--- loncom/xml/lontexconvert.pm	2012/05/10 19:19:30	1.112.2.1
+++ loncom/xml/lontexconvert.pm	2016/02/20 00:12:45	1.118
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # TeX Conversion Module
 #
-# $Id: lontexconvert.pm,v 1.112.2.1 2012/05/10 19:19:30 raeburn Exp $
+# $Id: lontexconvert.pm,v 1.118 2016/02/20 00:12:45 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,
 
 );
 
@@ -168,19 +178,37 @@ sub convert_real {
     $xmlstring=~s/^\s*\<br clear\=\"all\"/\<br/s;
     $xmlstring=~s/^\s*//;
     $xmlstring=~s/\s*$//;
+    $xmlstring=~s/^<br \/><table/<table/;
     &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);
 }
@@ -241,72 +269,76 @@ sub displaystyle {
     return 0;
 }
 
-sub jsMath_converted {
+sub MathJax_converted {
     my $texstring=shift;
-    my $tag='span';
-    if (&displaystyle($texstring)) { $tag='div'; }
+    my $tag='math/tex;';
+    if (&displaystyle($texstring)) { $tag='math/tex; mode=display'; }
     &clean_out_math_mode($texstring);
-    return &jsMath_header().
-	'<'.$tag.' class="math">'.$$texstring.'</'.$tag.'>';
+    return &MathJax_header().
+      '<script type="'.$tag.'">'.$$texstring.'</script>';
 }
 
 {
-    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];
-    }
+    #Relies heavily on the previous jsMath installation
+    my @MathJax_sent_header;
+    sub MathJax_reset {
+        undef(@MathJax_sent_header);
+    }
+    sub MathJax_push {
+        push(@MathJax_sent_header,0);
+    }
+    sub MathJax_header {
+        if (!@MathJax_sent_header) {
+            &Apache::lonnet::logthis("mismatched calls of MathJax_header and MathJax_process");
+            return '';
+        }
+        return '' if $MathJax_sent_header[-1];
+        $MathJax_sent_header[-1]=1;
+        return
+          '<script type="text/javascript" src="/adm/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>'."\n";
+    }
+    #sub MathJax_process {
+    #    my $state = pop(@MathJax_sent_header);
+    #    return '' if !$state;
+    #    return "\n".
+    #        '<script type="text/javascript">MathJax.Process()</script>'."\n";
+    #}
+    #sub MathJax_state {
+    #    my ($level) = @_;
+    #    return $MathJax_sent_header[$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') {
+        return &Apache::lontexconvert::MathJax_header();
     }
     return;
 }
@@ -367,7 +399,9 @@ sub converted {
     if ($mode =~ /tth/i) {
 	return &tth_converted($string);
     } elsif ($mode =~ /jsmath/i) {
-	return &jsMath_converted($string);
+        return &MathJax_converted($string);
+    } elsif ($mode =~ /mathjax/i) {
+	return &MathJax_converted($string);
     } elsif ($mode =~ /mimetex/i) {
 	return &mimetex_converted($string);
     } elsif ($mode =~ /raw/i) {
@@ -447,7 +481,7 @@ sub msgtexconverted {
     foreach my $fragment (split(/(?:\&lt\;|\<)\/*algebra\s*(?:\&gt\;|\>)/i,
 				$message)) {
 	if ($tex) {
-        my $algebra = &algebra($fragment, 'web', undef, undef, undef, undef, 'tth');
+        my $algebra = &algebra($fragment, 'web', undef, undef, undef, 'tth');
 	    if ($email) {
 		$outmessage.='</pre><tt>'.$algebra.'</tt><pre>';
 		$tex=0;
@@ -532,6 +566,8 @@ sub postprocess_algebra {
     $string =~s/\\lim\\left\((.+?),(.+?),(.+?)\\right\)/\\lim_{$2\\to $3}$1/gs;
     return $string;
 }
+
+
 1;
 __END__
 
@@ -574,11 +610,10 @@ Header
 =item displaystyle()
 
 
-=item jsMath_converted()
+=item MathJax_converted()
 
 =item tex_engine()
 
-
 =item init_math_support()
 
 =item mimetex_valign()