--- loncom/xml/lontexconvert.pm	2013/09/22 02:04:31	1.112.2.3
+++ loncom/xml/lontexconvert.pm	2016/08/05 21:04:25	1.112.2.5
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.112.2.3 2013/09/22 02:04:31 raeburn Exp $
+# $Id: lontexconvert.pm,v 1.112.2.5 2016/08/05 21:04:25 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -54,17 +54,37 @@ use IO::Socket::INET;
 #
 # Table of substitutions to unicode characters.
 #
+
+my %unicode_harpoons = (
+                        '\rightleftharpoons'  => 0x21cc,
+                      );
+
 my %unicode_translations = (
-    '\rightleftharpoons'  => 0x21cc,
 
-# Brackets - unicode is commented out with pure 8-bit ascii ugliness while we need it.
+# Brackets - unicode for browsers/OS which support it.
+
+    ''             => 0x23a1,
+    ''             => 0x23a2,
+    ''             => 0x23a3,
+    ''             => 0x23a4,
+    ''             => 0x23a5,
+    ''             => 0x23a6,
+
+#  Parens - unicode for browsers/OS which support it
+
+    ''              => 0x239b,
+    ''              => 0x239c,
+    ''              => 0x239d,
+    ''              => 0x239e,
+    ''              => 0x239f,
+    ''              => 0x23a0,
+
+);
+
+my %ascii_8bit_translations = (
+
+# Brackets - pure 8-bit ascii ugliness for browsers/OS which can't handle unicode
 
-#    ''             => 0x23a1,
-#    ''             => 0x23a2,
-#    ''             => 0x23a3,   # when unicode catches up with browsers
-#    ''             => 0x23a4,   # use these instead of the cheesey brackets below
-#    ''             => 0x23a5,
-#    ''             => 0x23a6   
     ''              => 0x5b,
     ''              => 0x5b,    # '['
     ''              => 0x5b,
@@ -72,24 +92,14 @@ my %unicode_translations = (
     ''              => 0x5d,
     ''              => 0x5d,
 
-#  Parens..again the unicode is commented out with the 8-bit ascii ugliness
-#  turned on until browsers catch up with the unicode world.
-
-#    ''              => 0x239b,
-#    ''              => 0x239c,
-#    ''              => 0x239d,
-#    ''              => 0x239e,
-#    ''              => 0x239f,
-#    ''              => 0x23a0
+# Parens - pure 8-bit ascii ugliness for browsers/OS which can't handle unicode
 
     ''              => 0x28,
     ''              => 0x28,      # '('
     ''              => 0x28,
-
     ''              => 0x29,
     ''              => 0x29,      # '('
-    ''              => 0x29
-
+    ''              => 0x29,
 
 );
 
@@ -171,16 +181,33 @@ sub convert_real {
     &Apache::lonxml::end_alarm();
 
     #
-    #  Several strings produced by tth require
+    # Several strings produced by tth require
     # transliteration -> unicode equivalents to render reliably
-    # in browsers. %unicode_translations is a table of
-    # string->substitution which we now apply:
+    # in browsers. %unicode_translations and %unicode_harpoons are tables of
+    # string->substitution which we now apply. (%ascii_8bit_translations used
+    # instead for Windows XP and mobile devices.
+
+    my $use_ascii;
+    if ($env{'browser.os'} eq 'win') {
+        if (($env{'browser.osversion'}) && ($env{'browser.osversion'} < 6.0)) {
+            $use_ascii = 1;
+        }
+    }
+    if ($env{'browser.mobile'}) {
+        $use_ascii = 1;
+    }
 
     foreach my $pattern (keys(%unicode_translations)) {
 	my $unicode = $unicode_translations{$pattern};
+	if ($use_ascii) {
+	    $unicode = $ascii_8bit_translations{$pattern};
+	}
 	$xmlstring = &unicode_subst($xmlstring, $pattern, $unicode);
     }
 
+    foreach my $pattern (keys(%unicode_harpoons)) {
+        $xmlstring = &unicode_subst($xmlstring, $pattern, $unicode_harpoons{$pattern});
+    }
 
     return ($xmlstring,$errorstring);
 }
@@ -271,76 +298,35 @@ sub MathJax_converted {
     }
 }
 
-sub jsMath_converted {
-    my $texstring=shift;
-    my $tag='span';
-    if (&displaystyle($texstring)) { $tag='div'; }
-    &clean_out_math_mode($texstring);
-    return &jsMath_header().
-	'<'.$tag.' class="math">'.$$texstring.'</'.$tag.'>';
-}
-
-{
-    my @jsMath_sent_header;
-    sub jsMath_reset {
-	undef(@jsMath_sent_header);
-    }
-    sub jsMath_push {
-	push(@jsMath_sent_header,0);
-    }
-    sub jsMath_header {
-	if (!@jsMath_sent_header) {
-	    &Apache::lonnet::logthis("mismatched calls of jsMath_header and jsMath_process");
-	    return '';
-	}
-	return '' if $jsMath_sent_header[-1];
-	$jsMath_sent_header[-1]=1;
-	return
-            '<script type="text/javascript">
-                     function NoFontMessage () {}
-                     jsMath = {Parser: {prototype: {environments: {\'eqnarray*\' :[\'Array\',null,null,\'rcl\',[5/18,5/18],3,\'D\']}}}};
-                   </script>'."\n".
-	    '<script type="text/javascript" src="/adm/jsMath/jsMath.js"></script>'."\n";
-    }
-    sub jsMath_process {
-	my $state = pop(@jsMath_sent_header);
-	return '' if !$state;
-	return "\n".
-	    '<script type="text/javascript">jsMath.Process()</script>'."\n";
-    }
-    sub jsMath_state {
-	my ($level) = @_;
-	return $jsMath_sent_header[$level];
-    }
-}
-
 sub tex_engine {
     if (exists($env{'form.texengine'})) {
 	if ($env{'form.texengine'} ne '') {
+            if (lc($env{'form.texengine'}) eq 'jsmath') {
+                return 'MathJax';
+            }
             return $env{'form.texengine'};
         }
     }    
     if ($env{'request.course.id'}
 	&& exists($env{'course.'.$env{'request.course.id'}.'.texengine'})) {
+        if (lc($env{'course.'.$env{'request.course.id'}.'.texengine'}) eq 'jsmath') {
+            return 'MathJax';
+        }
 	return $env{'course.'.$env{'request.course.id'}.'.texengine'};
     }
     if (exists($env{'environment.texengine'})) {
+        if (lc($env{'environment.texengine'}) eq 'jsmath') {
+            return 'MathJax';
+        }
 	return $env{'environment.texengine'};
     }
     return 'tth';
 }
 
 sub init_math_support {
-    my ($inherit_jsmath) = @_;
     &init_tth();
-    &Apache::lontexconvert::jsMath_push();
-    if (lc(&tex_engine()) eq 'jsmath' ||
-	($inherit_jsmath && &jsMath_state(-2))) {
-	return &Apache::lontexconvert::jsMath_header();
-    }
     &Apache::lontexconvert::MathJax_push();
-    if (lc(&tex_engine()) eq 'mathjax') { # ||
-        #($inherit_jsmath && &jsMath_state(-2))) {
+    if (lc(&tex_engine()) eq 'mathjax') {
         return &Apache::lontexconvert::MathJax_header();
     }
     return;
@@ -402,7 +388,7 @@ sub converted {
     if ($mode =~ /tth/i) {
 	return &tth_converted($string);
     } elsif ($mode =~ /jsmath/i) {
-	return &jsMath_converted($string);
+	return &jMathJax_converted($string);
     } elsif ($mode =~ /mathjax/i) {
         return &MathJax_converted($string);
     } elsif ($mode =~ /mimetex/i) {
@@ -569,6 +555,8 @@ sub postprocess_algebra {
     $string =~s/\\lim\\left\((.+?),(.+?),(.+?)\\right\)/\\lim_{$2\\to $3}$1/gs;
     return $string;
 }
+
+
 1;
 __END__
 
@@ -611,10 +599,7 @@ Header
 =item displaystyle()
 
 
-=item jsMath_converted()
-
 =item MathJax_converted()
-        - Mimics the jsMath functionality
 
 =item tex_engine()