Added plugin object to qml context

src/lineItem.cpp

@@ -1,4 +1,7 @@
 #include "rqt_demo_plugin/lineItem.hpp"
+#include "rqt_demo_plugin/rqt_demo_plugin.hpp"
+#include <qglobal.h>
+#include <qqmlerror.h>
 #include <qquickitem.h>
 #include <qsgflatcolormaterial.h>
 #include <qsggeometry.h>
@@ -7,7 +10,9 @@
 
 LineItem::LineItem(QQuickItem *parent) 
     : QQuickItem(parent)
-    , stupid_("") 
+    , scale_(1) 
+    , stupid_("")
+    , handler_(nullptr)
 {
     setFlag(ItemHasContents, true);
 }
@@ -19,12 +24,21 @@ QSGNode *LineItem::updatePaintNode(QSGNode *old, UpdatePaintNodeData *)
 {
     QSGGeometryNode *node = nullptr;
     QSGGeometry *geometry = nullptr;
+    mg::DemoPluginMg *plugin = static_cast<mg::DemoPluginMg *>(handler_);
+    if(!plugin) {
+        qmlEngine(this)->throwError("Handler plugin was not provided");
+        return old;
+    }
+
+    const int hello_c = plugin->hello_c; 
 
     if(!old) {
         node = new QSGGeometryNode;
-        geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 4);
-        geometry->setLineWidth(5);
+        geometry = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), hello_c);
+        geometry->setLineWidth(3*scale_);
         geometry->setDrawingMode(QSGGeometry::DrawLines);
+        geometry->setVertexDataPattern(QSGGeometry::DynamicPattern);
+        geometry->setIndexDataPattern(QSGGeometry::DynamicPattern);
         node->setGeometry(geometry);
         node->setFlag(QSGNode::OwnsGeometry);
         auto *material = new QSGFlatColorMaterial;
@@ -32,13 +46,26 @@ QSGNode *LineItem::updatePaintNode(QSGNode *old, UpdatePaintNodeData *)
         node->setMaterial(material);
         node->setFlag(QSGNode::OwnsMaterial);
 
-        QSGGeometry::Point2D *verticies = geometry->vertexDataAsPoint2D();
-        QSizeF s = size();
-        verticies[0].set(0.1 * s.width(), 0.1 * s.height());
-        verticies[1].set(0.75 * s.width(), 0.75 * s.height());
-        verticies[2].set(0.1 * s.width(), 0.9 * s.height());
-        verticies[3].set(0.9 * s.width(), 0.1 * s.height());
-        node->markDirty(QSGNode::DirtyGeometry);
+    } else {
+        node = static_cast<QSGGeometryNode *>(old);
+        geometry = node->geometry();
+        if(hello_c != prev_size) {
+            geometry->allocate(prev_size);
+        }
     }
+
+
+    if(hello_c != prev_size) {
+        const QSizeF s = size();
+        QSGGeometry::Point2D *verticies = geometry->vertexDataAsPoint2D();
+        for(int i = 0; i<hello_c; i++) {
+            verticies[i].x = plugin->hello[i].x * s.width();
+            verticies[i].y = plugin->hello[i].y * s.height();
+        }
+        geometry->markVertexDataDirty();
+        node->markDirty(QSGNode::DirtyGeometry);
+        prev_size = hello_c;
+    }
+        
     return  node;
 }

src/rqt_demo_plugin.cpp

@@ -3,6 +3,7 @@
 
 #include "pluginlib/class_list_macros.hpp"
 #include <qnamespace.h>
+#include <qqml.h>
 #include <qsurfaceformat.h>
 PLUGINLIB_EXPORT_CLASS(mg::DemoPluginMg, rqt_gui_cpp::Plugin)
 
@@ -14,6 +15,7 @@ mg::DemoPluginMg::DemoPluginMg() : Plugin() {
   static bool typesRegistered = 0;
   if(!typesRegistered) {
     qmlRegisterType<LineItem>("LineItem", 1, 0, "LineItem");
+    qmlRegisterAnonymousType<DemoPluginMg>("DemoPlugin", 1);
     typesRegistered = 1;
   }
 }