--- loncom/homework/functionplotresponse.pm	2012/02/28 22:42:31	1.93
+++ loncom/homework/functionplotresponse.pm	2012/02/29 01:46:52	1.95
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # Functionplot responses
 #
-# $Id: functionplotresponse.pm,v 1.93 2012/02/28 22:42:31 www Exp $
+# $Id: functionplotresponse.pm,v 1.95 2012/02/29 01:46:52 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -551,6 +551,10 @@ sub start_plotvector {
    $label=~s/\W//gs;
    $label=ucfirst($label);
    unless ($label) { $label="NewVector"; }
+   if ($Apache::functionplotresponse::vectorlabels{$label}) {
+       &Apache::lonxml::warning(&mt('Vector labels must be unique: [_1]',$label));
+   }
+   $Apache::functionplotresponse::vectorlabels{$label}=1;
    if ($target eq 'web') {
       my ($xmin,$xmax,$ymin,$ymax)=&boundaries($parstack,$safeeval,-3);
       unless (defined($tailx)) { $tailx=$xmin; }
@@ -602,6 +606,7 @@ sub start_drawvectorsum {
     my $internalid = $Apache::inputtags::part.'_'.$Apache::inputtags::response[-1];
     my $tailx=&Apache::lonxml::get_param('tailx',$parstack,$safeeval);
     my $taily=&Apache::lonxml::get_param('taily',$parstack,$safeeval);
+    my $showvalue=&Apache::lonxml::get_param('showvalue',$parstack,$safeeval);
     my $vectorlist=&Apache::lonxml::get_param('vectorlist',$parstack,$safeeval);
     my $label=&Apache::lonxml::get_param('label',$parstack,$safeeval);
     $label=~s/\W//gs;
@@ -620,6 +625,10 @@ sub start_drawvectorsum {
                 $thisvector=~s/\W//gs;
                 $thisvector=ucfirst($thisvector);
                 unless ($thisvector) { next; }
+                unless ($Apache::functionplotresponse::vectorlabels{$thisvector}) {
+                    &Apache::lonxml::warning(&mt('Vectors must be defined before using them for drawing vector sums: [_1]',$thisvector));
+                    next;
+                }
                 my $vectorx=$thisvector.'X';
                 my $vectory=$thisvector.'Y';
                 $result.=(<<ENDADDVEC);
@@ -632,11 +641,16 @@ ENDADDVEC
             }
             $result.="document.ggbApplet_$internalid.evalCommand(".'"'."xTot$label=".join('+',@sumx).'");'."\n";
             $result.="document.ggbApplet_$internalid.evalCommand(".'"'."yTot$label=".join('+',@sumy).'");'."\n";
+            my $show=0;
+            if ($showvalue=~/yes/i) {
+                $show=1;
+            }
             $result.=(<<ENDMAKEVECTOR);
 document.ggbApplet_$internalid.evalCommand("$label=Vector[($tailx,$taily),($tailx+xTot$label,$taily+yTot$label)]");
 document.ggbApplet_$internalid.setLabelVisible("$label",true);
 document.ggbApplet_$internalid.setLineThickness("$label",8);
 document.ggbApplet_$internalid.setColor("$label",255,0,0);
+document.ggbApplet_$internalid.setLabelStyle("$label",VALUE=$show);
 ENDMAKEVECTOR
         }
     } elsif ($target eq 'edit') {
@@ -646,13 +660,15 @@ ENDMAKEVECTOR
              &Apache::edit::text_arg('Tail x:','tailx',
                                      $token,'8').
              &Apache::edit::text_arg('Tail y:','taily',
-                                     $token,'8').'<br />'.
+                                     $token,'8').
+             &Apache::edit::select_arg('Show Value:','showvalue',
+                                  ['yes','no'],$token).'<br />'.
              &Apache::edit::text_arg('Vector List:','vectorlist',
                                      $token,'40').
              &Apache::edit::end_row();
     } elsif ($target eq 'modified') {
         $env{'form.'.&Apache::edit::html_element_name('label')}=ucfirst($env{'form.'.&Apache::edit::html_element_name('label')});
-        my $constructtag=&Apache::edit::get_new_args($token,$parstack,$safeeval,'label','tailx','taily','vectorlist');
+        my $constructtag=&Apache::edit::get_new_args($token,$parstack,$safeeval,'label','tailx','taily','showvalue','vectorlist');
         if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
     }
     return $result;
@@ -1296,6 +1312,8 @@ sub start_functionplotresponse {
   undef %Apache::functionplotresponse::previous;
   $Apache::functionplotresponse::inputfields='';
   $Apache::functionplotresponse::counter=0;
+# Remember vectors
+  undef %Apache::functionplotresponse::vectorlabels;
 # Remember rules
   undef @Apache::functionplotresponse::functionplotrules;
   undef @Apache::functionplotresponse::functionplotvectorrules;