--- loncom/homework/functionplotresponse.pm	2010/10/04 20:47:29	1.5
+++ loncom/homework/functionplotresponse.pm	2010/10/05 01:28:00	1.7
@@ -1,7 +1,7 @@
 # LearningOnline Network with CAPA
 # option list style responses
 #
-# $Id: functionplotresponse.pm,v 1.5 2010/10/04 20:47:29 www Exp $
+# $Id: functionplotresponse.pm,v 1.7 2010/10/05 01:28:00 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','backgroundplot'));
+  &Apache::lonxml::register('Apache::functionplotresponse',('functionplotresponse','backgroundplot','spline'));
 }
 
 #
@@ -139,7 +139,27 @@ ENDUPDATESCRIPT
 
 sub update_register {
    my ($id,$variable)=@_;
-   return "document.ggbApplet_$id.registerObjectUpdateListener('$variable','updatePointCoordinates_$id')";
+   return "document.ggbApplet_$id.registerObjectUpdateListener('$variable','updatePointCoordinates_$id');\n";
+}
+
+#
+# Set a coordinate variable
+#
+sub set_coordinate {
+   my ($id,$variable,$x,$y)=@_;
+   return (<<ENDSETVARIABLE);
+coordinateMap_$id\['$variable.x'] = $x;
+coordinateMap_$id\['$variable.y'] = $y;
+document.ggbApplet_$id.evalCommand("$variable=("+coordinateMap_$id\["$variable.x"]+","+coordinateMap_$id\["$variable.y"]+")");
+ENDSETVARIABLE
+}
+
+#
+# Initialize a new coordinate variable at set a listener on it
+#
+sub new_coordinate {
+    my ($id,$variable,$x,$y)=@_;
+    return &set_coordinate($id,$variable,$x,$y).&update_register($id,$variable);
 }
 
 #
@@ -179,28 +199,100 @@ ENDAXESSCRIPT
 }
 
 sub plot_script {
-   my ($id,$function)=@_;
-   return (<<ENDPLOTSCRIPT);
-            document.ggbApplet_$id.evalCommand("y=$function");
+   my ($id,$function,$fixed)=@_;
+   if ($fixed) {
+# Use stupid trick to nail this to a location
+      return (<<ENDPLOTSCRIPT);
+            document.ggbApplet_$id.evalCommand("a=1");
+            document.ggbApplet_$id.setVisible("a",false);
+            // This MUST be a DEPENDENT OBJECT in order to be locked down:
+            document.ggbApplet_$id.evalCommand("y=a*($function)");
 ENDPLOTSCRIPT
+   } else {
+       return "document.ggbApplet_$id.evalCommand('y=$function')";
+   }
 }
 
 #
-# <backgroundplot function="..." />
+# Subroutine that generates code for spline $label based on stored information
+#
+
+sub generate_spline {
+   my ($id,$label)=@_;
+   my $result='';
+   my $order=$Apache::functionplotresponse::splineorder{$label};
+   my $x=$Apache::functionplotresponse::splineinitx{$label};
+   my $y=$Apache::functionplotresponse::splineinity{$label};
+   my $sx=$Apache::functionplotresponse::splinescalex{$label};
+   my $sy=$Apache::functionplotresponse::splinescaley{$label};
+   my @coords=();
+   foreach my $i (1..$order) {
+       $result.=&new_coordinate($id,$label.'P'.$i,$x,$y);
+       $x+=$sx/$order;
+       push(@coords,$label.'P'.$i);
+       $result.=&new_coordinate($id,$label.'S'.$i,$x,$y+$sy);
+       $x+=$sx/$order;
+       push(@coords,$label.'S'.$i);
+   }
+   $result.='document.ggbApplet_'.$id.'.evalCommand("Spline'.$order.'['.join(',',@coords).']");'."\n";
+   return $result;
+}
+#
+# <backgroundplot function="..." fixed="yes/no" />
 #
 sub start_backgroundplot {
    my ($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);
+   my $fixed=(&Apache::lonxml::get_param('fixed',$parstack,$safeeval)=~/on|true|yes|1/i?1:0);
+ 
    unless ($function) { $function="0"; }
    if ($target eq 'web') {
-      $result.=&plot_script($internalid,$function);
+      $result.=&plot_script($internalid,$function,$fixed);
    }
    return $result;
 }
 
 sub end_backgroundplot {
+   return '';
+}
+
+#
+# <spline label="..." order="1,2,3,4" initx="..." inity="..." scalex="..." scaley="..." />
+#
+# Unfortunately, GeoGebra seems to want all splines after everything else, so we need to store them
+#
+sub start_spline {
+   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+   my $label=&Apache::lonxml::get_param('label',$parstack,$safeeval);
+   $Apache::functionplotresponse::counter++;
+   unless ($label) { $label='S'.$Apache::functionplotresponse::counter; }
+
+   my $order=&Apache::lonxml::get_param('order',$parstack,$safeeval);
+   if (($order<2) || ($order>4)) { $order=2; }
+   $Apache::functionplotresponse::splineorder{$label}=$order;
+
+   my $x=&Apache::lonxml::get_param('initx',$parstack,$safeeval);
+   unless ($x) { $x=0; }
+   $Apache::functionplotresponse::splineinitx{$label}=$x;
+
+   my $y=&Apache::lonxml::get_param('inity',$parstack,$safeeval);
+   unless ($y) { $y=0; }
+   $Apache::functionplotresponse::splineinity{$label}=$y;
+
+   my $sx=&Apache::lonxml::get_param('scalex',$parstack,$safeeval);
+   unless ($sx) { $sx=$order; }
+   $Apache::functionplotresponse::splinescalex{$label}=$sx;
+
+   my $sy=&Apache::lonxml::get_param('scaley',$parstack,$safeeval);
+   unless ($sy) { $sy=2; }
+   $Apache::functionplotresponse::splinescaley{$label}=$sy;
+   return '';
+}
+
+sub end_spline {
+   return '';
 }
  
 sub end_init_script {
@@ -214,7 +306,16 @@ ENDENDINIT
 sub start_functionplotresponse {
   my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
   my $result='';
+# To remember the splines - somehow, they need to come last
+  undef %Apache::functionplotresponse::splineorder;
+  undef %Apache::functionplotresponse::splineinitx;
+  undef %Apache::functionplotresponse::splineinity;
+  undef %Apache::functionplotresponse::splinescalex;
+  undef %Apache::functionplotresponse::splinescaley;
+  $Apache::functionplotresponse::counter=0;
+# Internal ID to mark the applet and its coordinates
   my $internalid = $Apache::inputtags::part.'_'.&Apache::response::start_response($parstack,$safeeval);
+# Parameters of <functionplotresponse>
   my $xmin=&Apache::lonxml::get_param('xmin',$parstack,$safeeval);
   $xmin=($xmin?$xmin:-10);
   my $xmax=&Apache::lonxml::get_param('xmax',$parstack,$safeeval);
@@ -223,9 +324,9 @@ sub start_functionplotresponse {
   $ymin=($ymin?$ymin:-10);
   my $ymax=&Apache::lonxml::get_param('ymax',$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');
+  my $xaxisvisible=(&Apache::lonxml::get_param('xaxisvisible',$parstack,$safeeval)=~/on|true|yes|1/i?'true':'false');
+  my $yaxisvisible=(&Apache::lonxml::get_param('yaxisvisible',$parstack,$safeeval)=~/on|true|yes|1/i?'true':'false');
+  my $gridvisible=(&Apache::lonxml::get_param('gridvisible',$parstack,$safeeval)=~/on|true|yes|1/i?'true':'false');
 
   if ($target eq 'web') {
 # paste in the update routine to receive stuff back from the applet
@@ -248,6 +349,10 @@ sub end_functionplotresponse {
 
 #  if ($target eq 'edit') { $result=&Apache::edit::end_table(); }
   if ($target eq 'web') {
+# Now is the time to render all of the stored splines
+     foreach my $label (keys(%Apache::functionplotresponse::splineorder)) {
+        $result.=&generate_spline($internalid,$label);
+     }
 # close the init script
      $result.=&end_init_script();
 # actually start the <applet>-tag