--- loncom/interface/lonnavmaps.pm	2002/11/08 20:58:13	1.101
+++ loncom/interface/lonnavmaps.pm	2002/11/14 16:51:03	1.105
@@ -2,7 +2,7 @@
 # The LearningOnline Network with CAPA
 # Navigate Maps Handler
 #
-# $Id: lonnavmaps.pm,v 1.101 2002/11/08 20:58:13 bowersj2 Exp $
+# $Id: lonnavmaps.pm,v 1.105 2002/11/14 16:51:03 bowersj2 Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -37,15 +37,13 @@
 # 3/1/1,6/1,17/1,29/1,30/1,2/8,9/21,9/24,9/25 Gerd Kortemeyer
 # YEAR=2002
 # 1/1 Gerd Kortemeyer
-#
+# Oct-Nov Jeremy Bowers
 
 package Apache::lonnavmaps;
 
 use strict;
 use Apache::Constants qw(:common :http);
-use Apache::lonnet();
 use Apache::loncommon();
-use GDBM_File;
 use POSIX qw (floor strftime);
 
 sub handler {
@@ -1355,7 +1353,7 @@ sub new {
                 my $resultingVal = $curRes->{DATA}->{$valName};
                 my $nextResources = $curRes->$nextResourceMethod();
                 my $resourceCount = scalar(@{$nextResources});
-            
+
                 if ($resourceCount == 1) {
                     my $current = $nextResources->[0]->{DATA}->{$valName} || 999999999;
                     $nextResources->[0]->{DATA}->{$valName} = min($resultingVal, $current);
@@ -1441,7 +1439,7 @@ sub next {
     my $here;
     while ( $i >= 0 && !$found ) {
         if ( scalar(@{$self->{STACK}->[$i]}) > 0 ) {
-            $here = $self->{HERE} = shift @{$self->{STACK}->[$i]};
+            $here = pop @{$self->{STACK}->[$i]};
             $found = 1;
             $newDepth = $i;
         }
@@ -1459,6 +1457,18 @@ sub next {
         }
     }
 
+    # If this is not a resource, it must be an END_BRANCH marker we want
+    # to return directly.
+    if (!ref($here)) {
+        if ($here == END_BRANCH()) { # paranoia, in case of later extension
+            $self->{CURRENT_DEPTH}--;
+            return $here;
+        }
+    }
+
+    # Otherwise, it is a resource and it's safe to store in $self->{HERE}
+    $self->{HERE} = $here;
+
     # Get to the right level
     if ( $self->{CURRENT_DEPTH} > $newDepth ) {
         push @{$self->{STACK}->[$newDepth]}, $here;
@@ -1478,14 +1488,29 @@ sub next {
     # So we need to look at all the resources we can get to from here,
     # categorize them if we haven't seen them, remember if we have a new
     my $nextUnfiltered = $here->getNext();
-
+    my $maxDepthAdded = -1;
+    
     for (@$nextUnfiltered) {
         if (!defined($self->{ALREADY_SEEN}->{$_->{ID}})) {
-            push @{$self->{STACK}->[$_->{DATA}->{DISPLAY_DEPTH}]}, $_;
+            my $depth = $_->{DATA}->{DISPLAY_DEPTH};
+            push @{$self->{STACK}->[$depth]}, $_;
             $self->{ALREADY_SEEN}->{$_->{ID}} = 1;
+            if ($maxDepthAdded < $depth) { $maxDepthAdded = $depth; }
         }
     }
-    
+
+    # Is this the end of a branch? If so, all of the resources examined above
+    # led to lower levels then the one we are currently at, so we push a END_BRANCH
+    # marker onto the stack so we don't forget.
+    # Example: For the usual A(BC)(DE)F case, when the iterator goes down the
+    # BC branch and gets to C, it will see F as the only next resource, but it's
+    # one level lower. Thus, this is the end of the branch, since there are no
+    # more resources added to this level or above.
+    my $isEndOfBranch = $maxDepthAdded < $self->{CURRENT_DEPTH};
+    if ($isEndOfBranch) {
+        push @{$self->{STACK}->[$self->{CURRENT_DEPTH}]}, END_BRANCH();
+    }
+
     # That ends the main iterator logic. Now, do we want to recurse
     # down this map (if this resource is a map)?
     if ($self->{HERE}->is_map() &&
@@ -2414,7 +2439,7 @@ sub getNext {
         # Don't remember it if the student doesn't have browse priviledges
         # future note: this may properly belong in the client of the resource
         my $browsePriv = &Apache::lonnet::allowed('bre', $self->src);
-        if ($browsePriv ne '2' && $browsePriv ne 'F') {
+        if (!($browsePriv ne '2' && $browsePriv ne 'F')) {
             push @branches, $next;
         }
     }
@@ -2433,7 +2458,7 @@ sub getPrevious {
         # Don't remember it if the student doesn't have browse priviledges
         # future note: this may properly belong in the client of the resource
         my $browsePriv = &Apache::lonnet::allowed('bre', $self->src);
-        if ($browsePriv ne '2' && $browsePriv ne 'F') {
+        if (!($browsePriv ne '2' && $browsePriv ne 'F')) {
             push @branches, $prev;
         }
     }