--- loncom/interface/lonnavmaps.pm	2017/08/21 21:29:56	1.533
+++ loncom/interface/lonnavmaps.pm	2017/09/10 00:11:27	1.535
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Navigate Maps Handler
 #
-# $Id: lonnavmaps.pm,v 1.533 2017/08/21 21:29:56 raeburn Exp $
+# $Id: lonnavmaps.pm,v 1.535 2017/09/10 00:11:27 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -501,7 +501,7 @@ use Apache::lonlocal;
 use Apache::lonnet;
 use Apache::lonmap;
 
-use POSIX qw (floor strftime);
+use POSIX qw (ceil floor strftime);
 use Time::HiRes qw( gettimeofday tv_interval );
 use LONCAPA;
 use DateTime();
@@ -2882,40 +2882,89 @@ sub recurseup_maps {
 }
 
 sub recursed_crumbs {
-    my ($self,$mapurl) = @_;
+    my ($self,$mapurl,$restitle) = @_;
     my (@revmapinfo,@revmapres);
     my $mapres = $self->getResourceByUrl($mapurl);
     if (ref($mapres)) {
-        @revmapres = map { $self->getByMapPc($_); } split(/,/,$mapres->map_hierarchy());
+        @revmapres = map { $self->getByMapPc($_); } split(/,/,$mapres->map_breadcrumbs());
         shift(@revmapres);
-        push(@revmapres,$mapres);
     }
-    my %toplevel;
+    my $allowedlength = 60;
+    my $minlength = 5;
+    my $allowedtitle = 30;
+    if (($env{'environment.icons'} eq 'iconsonly') && (!$env{'browser.mobile'})) {
+        $allowedlength = 100;
+        $allowedtitle = 70;
+    }
+    if (length($restitle) > $allowedtitle) {
+        $restitle = &truncate_crumb_text($restitle,$allowedtitle);
+    }
+    my $totallength = length($restitle);
+    my @links;
+
     foreach my $map (@revmapres) {
         my $pc = $map->map_pc();
         next if ((!$pc) || ($pc == 1));
-        my $func = sub { return ($_[0]->src() ne $map->src); };
-        my @resources = $self->retrieveResources($map->src,$func,0);
-        my $count = 0;
-        my $notmap = 0;
-        foreach my $res (@resources) {
-            next unless (ref($res));
-            my $symb = $res->symb();
-            unless ($toplevel{$symb}) {
-                $toplevel{$symb} = $res->src;
-                $count ++;
-                unless ($res->is_map()) {
-                    $notmap ++;
+        push(@links,$map);
+        push(@revmapinfo,{'href' => $map->link().'?navmap=1','text' => $map->title(),'no_mt' => 1,});
+        $totallength += length($map->title());
+    }
+    my $numlinks = scalar(@links);
+    if ($numlinks) {
+        if ($totallength - $allowedlength > 0) {
+            my $available = $allowedlength - length($restitle);
+            my $avg = POSIX::ceil($available/$numlinks);
+            if ($avg < $minlength) {
+                $avg = $minlength;
+            }
+            @revmapinfo = ();
+            foreach my $map (@links) {
+                my $showntitle = &truncate_crumb_text($map->title(),$avg);
+                if ($showntitle ne '') {
+                    push(@revmapinfo,{'href' => $map->link().'?navmap=1','text' => $showntitle,'no_mt' => 1,});
                 }
             }
         }
-        if (($count > 1) || ($count && $notmap)) {
-             push(@revmapinfo,{'href' => $map->link().'?navmap=1','text' => $map->title(),'no_mt' => 1,});
-        }
+    }
+    if ($restitle ne '') {
+        push(@revmapinfo,{'text' => $restitle, 'no_mt' => 1});
     }
     return @revmapinfo;
 }
 
+sub truncate_crumb_text {
+    my ($title,$limit) = @_;
+    my $showntitle = '';
+    if (length($title) > $limit) {
+        my @words = split(/\b\s*/,$title);
+        if (@words == 1) {
+            $showntitle = substr($title,0,$limit).' ...';
+        } else {
+            my $linklength = 0;
+            my $num = 0;
+            foreach my $word (@words) {
+                $linklength += 1+length($word);
+                if ($word eq '-') {
+                    $showntitle =~ s/ $//;
+                    $showntitle .= $word;
+                } elsif ($linklength > $limit) {
+                    if ($num < @words) {
+                        $showntitle .= $word.' ...';
+                        last;
+                    } else {
+                        $showntitle .= $word;
+                    }
+                } else {
+                    $showntitle .= $word.' ';
+                }
+            }
+            $showntitle =~ s/ $//;
+        }
+        return $showntitle;
+    } else {
+        return $title;
+    }
+}
 
 #
 #  Determines the open/close dates for printing a map that
@@ -4564,6 +4613,12 @@ Returns a string with a comma-separated
 for the hierarchy of maps containing a map, with the top level
 map first, then descending to deeper levels, with the enclosing map last.
 
+=item * B<map_breadcrumbs>:
+
+Same as map_hierarchy, except maps containing only a single itemm if
+it's a map, or containing no items are omitted, unless it's the top
+level map (map_pc = 1), which is always included.
+
 =back
 
 =cut
@@ -4599,6 +4654,11 @@ sub map_hierarchy {
     my $pc = $self->map_pc();
     return $self->navHash("map_hierarchy_$pc", 0);
 }
+sub map_breadcrumbs {
+    my $self = shift;
+    my $pc = $self->map_pc();
+    return $self->navHash("map_breadcrumbs_$pc", 0);
+}
 
 #####
 # Property queries
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>500 Internal Server Error</title>
</head><body>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error or
misconfiguration and was unable to complete
your request.</p>
<p>Please contact the server administrator at 
 root@localhost to inform them of the time this error occurred,
 and the actions you performed just before this error.</p>
<p>More information about this error may be available
in the server error log.</p>
</body></html>