>> plot(1:2);
>> drawnow("eps","junk111.eps");
>> 
>> running
>> octave < drawnowt.m
>> 
>> results in:
>> 
>> warning: implicit conversion from matrix to sq_string
>> error: fltk_backend: could not recognize fltk index
>> error: called from:
>> error:   /home/dima/src/octave/scripts/miscellaneous/delete.m at line
>> 48, column 1
>> error:   /home/dima/src/octave/scripts/plot/closereq.m at line 37, column 7
>> error:   /home/dima/src/octave/scripts/plot/close.m at line 63, column 5
>> error:   /home/dima/src/octave/scripts/plot/close.m at line 77, column 1
>> error:   /home/dima/src/octave/scripts/plot/close.m at line 57, column 5
>> error:   /home/dima/src/octave/scripts/plot/__go_close_all__.m at line
>> 27, column 3
>> 
>> If I add at the end of the test file "pause(0)" it finishes correctly.
>> That suggests me that drawnow spawns some  asynchronous processes.
>> 
>>> Michael
>>> 
>>> 
>> 
>> Sincerely,
>> 
>> Dmitri.
>> --
> 
> Very strange ... The error doesn't give any indication of your test file, 
> drawnowt.m.
> 
> I can'f find any instance where __go_close_all__ is called in the sources. 
> 
> I tried you example on MacOS X, and as expected, no error.
> 
> Ben

sigh : -( ... my bad. __go_close_all__ can be called by drawnow() in 
graphics.cc (I had misplaced a trust in MacOS X's finder).

>From graphics .cc ...

5775 DEFUN (drawnow, args, ,
5776    "-*- texinfo -*-\n\
5777 @deftypefn  {Built-in Function} {} drawnow ()\n\
5778 @deftypefnx {Built-in Function} {} drawnow (\"expose\")\n\
5779 @deftypefnx {Built-in Function} {} drawnow (@var{term}, @var{file}, 
@var{mono}, @var{debug_file})\n\
5780 Update figure windows and their children.  The event queue is flushed 
and\n\
5781 any callbacks generated are executed.  With the optional argument\n\
5782 @code{\"expose\"}, only graphic objects are updated and no other events 
or\n\
5783 callbacks are processed.\n\
5784 The third calling form of @code{drawnow} is for debugging and is\n\
5785 undocumented.\n\
5786 @end deftypefn")
5787 {
5788   static int drawnow_executing = 0;
5789   static bool __go_close_all_registered__ = false;
5790 
5791   octave_value retval;
5792 
5793   gh_manager::lock ();
5794 
5795   unwind_protect frame;
5796   frame.protect_var (Vdrawnow_requested, false);
5797 
5798   frame.protect_var (drawnow_executing);
5799 
5800   if (++drawnow_executing <= 1)
5801     {
5802       if (! __go_close_all_registered__)
5803         {
5804           octave_add_atexit_function ("__go_close_all__");
5805 
5806           __go_close_all_registered__ = true;
5807         }

The function __go_close_all__ is trivial

        function __go_close_all__ ()
          close ("all", "hidden");
        endfunction

As a simple check, I added `disp ("__go_close_all__")' to the end of 
__go_close_all__.m

When I try ...

        plot (1:10)
        print test.pdf

... there is no indication that __go_close_all__ is called.

My understanding is that the function octave_add_atexit_function, registers 
"__go_close_all__" to be called when Octave exits. Additional functions may be 
registered using `atexit ("foobar")' from the command line. I created a 
function ...

        function foobar ()
          disp ("Bye World")
          pause ()
        endfunction

.... then entered the command `atexit ("foobar")'. When I exit octave I get 
"__go_close_all__", and "Bye World", with the pause.

When I use the print function ...

        close all
        backend fltk
        plot (1:10)
        print test.pdf

... I get neither "__go_close_all__" or "Bye World" (I do get a correct 
test.pdf).

Dimitri / Michael,

If you add `'disp("__go_close_all__")'  to __go_close_all__, create the my 
foobar.m function add type `atexit ("foobar")' at the command line, what 
happens when you ...

        close all
        backend fltk
        plot (1:10)
        print test.pdf

Ben