--- loncom/homework/functionplotresponse.pm	2010/10/04 18:28:53	1.3
+++ loncom/homework/functionplotresponse.pm	2010/10/04 19:26:39	1.4
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # option list style responses
 #
-# $Id: functionplotresponse.pm,v 1.3 2010/10/04 18:28:53 www Exp $
+# $Id: functionplotresponse.pm,v 1.4 2010/10/04 19:26:39 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -33,7 +33,7 @@ use Apache::lonlocal;
 use Apache::lonnet;
 
 BEGIN {
-  &Apache::lonxml::register('Apache::functionplotresponse',('functionplotresponse'));
+  &Apache::lonxml::register('Apache::functionplotresponse',('functionplotresponse','backgroundplot'));
 }
 
 sub geogebra_startcode {
@@ -103,10 +103,44 @@ sub start_init_script {
 <script type="text/javascript">
 // <![CDATA[
 function ggbInit_$id() {
-   alert("Hello $id");
 ENDSTARTINIT
 }
 
+sub axes_script {
+    my ($id,$xmin,$xmax,$ymin,$ymax,$xvisible,$yvisible,$gvisible)=@_;
+    return (<<ENDAXESSCRIPT);
+            // changes (xmin, xmax, ymin, ymax)
+            document.ggbApplet_$id.setCoordSystem($xmin,$xmax,$ymin,$ymax);
+
+            // makes the (x,y) axis (in)visible
+            document.ggbApplet_$id.setAxesVisible($xvisible,$yvisible);
+            // makes the grid (in)visible
+            document.ggbApplet_$id.setGridVisible($gvisible);
+ENDAXESSCRIPT
+}
+
+sub plot_script {
+   my ($id,$function)=@_;
+   return (<<ENDPLOTSCRIPT);
+            document.ggbApplet_$id.evalCommand("y=$function");
+ENDPLOTSCRIPT
+}
+
+sub start_backgroundplot {
+   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+   my $result='';
+   my $internalid = $Apache::inputtags::part.'_'.$Apache::inputtags::response[-1];
+   my $function=&Apache::lonxml::get_param('function',$parstack,$safeeval);
+   unless ($function) { $function="0"; }
+   if ($target eq 'web') {
+      $result.=&plot_script($internalid,$function);
+   }
+   return $result;
+}
+
+sub end_backgroundplot {
+}
+ 
 sub end_init_script {
     return (<<ENDENDINIT);
 }
@@ -120,16 +154,21 @@ sub start_functionplotresponse {
   my $result='';
   my $internalid = $Apache::inputtags::part.'_'.&Apache::response::start_response($parstack,$safeeval);
   my $xmin=&Apache::lonxml::get_param('xmin',$parstack,$safeeval);
+  $xmin=($xmin?$xmin:-10);
   my $xmax=&Apache::lonxml::get_param('xmax',$parstack,$safeeval);
+  $xmax=($xmax?$xmax:10);
   my $ymin=&Apache::lonxml::get_param('ymin',$parstack,$safeeval);
+  $ymin=($ymin?$ymin:-10);
   my $ymax=&Apache::lonxml::get_param('ymax',$parstack,$safeeval);
-  my $xaxisvisible=&Apache::lonxml::get_param('xaxisvisible',$parstack,$safeeval);
-  my $yaxisvisible=&Apache::lonxml::get_param('yaxisvisible',$parstack,$safeeval);
-  my $gridvisible=&Apache::lonxml::get_param('gridvisible',$parstack,$safeeval);
+  $ymax=($ymax?$ymax:10);
+  my $xaxisvisible=(&Apache::lonxml::get_param('xaxisvisible',$parstack,$safeeval)=~/on|true|1/i?'true':'false');
+  my $yaxisvisible=(&Apache::lonxml::get_param('yaxisvisible',$parstack,$safeeval)=~/on|true|1/i?'true':'false');
+  my $gridvisible=(&Apache::lonxml::get_param('gridvisible',$parstack,$safeeval)=~/on|true|1/i?'true':'false');
 
 
   if ($target eq 'web') {
      $result.=&start_init_script($internalid);
+     $result.=&axes_script($internalid,$xmin,$xmax,$ymin,$ymax,$xaxisvisible,$yaxisvisible,$gridvisible);
   }
   return $result;
 }