Allow passing arguments to windows.

The script functions createWindow() and createReport() now allow an
optional 2nd argument. This can be any script value and it will be
available as the arguments property on the newly created window.

src/typica.w

 QScriptValue createWindow(QScriptContext *context, QScriptEngine *engine)@/
 {
     QString targetID = argument<QString>(0, context);
+    @<Get window arguments@>@;
     QDomNode element;
     QScriptValue object;
     @<Find the window element@>@;
 QScriptValue createReport(QScriptContext *context, QScriptEngine *engine)
 {
     QString targetID = argument<QString>(0, context);
+    @<Get window arguments@>@;
     QFile file(QString("reports:%1").arg(targetID));
     QScriptValue object;
     if(file.open(QIODevice::ReadOnly))
     return object;
 }
 
+@ Sometimes it is useful to pass information to a window when it is created.
+A 2nd optional argument to window creation functions can be any script value
+which will be made available under the {\tt arguments} property of the newly
+created window.
+
+@<Get window arguments@>=
+QScriptValue arguments;
+if(context->argumentCount() > 1)
+{
+    arguments = context->argument(1);
+}
+
 @ First we must locate the {\tt <window>} element. The most sensible way to do
 this would require that each {\tt <window>} element has an ID attribute and
 search the DOM tree for that ID. Unfortunately, as of this writing,
 window->setObjectName(targetID);
 object = engine->newQObject(window);
 setQMainWindowProperties(object, engine);
+object.setProperty("arguments", arguments);
 QWidget *central = new(QWidget);
 central->setParent(window);
 central->setObjectName("centralWidget");
         QScriptContext *context = engine->pushContext();
         QScriptValue object;
         QString targetID = reportFile;
+        QScriptValue arguments;
         @<Display the window@>@;
         file.close();
         engine->popContext();