--- loncom/xml/londefdef.pm	2005/07/10 21:43:35	1.278
+++ loncom/xml/londefdef.pm	2005/07/11 10:27:58	1.280
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Tags Default Definition Module 
 #
-# $Id: londefdef.pm,v 1.278 2005/07/10 21:43:35 www Exp $
+# $Id: londefdef.pm,v 1.280 2005/07/11 10:27:58 foxr Exp $
 # 
 #
 # Copyright Michigan State University Board of Trustees
@@ -563,7 +563,7 @@ EDITBUTTON
 
 sub end_body {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off unclosed <p>
+    my $currentstring = &end_p();	# Close off unclosed <p>
     if ($target eq 'web') {
 	$currentstring .= &Apache::lonxml::xmlend($target,$parser);
     } elsif ($target eq 'tex') {
@@ -575,7 +575,7 @@ sub end_body {
 #-- <center> tag (end tag required)
 sub start_center {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# Close off any prior para.
+    my $currentstring = &end_p();	# Close off any prior para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } elsif ($target eq 'tex') {
@@ -596,13 +596,15 @@ sub end_center {
 }
 
 #-- <b> tag (end tag required)
+#      NOTE: In TeX mode disables internal <p>
 sub start_b {
     my ($target,$token) = @_;
     my $currentstring = '';
     if ($target eq 'web') {
 	$currentstring = $token->[4];     
     } elsif ($target eq 'tex') {
-	$currentstring = '\textbf{';  
+	&disable_para();
+	$currentstring .= '\textbf{';  
     } 
     return $currentstring;
 }
@@ -613,18 +615,21 @@ sub end_b {
     if ($target eq 'web') {
 	$currentstring = $token->[2];     
     } elsif ($target eq 'tex') {
-	$currentstring = '}';  
+	&enable_para();
+	$currentstring = '}';
     } 
     return $currentstring;
 }
 
 #-- <strong> tag (end tag required)
+#    NOTE: in TeX mode disables internal <p>
 sub start_strong {
     my ($target,$token) = @_;
     my $currentstring = '';
     if ($target eq 'web') {
 	$currentstring = $token->[4];     
     } elsif ($target eq 'tex') {
+	&disable_para();
 	$currentstring = '\textbf{';  
     } 
     return $currentstring;
@@ -636,6 +641,7 @@ sub end_strong {
     if ($target eq 'web') {	
 	$currentstring = $token->[2];     
     } elsif ($target eq 'tex') {
+	&enable_para();
 	$currentstring = '}';  
     }
     return $currentstring;
@@ -644,7 +650,7 @@ sub end_strong {
 #-- <h1> tag (end tag required)
 sub start_h1 {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off any prior para.
+    my $currentstring = &end_p();	# Close off any prior para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -693,7 +699,7 @@ sub end_h1 {
 #-- <h2> tag
 sub start_h2 {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off any prior para.
+    my $currentstring = &end_p();	# Close off any prior para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -736,7 +742,7 @@ sub end_h2 {
 #-- <h3> tag
 sub start_h3 {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off any prior para.
+    my $currentstring = &end_p();	# Close off any prior para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -779,7 +785,7 @@ sub end_h3 {
 #-- <h4> tag
 sub start_h4 {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off any prior para.
+    my $currentstring = &end_p();	# Close off any prior para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -822,7 +828,7 @@ sub end_h4 {
 #-- <h5> tag
 sub start_h5 {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off any prior paras.
+    my $currentstring = &end_p();	# Close off any prior paras.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -865,7 +871,7 @@ sub end_h5 {
 #-- <h6> tag
 sub start_h6 {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off any prior paras.
+    my $currentstring = &end_p();	# Close off any prior paras.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -1123,15 +1129,34 @@ sub end_q {
 
     my $closing_string = '';		# String required to close <p>
 
+#   Some tags are <p> fragile meaning that <p> inside of them
+#   does not work within TeX mode.  This is managed via the 
+#   counter below:
+#
+
+    my $para_disabled = 0;
+
+sub disable_para {
+    $para_disabled++;
+}
+sub enable_para {
+    $para_disabled--;
+}
+
+
 #-- <p> tag (end tag optional)
 #optional attribute - align="center|left|right"
 sub start_p {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# close off prior para if in progress.
+    my $currentstring = '';
     if ($target eq 'web') {
+	$currentstring .= &end_p();	# close off prior para if in progress.
 	$currentstring .= $token->[4];
-	$closing_string = '</p>'; # Not sure this is correct.
-    } elsif ($target eq 'tex') {
+	if (! ($currentstring =~ /\//)) {
+	    $closing_string = '</p>'; # Deal correctly with <p /> e.g.
+	}
+    } elsif ($target eq 'tex' && !$para_disabled) {
+	$currentstring .= &end_p();	# close off prior para if in progress.
 	my $align=&Apache::lonxml::get_param('align',$parstack,$safeeval,undef,1);
 	if ($align eq 'center') {
 	    $currentstring .='\begin{center}\par';
@@ -1144,18 +1169,8 @@ sub start_p {
 	    $closing_string = '}\hfill}';
 	} else {
             $currentstring.='\par ';
-	    $closing_string = '\strut\\\\\strut';
+	    $closing_string = '\strut\\\\\strut ';
         }
-	my $signal=1;#<p> does not work inside <b>...</b> 
-	foreach my $tag (@$tagstack) {
-	    if (lc($tag) eq 'b') {
-		$signal=0;
-	    }
-	}
-	if (!$signal) {
-	    $currentstring = &end_p; # Just close the prior? Not sure this is correct
-	    $closing_string = '';    # Probably correct?
-	}
 
     }
     return $currentstring;
@@ -1164,9 +1179,16 @@ sub start_p {
 #  End paragraph processing just requires that we output the
 #  closing string that was saved and blank it.
 sub end_p {
-    my $current_string = $closing_string;
-    $closing_string = '';	# Not in a para anymore.
-    return $current_string;
+    #  Note only 'tex' mode uses disable_para and enable_para
+    #  so we don't need to know the target in the check below:
+
+    if (!$para_disabled) {
+	my $current_string = $closing_string;
+	$closing_string = '';	# Not in a para anymore.
+	return $current_string;
+    } else {
+	return '';
+    }
 
 }
 }
@@ -1415,7 +1437,7 @@ sub end_sup {
 #-- <hr> tag (end tag forbidden)
 sub start_hr {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# End enclosing para.
+    my $currentstring = &end_p();	# End enclosing para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -1453,12 +1475,44 @@ sub end_hr {
 }
 
 #-- <div> tag (end tag required)
+{
+
+#  Since div can be nested, the stack below is used
+#  in 'tex' mode to store the ending strings
+#  for the div stack.
+
+    my @div_end_stack;
+
 sub start_div {
-    my ($target,$token) = @_;
-    my $currentstring = &end_p;	# Close enclosing para.
+    my ($target,$token, $tagstack, $parstack, $parser, $safeeval) = @_;
+    my $currentstring = &end_p();	# Close enclosing para.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } 
+    if ($target eq 'tex') {
+	# 4 possible alignments: left, right, center, and -missing-.
+
+	my $endstring = '';
+
+	my $align = lc(&Apache::lonxml::get_param('align', $parstack,
+						  $safeeval, undef, 1));
+	if ($align eq 'center') {
+	    $currentstring .= '\begin{center}';
+	    $endstring      = '\end{center}';
+	}
+	elsif ($align eq 'right') {
+	    $currentstring .= '\begin{flushright}';
+	    $endstring     .= '\end{flushright}';
+	} elsif ($align eq 'left') {
+	    $currentstring .= '\begin{flushleft}';
+	    $endstring     = '\end{flushleft}';
+	} else {
+	
+	}
+	$currentstring .= "\n";   # For human readability.
+	$endstring       = "\n$endstring\n"; # For human readability
+	push(@div_end_stack, $endstring);
+    }
     return $currentstring;
 }
 
@@ -1467,9 +1521,14 @@ sub end_div {
     my $currentstring = '';
     if ($target eq 'web') {
 	$currentstring .= $token->[2];
-    } 
+    }
+    if ($target eq 'tex') {
+	my $endstring = pop @div_end_stack;
+	$currentstring .= $endstring;
+    }
     return $currentstring;
 }
+}
 
 #-- <a> tag (end tag required)
 sub start_a {
@@ -1537,7 +1596,7 @@ sub start_li {
 
 sub end_li {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# In case there's a <p> in the <li>
+    my $currentstring = &end_p();	# In case there's a <p> in the <li>
     if ($target eq 'web') {
 	$currentstring .= $token->[2];     
     } 
@@ -1573,7 +1632,7 @@ sub end_u {
 #-- <ul> tag (end tag required)
 sub start_ul {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close off enclosing list.
+    my $currentstring = &end_p();	# Close off enclosing list.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } elsif ($target eq 'tex') {
@@ -1640,7 +1699,7 @@ sub end_menu {
 #-- <dir> tag (end tag required)
 sub start_dir {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# In case there's a <p> prior to the list.
+    my $currentstring = &end_p();	# In case there's a <p> prior to the list.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } elsif ($target eq 'tex') {
@@ -1663,7 +1722,7 @@ sub end_dir {
 #-- <ol> tag (end tag required)
 sub start_ol {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# In case there's a <p> prior to the list.
+    my $currentstring = &end_p();	# In case there's a <p> prior to the list.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } elsif ($target eq 'tex') {
@@ -1717,7 +1776,7 @@ sub end_ol {
 #-- <dl> tag (end tag required)
 sub start_dl {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# In case there's a <p> unclosed prior to the list.
+    my $currentstring = &end_p();	# In case there's a <p> unclosed prior to the list.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } elsif ($target eq 'tex') {
@@ -1833,7 +1892,7 @@ sub end_dd {
 sub start_table {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
     my $textwidth = '';
-    my $currentstring = &end_p;
+    my $currentstring = &end_p();
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } elsif ($target eq 'tex') {
@@ -2153,7 +2212,7 @@ sub start_tr {
         
 sub end_tr {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close any pending <p> in the row.
+    my $currentstring = &end_p();	# Close any pending <p> in the row.
     if ($target eq 'web') {
 	$currentstring .= $token->[2];     
     } elsif ($target eq 'tex') {
@@ -2430,7 +2489,7 @@ sub end_th_tex {
 
 sub end_th {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# Close any open <p> in the row.
+    my $currentstring = &end_p();	# Close any open <p> in the row.
     if ($target eq 'web') {
 	$currentstring .= $token->[2];     
     } elsif ($target eq 'tex') {
@@ -2880,7 +2939,7 @@ sub end_xmp {
 #-- <pre> (end tag required)
 sub start_pre {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# close off pending <p>
+    my $currentstring = &end_p();	# close off pending <p>
     if ($target eq 'web') {
 	$currentstring .= $token->[4];
     } elsif ($target eq 'tex') {
@@ -2943,7 +3002,7 @@ sub end_externallink {
 #-- <blankspace heigth="">
 sub start_blankspace {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
-    my $currentstring = &end_p;	# closes off any unclosed <p>
+    my $currentstring = &end_p();	# closes off any unclosed <p>
     if ($target eq 'tex') {
 	my $howmuch = &Apache::lonxml::get_param('heigth',$parstack,$safeeval,undef,1);
 	$currentstring .= '\vskip '.$howmuch.' ';
@@ -3096,7 +3155,7 @@ sub end_blink {
 #-- <blockquote> tag (end tag required)
 sub start_blockquote {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# Close any unclosed <p>
+    my $currentstring = &end_p();	# Close any unclosed <p>
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } 
@@ -3419,7 +3478,7 @@ sub end_marquee {
 #-- <multicol> tag (end tag required)
 sub start_multicol {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# Close any pending <p>
+    my $currentstring = &end_p();	# Close any pending <p>
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     } 
@@ -3617,7 +3676,7 @@ sub end_server {
 #-- <spacer> tag (end tag forbidden)
 sub start_spacer {
     my ($target,$token) = @_;
-    my $currentstring = &end_p;	# Close off any open <p> tag.
+    my $currentstring = &end_p();	# Close off any open <p> tag.
     if ($target eq 'web') {
 	$currentstring .= $token->[4];     
     }