--- loncom/interface/lonmainmenu.pm	2013/04/17 01:30:15	1.10.2.1
+++ loncom/interface/lonmainmenu.pm	2025/03/25 01:02:59	1.14
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # displays the main menu
 #
-# $Id: lonmainmenu.pm,v 1.10.2.1 2013/04/17 01:30:15 raeburn Exp $
+# $Id: lonmainmenu.pm,v 1.14 2025/03/25 01:02:59 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -35,13 +35,23 @@
 package Apache::lonmainmenu;
 
 use strict;
-use Apache::Constants qw(:common);
+use Apache::Constants qw(:common REDIRECT);
 use Apache::loncommon();
 use Apache::lonnet;
 use Apache::lonmenu();
+use Apache::lonlocal;
 
 sub handler {
     my $r = shift;
+
+    # Check for critical messages and redirect if present.
+    my ($redirect,$url) = &Apache::loncommon::critical_redirect(300,'menu');
+    if ($redirect) {
+        &Apache::loncommon::content_type($r,'text/html');
+        $r->header_out(Location => $url);
+        return REDIRECT;
+    }
+
     &Apache::loncommon::no_cache($r);
     &Apache::loncommon::content_type($r,'text/html');
     $r->send_http_header;
@@ -51,12 +61,72 @@ sub handler {
 # temporarily set interface to "faketextual" and remote to "off", which renders
 # the main menu
     $env{'browser.interface'}='faketextual';
-    $env{'environment.remote'}='off';
-    $r->print(&Apache::loncommon::start_page( 'Main Menu',
-                                               undef,
-                                              {'bread_crumbs' => 1}));
-    $r->print(&Apache::lonmenu::inlinemenu());
-    $r->print(&Apache::loncommon::end_page());
+
+#
+# If menu collection is in effect in course context, determine if Main Menu
+# will be shown.
+#
+    my $showmenu = 1;
+    my $deeplinkmenu;
+    if ($env{'request.course.id'}) {
+        (my $menucoll,$deeplinkmenu,my $menuref) =
+            &Apache::loncommon::menucoll_in_effect();
+        if (($menucoll) && (ref($menuref) eq 'HASH')) {
+            if ($menuref->{'main'} eq 'n') {
+                $showmenu = 0;
+            }
+        }
+    }
+    my $js;
+    my $args = { 'bread_crumbs' => 1 };
+    if ($showmenu) {
+        $js = <<"END";
+<script type="text/javascript">
+// <![CDATA[
+function formatMenuText() {
+    var textArray = document.getElementsByClassName("LC_menu_text");
+    if (textArray.length > 0) {
+        var singleLineHeight = textArray[0].offsetHeight;
+        for (var i=1; i<textArray.length; i++) {
+            if (textArray[i].offsetHeight > singleLineHeight) {
+                var el = textArray[i].previousElementSibling;
+                el.style.cssFloat = "left";
+                el.style.marginRight = "5px";
+            }
+        }
+    }
+}
+// ]]>
+</script>
+END
+        $args->{'add_entries'} = { 'onload' => 'javascript:formatMenuText();' };
+    }
+
+    $r->print(&Apache::loncommon::start_page( 'Main Menu',$js,$args).
+              '<div class="LC_landmark" role="main">');
+#
+# If menu collection is in effect in course context, and Main Menu is 
+# not included, display message in place of usual menu items.
+#
+    unless ($showmenu) {
+        my $nomenumsg;
+        my $crstype = &Apache::loncommon::course_type();
+        if ($deeplinkmenu) {
+            $nomenumsg = &mt('Page unavailable');
+        } else {
+            $nomenumsg = &mt("Main Menu page is unavailable in this $crstype");
+        }
+        $r->print('<h1 class="LC_heading_3">'.$nomenumsg.'</h1>'.
+                  '</div>'.&Apache::loncommon::end_page());
+        return OK;
+    }
+#
+# A span with class of LC_menu_text needs to be first item with that class.
+# It will be used by formatMenuText() to determine the offsetHeight for a single line.
+#
+    $r->print('<span class="LC_menu_text">&nbsp;</span>'.
+              &Apache::lonmenu::inlinemenu().
+              '</div>'.&Apache::loncommon::end_page());
     return OK;
 }