Support TeX elements in FreeType renderer. * libinterp/corefcn/txt-eng.cc: New file. Contains mapping from symbol name to character code, in Unicode and MS symbol. * libinterp/corefcn/modules.mk (COREFCN_SRC): Add txt-eng.cc. * libinterp/corefcn/oct-tex-lexer.ll: Add "\n" to rules applicable to ".", as the latter does not include new line characters. * libinterp/corefcn/oct-tex-parser.yy: Remove debug statements. * libinterp/corefcn/txt-eng.ft.cc (gripe_missing_glyph, gripe_glyph_render): Change signature from char to FT_ULong. (ft_render::ft_render): Adapt to new/removed members. (ft_render::~ft_render): Remove use of fonts member. (ft_render::set_font): Likewise. Use font instead. (ft_render::push_new_line): Likewise. Change meaning of yoffset and initialize line_yoffset. (ft_render::update_line_bbox): New method. (ft_render::set_mode): Change meaning of yoffset and initialize line_yoffset. (ft_render::process_character): New method. (ft_render::visit(text_element_string)): Use it. (ft_render::visit(text_element_list), ft_render::visit(text_element_subscript), ft_render::visit(text_element_superscript), ft_render::visit(text_element_color), ft_render::visit(text_element_fontsize), ft_render::visit(text_element_fontname), ft_render::visit(text_element_fontstyle), ft_render::visit(text_element_symbol)): New methods. (ft_render::set_color): Use color member instead of red/green/blue. * libinterp/corefcn/txt-eng-ft.h (ft_render::visit(text_element_list), ft_render::visit(text_element_subscript), ft_render::visit(text_element_superscript), ft_render::visit(text_element_color), ft_render::visit(text_element_fontsize), ft_render::visit(text_element_fontname), ft_render::visit(text_element_fontstyle), ft_render::visit(text_element_symbol)): New methods. (ft_render::update_line_bbox, ft_render::process_character): New methods. (ft_render::current_face): Removed method.i (ft_render::font): New member, replaces obsolete ft_render::fonts. (ft_render::line_yoffset): New member. (ft_render::color): New member, replaces obsolete red, green and blue. (ft_render::ft_font::ft_font()): Implement default constructor. (ft_render::ft_font::operator=): Fix incorrect use of FT_Reference_Face return value. (ft_render::ft_font::is_valid): New method. * libinterp/corefcn/txt-eng.h (class text_element_symbol, class text_element_fontname, class text_element_fontsize, class text_element_fontname, class text_element_fontstyle, class text_element_color): Add forward definition. (text_element_symbol::invalid_code): New enum. (text_element_symbol::code): New member. (text_element_symbol::text_element_symbol): Initialize it. (text_element_symbol::get_symbol_code): New method. (text_element_fontstyle::get_fontstyle): New method. (text_element_fontname::get_fontname): Renamed from fontname. (text_element_fontsize::get_fontsize): Renamed from fontsize.

## Copyright (C) 2012 Rik Wehbring
## Parts Copyright (C) 2012 Philip Nienhuis
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3 of the License, or (at
## your option) any later version.
##
## Octave is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} usejava (@var{feature})
## Return true if the Java element @var{feature} is available.
##
## Possible features are:
##
## @table @asis
## @item "awt"
## Abstract Window Toolkit for GUIs.
##
## @item "desktop"
## Interactive desktop is running.
##
## @item "jvm"
## Java Virtual Machine.
##
## @item "swing"
## Swing components for lightweight GUIs.
## @end table
##
## @code{usejava} determines if specific Java features are available in an
## Octave session.  This function is provided for scripts which may alter
## their behavior based on the availability of Java.  The feature "desktop"
## always returns @code{false} as Octave has no Java-based desktop.  Other
## features may be available if Octave was compiled with the Java Interface
## and Java is installed.
## @end deftypefn

## Author: Rik Wehbring
## Author: Philip Nienhuis <prnienhuis@users.sf.net>

function retval = usejava (feature)

  if (nargin != 1 || ! ischar (feature))
    print_usage ();
  endif

  retval = false;

  switch feature
    ## For each feature, try methods() on a Java class of a feature
    case "awt"
      try
        dum = methods ("java.awt.Frame");
        retval = true;
      end_try_catch
    case "desktop"
      ## Octave has no Java based GUI/desktop, leave retval = false
    case "jvm"
      try
        dum = methods ("java.lang.Runtime");
        retval = true;
      end_try_catch
    case "swing"
      try
        dum = methods ("javax.swing.Popup");
        retval = true;
      end_try_catch
    otherwise
      error ("usejava: unrecognized feature '%s'", feature);
  endswitch

endfunction


%!assert (usejava ("desktop"), false)

%!testif HAVE_JAVA
%! assert (usejava ("jvm"), true);

%% Test input validation
%!error usejava ()
%!error usejava (1, 2)
%!error usejava (1)
%!error <unrecognized feature> usejava ("abc")