--- loncom/homework/functionplotresponse.pm	2012/02/28 15:46:55	1.92
+++ 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 1.92 2012/02/28 15:46:55 www Exp $
+# $Id: functionplotresponse.pm,v 1.95 2012/02/29 01:46:52 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -38,6 +38,7 @@ BEGIN {
   &Apache::lonxml::register('Apache::functionplotresponse',('functionplotresponse','backgroundplot','spline',
                                                             'plotobject','plotvector',
                                                             'functionplotvectorrule','functionplotvectorsumrule',
+                                                            'drawvectorsum',
                                                             'functionplotcustomrule',
                                                             'functionplotrule','functionplotruleset',
                                                             'functionplotelements'));
@@ -550,6 +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; }
@@ -591,6 +596,95 @@ sub end_plotvector {
 }
 
 
+#
+# Vector sum - have GeoGebra draw a sum of specified vectors to help students draw
+#
+
+sub start_drawvectorsum {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result='';
+    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;
+    $label=ucfirst($label);
+    unless ($label) { $label="NewVector"; }
+    if ($target eq 'web') {
+        my ($xmin,$xmax,$ymin,$ymax)=&boundaries($parstack,$safeeval,-3);
+        unless (defined($tailx)) { $tailx=$xmin; }
+        unless (defined($taily)) { $taily=$ymin; }
+        unless (defined($vectorlist)) { $vectorlist=''; }
+        my @vectors=split(/\,/,$vectorlist);
+        if ($#vectors>0) {
+            my @sumx=();
+            my @sumy=();
+            foreach my $thisvector (@vectors) {
+                $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';
+                $result.=(<<ENDADDVEC);
+document.ggbApplet_$internalid.evalCommand("$vectorx=x($thisvector)");
+document.ggbApplet_$internalid.evalCommand("$vectory=y($thisvector)");
+document.ggbApplet_$internalid.evalCommand("Include$thisvector$label=Checkbox[]");
+ENDADDVEC
+                push(@sumx,"If[Include$thisvector$label,$vectorx,0]");
+                push(@sumy,"If[Include$thisvector$label,$vectory,0]");
+            }
+            $result.="document.ggbApplet_$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') {
+        $result=&Apache::edit::tag_start($target,$token,'Draw Vector Sum').
+             &Apache::edit::text_arg('Label on Plot:','label',
+                                     $token,'16').
+             &Apache::edit::text_arg('Tail x:','tailx',
+                                     $token,'8').
+             &Apache::edit::text_arg('Tail y:','taily',
+                                     $token,'8').
+             &Apache::edit::select_arg('Show Value:','showvalue',
+                                  ['yes','no'],$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','showvalue','vectorlist');
+        if ($constructtag) { $result=&Apache::edit::rebuild_tag($token); }
+    }
+    return $result;
+}
+
+
+sub end_drawvectorsum {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+    my $result='';
+    if ($target eq 'edit') {
+        $result=&Apache::edit::end_table();
+    }
+    return $result;
+}
+
+
 
 #
 # <backgroundplot function="..." fixed="yes/no" />
@@ -1218,6 +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;