Added plugin object to qml context

include/rqt_demo_plugin/lineItem.hpp

@@ -2,6 +2,7 @@
 #include <QtQuick/QQuickItem>
 #include <qchar.h>
 #include <qglobal.h>
+#include <qobject.h>
 #include <qobjectdefs.h>
 #include <qpoint.h>
 #include <qquickitem.h>
@@ -11,7 +12,11 @@ class LineItem : public QQuickItem
 {
     Q_OBJECT
 
-    Q_PROPERTY(QString stupid READ stupid WRITE setStupid)
+    Q_PROPERTY(float scale READ scale WRITE setScale NOTIFY scaleChanged)
+    Q_PROPERTY(QString stupid READ stupid WRITE setStupid NOTIFY stupidChanged)
+    Q_PROPERTY(QObject* handler READ handler WRITE setHandler NOTIFY handlerChanged)
+            
+
     QML_ELEMENT
 public:
     LineItem(QQuickItem *parent = nullptr);
@@ -20,13 +25,21 @@ public:
     QSGNode *updatePaintNode(QSGNode *, UpdatePaintNodeData *) override;
 
     QString stupid() const {return stupid_;}
+    QObject* handler() const {return  handler_;}
+
+    void setStupid(const QString &str) {stupid_ = str;}
+    void setScale(const float scale) {scale_ = scale;}
+    void setHandler(QObject* const obj) {handler_ = obj;}
+
+signals:
+    void stupidChanged(const QString &str);
+    void handlerChanged(QObject* const obj);
 
-    void setStupid(const QString &str) {
-        stupid_ = str;
-        qDebug() << str;
-    }
     
 
 private:
+    float scale_;
     QString stupid_;
+    QObject* handler_;
+    int prev_size=0;
 };

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

log/latest_build

@@ -1 +1 @@
-build_2025-03-09_02-21-28
+build_2025-03-10_12-03-53

resources/qml/helloworld.qml

@@ -1,12 +1,15 @@
 import QtQuick 2.3
 import LineItem 1.0
+import DemoPlugin 1.0
 
 Rectangle {
+    id: rr
     color: "gray"
+    property var scale: 0.4
     Flickable {
         width: parent.width;
         height: parent.height
-        contentWidth: 2500*4; contentHeight: 1500*4
+        contentWidth: 3000*rr.scale; contentHeight: 2000*rr.scale
         flickDeceleration: 10000
         leftMargin: Math.max((width - contentWidth)/2,0)
         topMargin: Math.max((height - contentHeight)/2,0)
@@ -17,36 +20,21 @@ Rectangle {
             id: contentRect
             anchors.top: parent.top
             anchors.left: parent.left
-            width: parent.width/4
+            width: parent.width/rr.scale
-            height: parent.height/4
+            height: parent.height/rr.scale
             
-            transform: Scale {yScale: 4; xScale: 4}
+            transform: Scale {yScale: rr.scale; xScale: rr.scale}
             transformOrigin: Item.TopLeft
 
             Row {
                 x:0
                 y:0
-                spacing: 4
 
-                Rectangle {
-                    height: 100
-                    width: 100
-                    color: "green"
-                    Text {
-                        text: "Hello, World!"
-                    }
-                }
-                Rectangle {
-                    height: 100
-                    width: 100
-                    color: "red"
-                    Text {
-                        text: "Hello, World!"
-                    }
-                }
                 LineItem {
-                    height: 100
+                    height: 2000
-                    width: 100
+                    width: 3000
+                    scale: rr.scale
+                    handler: DemoPlug.demoPlugin
                 }
             }
         }

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)
+    , 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 = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), hello_c);
-        geometry->setLineWidth(5);
+        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();
+    } else {
-        QSizeF s = size();
+        node = static_cast<QSGGeometryNode *>(old);
-        verticies[0].set(0.1 * s.width(), 0.1 * s.height());
+        geometry = node->geometry();
-        verticies[1].set(0.75 * s.width(), 0.75 * s.height());
+        if(hello_c != prev_size) {
-        verticies[2].set(0.1 * s.width(), 0.9 * s.height());
+            geometry->allocate(prev_size);
-        verticies[3].set(0.9 * s.width(), 0.1 * s.height());
-        node->markDirty(QSGNode::DirtyGeometry);
         }
+    }
+
+
+    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;
   }
 }