Added plugin object to qml context

include/rqt_demo_plugin/rqt_demo_plugin.hpp

@@ -6,11 +6,13 @@
 #include <QtQuick>
 #include <QtWidgets>
 #include <qfileinfo.h>
+#include <qobject.h>
 #include <qobjectdefs.h>
 #include <qpushbutton.h>
 #include <qquickview.h>
 #include <qquickwindow.h>
 #include <qresource.h>
+#include <qsggeometry.h>
 #include <qurl.h>
 #include <qwidget.h>
 
@@ -21,21 +23,48 @@ namespace mg {
 
 class DemoPluginMg : public rqt_gui_cpp::Plugin {
   Q_OBJECT
+  Q_PROPERTY(QObject* demoPlugin READ demoPlugin NOTIFY demoPluginChanged)  
 public:
   DemoPluginMg();
 
   virtual void shutdownPlugin() {
     cleanupResources();
   }
+
   virtual void initPlugin(qt_gui_cpp::PluginContext &);
+
+  QObject * demoPlugin() const {
+    return (QObject *)(this);
+  }
+
+  const QSGGeometry::Point2D hello[8] = {
+    {0.2,0.2}, {0.8,0.2},
+    {0.2,0.2}, {0.2,0.8},
+    {0.2,0.4}, {0.4,0.8},
+    {0.2,0.4}, {0.1,0.1},
+  };
+
+  const int hello_c = 8;
+
+signals:
+
+  void demoPluginChanged(QObject * const);
+
 };
 
 inline void DemoPluginMg::initPlugin(qt_gui_cpp::PluginContext &pc) {
   initResources();
-  QQuickView *qv = new QQuickView(QUrl("qrc:/qml/helloworld.qml"));
+  const QUrl qrl("qrc:/qml/helloworld.qml");
+  QQuickView *qv = new QQuickView();
+  qv->rootContext()->setContextProperty("DemoPlug", this);
+  qv->setSource(qrl);
   qv->setResizeMode(QQuickView::ResizeMode::SizeRootObjectToView);
+  QSurfaceFormat format = qv->format();
+  format.setSamples(4);
+  qv->setFormat(format);
   QWidget *qw_ = QWidget::createWindowContainer(qv);
   pc.addWidget(qw_);
 }
 
+
 }; // namespace mg