--- loncom/xml/londefdef.pm	2016/08/13 20:01:52	1.456.2.2
+++ loncom/xml/londefdef.pm	2020/09/10 00:28:48	1.465
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Tags Default Definition Module 
 #
-# $Id: londefdef.pm,v 1.456.2.2 2016/08/13 20:01:52 raeburn Exp $
+# $Id: londefdef.pm,v 1.465 2020/09/10 00:28:48 raeburn Exp $
 # 
 #
 # Copyright Michigan State University Board of Trustees
@@ -92,6 +92,14 @@ sub start_m {
     my $inside = &Apache::lonxml::get_all_text_unbalanced("/m",$parser);
     if ($target eq 'web' || $target eq 'analyze') {
 	&Apache::lonxml::debug("M is starting with:$inside:");
+        if (!($inside =~ /^\s*\$.*\$\s*$/ || $inside =~ /^\s*\\[([].*\\[)\]]\s*$/)) {
+            # Non-math LaTeX will not be rendered correctly with MathJax
+            # and it should be avoided anyway.
+            # On top of that, MathJax will render math without $, but
+            # it will fail with tth. This is worth a warning.
+            # (even though some people might just use latex for printing)
+            &Apache::lonxml::warning(&mt('Missing $ in [_1].','<m>'));
+        }
 	my $eval=&Apache::lonxml::get_param('eval',$parstack,$safeeval);
 	if ($eval eq 'on') {
 	    $inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
@@ -638,6 +646,12 @@ sub edit_controls {
     }
     $result .= '
 <div><input type="submit" name="editmode" accesskey="e" value="'.&mt('Edit').'" />';
+    if ($env{'browser.type'} ne 'explorer' || $env{'browser.version'} > 9) {
+        my $uri = $env{'request.uri'};
+        my $daxeurl = '/daxepage'.$uri;
+        $result .= '<input type="button" value="'.&mt('Edit with Daxe').'" '.
+                  'onclick="window.open(\''.$daxeurl.'\',\'_blank\');" />';
+    }
     if (($env{'request.course.id'}) && ($env{'form.forceedit'})) {
         my $url=&Apache::lonnet::hreflocation('',$env{'request.filename'});
         if ($url =~ /\.html?$/i) {
@@ -812,7 +826,7 @@ sub end_h1 {
 	$currentstring .= $token->[2];
     } elsif ($target eq 'tex') {
 	my $post='\vskip 0 mm ';
-	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
+	my $align=lc(&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1));
 	if ($align eq 'center') {
 	    $post='\end{center}';
 	} elsif ($align eq 'left') {
@@ -1291,6 +1305,10 @@ sub start_p {
 
 	$currentstring .= &end_p();	# close off prior para if in progress.
 	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
+	if (!defined $align) {
+          # check inline CSS
+          $align = &get_css_property('text-align',$parstack,$safeeval);
+        }
 	if ($align eq 'center') {
 	    $currentstring .='\begin{center}\par ';
 	    $closing_string = '\end{center}';
@@ -1298,13 +1316,13 @@ sub start_p {
 		$currentstring = &center_correction().$currentstring;
 	    }
 	} elsif ($align eq 'right') {
-	    $currentstring.="\n".'{\flushright ';
+	    $currentstring.="\n".'\begin{flushright}';
 #	    $currentstring.='\makebox['.$env{'form.textwidth'}.']{\hfill\llap{';
-	    $closing_string= "}\n";
+	    $closing_string= '\end{flushright}'."\n";
 	} elsif ($align eq 'left') {
-	    $currentstring.= "\n".'{\flushleft ';
+	    $currentstring.= "\n".'\begin{flushleft}';
 #	    $currentstring.='\noindent\makebox['.$env{'form.textwidth'}.']{{';
-	    $closing_string = "}\n";
+	    $closing_string = '\end{flushleft}'."\n";
 	} else {
             $currentstring.='\par ';
 	    if (&is_inside_of($tagstack, 'table')) {
@@ -2858,8 +2876,8 @@ sub start_img {
         my $only = join(',',&Apache::loncommon::filecategorytypes('Pictures'));
 	$currentstring .=&Apache::edit::tag_start($target,$token);
 	$currentstring .=&Apache::edit::text_arg('Image Url:','src',$token,70).
-	    &Apache::edit::browse('src',undef,'alt',$only).' '.
-	    &Apache::edit::search('src',undef,'alt').'<br />';
+                         &Apache::edit::browse_or_search('src',undef,'alt',$only,undef,1).
+                         '<br />';
 	$currentstring .=&Apache::edit::text_arg('Description:','alt',$token,70).'<br />';
 	$currentstring .=&Apache::edit::text_arg('width (pixel):','width',$token,5);
 	$currentstring .=&Apache::edit::text_arg('height (pixel):','height',$token,5).'<br />';
@@ -2881,17 +2899,19 @@ sub start_img {
 	my $src=    &Apache::lonxml::get_param('src',$parstack,$safeeval);
 	my $width=  &Apache::lonxml::get_param('width',$parstack,$safeeval);
 	my $height= &Apache::lonxml::get_param('height',$parstack,$safeeval);
-
+        my $element = &Apache::edit::get_element('src'); 
+        my $text;
         if ($token->[2]{'src'}=~/\$/) {
-           $currentstring.=&mt('Variable image source');
+           $text = &mt('Variable image source');
         } elsif ($token->[2]{'src'}=~/\S/) {
 	   $currentstring .= '<img src="'.$src.'" alt="'.$alt.'" ';
 	   if ($width) { $currentstring.=' width="'.$width.'" '; }
 	   if ($height) { $currentstring.=' height="'.$height.'" '; }
-	   $currentstring .= ' />';
+	   $currentstring .= ' id="previewimg_'.$element.'" />';
         } else {
-           $currentstring.=&mt("No image source specified");
+           $text = &mt("No image source specified");
         }
+        $currentstring .= ' <span id="showimg_'.$element.'">'.$text.'</span>';
     } elsif ($target eq 'modified') {
 	my ($osrc,$owidth,$oheight)=
 	    ($token->[2]{'src'},$token->[2]{'width'},$token->[2]{'height'});
@@ -4037,13 +4057,33 @@ sub end_spacer {
     return $currentstring;
 }
 
+my @span_end_stack; # for span tex target
+
 #-- <span> tag (end tag required)
 sub start_span {
-    my ($target,$token) = @_;
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
     my $currentstring = '';
     if ($target eq 'web' || $target eq 'webgrade') {
 	$currentstring = $token->[4];     
-    } 
+    } elsif ($target eq 'tex') {
+        my $endstring = '';
+        my $family = &get_css_property('font-family',$parstack,$safeeval);
+        if ($family eq 'monospace') {
+            $currentstring .= '\texttt{';
+            $endstring .= '}';
+        }
+        my $weight = &get_css_property('font-weight',$parstack,$safeeval);
+        if ($weight eq 'bold') {
+            $currentstring .= '\textbf{';
+            $endstring .= '}';
+        }
+        my $style = &get_css_property('font-style',$parstack,$safeeval);
+        if ($style eq 'italic') {
+            $currentstring .= '\textit{';
+            $endstring .= '}';
+        }
+        push(@span_end_stack, $endstring);
+    }
     return $currentstring;
 }
 
@@ -4052,7 +4092,10 @@ sub end_span {
     my $currentstring = '';
     if ($target eq 'web' || $target eq 'webgrade') {
 	$currentstring = $token->[2];    
-    } 
+    } elsif ($target eq 'tex') {
+        my $endstring = pop @span_end_stack;
+        $currentstring .= $endstring;
+    }
     return $currentstring;
 }
 
@@ -4650,6 +4693,23 @@ sub clean_docs_httpref {
     return $cleanhref;
 }
 
+# This is retrieving a CSS property from the style attribute of the current element.
+# It is not checking <style> elements or linked stylesheets yet.
+sub get_css_property {
+    my ($property,$parstack,$safeeval) = @_;
+    my $style=&Apache::lonxml::get_param('style',$parstack,$safeeval,undef,1);
+    my @style_components=split(/;/,$style);
+    foreach my $css_pair (@style_components) {
+        my ($name, $value) = split(/:/, $css_pair);
+        $name =~ s/^\s+|\s+$//g;
+        $value =~ s/^\s+|\s+$//g;
+        if ($name eq $property) {
+            return $value;
+        }
+    }
+    return undef;
+}
+
 =pod
 
 =head1 NAME