Fix crash in dtor of QGVPage

src/Mod/TechDraw/Gui/MDIViewPage.cpp

@@ -90,10 +90,12 @@ using namespace TechDrawGui;
 
 MDIViewPage::MDIViewPage(ViewProviderPage *pageVp, Gui::Document* doc, QWidget* parent)
   : Gui::MDIView(doc, parent),
-    m_view(new QGVPage(pageVp)),
+    //m_view(new QGVPage(pageVp)),
     pageGui(pageVp),
     m_frameState(true)
 {
+    m_view = new QGVPage(pageVp,m_scene);
+
     m_backgroundAction = new QAction(tr("&Background"), this);
     m_backgroundAction->setEnabled(false);
     m_backgroundAction->setCheckable(true);
@@ -141,7 +143,7 @@ MDIViewPage::MDIViewPage(ViewProviderPage *pageVp, Gui::Document* doc, QWidget*
             this, SLOT(setRenderer(QAction *)));
 
     setWindowTitle(tr("dummy[*]"));      //Yuck. prevents "QWidget::setWindowModified: The window title does not contain a '[*]' placeholder"
-    setCentralWidget(m_view);
+    setCentralWidget(m_view);            //this makes m_view a Qt child of MDIViewPage
 
     m_orientation = QPrinter::Landscape;
     m_pageSize = QPrinter::A4;
@@ -194,7 +196,8 @@ MDIViewPage::~MDIViewPage()
     }
     deleteItems.clear();
 
-    delete m_view;
+    //m_view will be deleted by MDIViewPage as a Qt child
+    //delete m_view;
 }
 
 

src/Mod/TechDraw/Gui/MDIViewPage.h

@@ -28,6 +28,7 @@
 #include "Gui/Selection.h"
 
 #include <QPrinter>
+#include <QGraphicsScene>
 
 QT_BEGIN_NAMESPACE
 class QAction;
@@ -79,6 +80,8 @@ public:
 
     QGVPage* getQGVPage(void) {return m_view;};
 
+    QGraphicsScene m_scene;
+
 public Q_SLOTS:
     void setRenderer(QAction *action);
     void viewAll();

src/Mod/TechDraw/Gui/QGVPage.cpp

@@ -28,7 +28,7 @@
 # include <QFileInfo>
 # include <QFileDialog>
 # include <QGLWidget>
-# include <QGraphicsScene>
+//# include <QGraphicsScene>
 # include <QGraphicsEffect>
 # include <QMouseEvent>
 # include <QPainter>
@@ -77,7 +77,7 @@
 
 using namespace TechDrawGui;
 
-QGVPage::QGVPage(ViewProviderPage *vp, QWidget *parent)
+QGVPage::QGVPage(ViewProviderPage *vp, QGraphicsScene& s, QWidget *parent)
     : QGraphicsView(parent)
     , pageTemplate(0)
     , m_renderer(Native)
@@ -91,7 +91,7 @@ QGVPage::QGVPage(ViewProviderPage *vp, QWidget *parent)
     const char* name = vp->getPageObject()->getNameInDocument();
     setObjectName(QString::fromLocal8Bit(name));
 
-    setScene(new QGraphicsScene(this));
+    setScene(&s);
     //setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
     setCacheMode(QGraphicsView::CacheBackground);
     setTransformationAnchor(AnchorUnderMouse);
@@ -105,12 +105,6 @@ QGVPage::QGVPage(ViewProviderPage *vp, QWidget *parent)
     m_backgroundItem->setZValue(ZVALUE::BACKGROUND);
 //     scene()->addItem(m_backgroundItem); // TODO IF SEGFAULTS WITH DRAW ENABLE THIS (REDRAWS ARE SLOWER :s)
 
-    // Prepare background check-board pattern
-    QLinearGradient gradient;
-    gradient.setStart(0, 0);
-    gradient.setFinalStop(0, height());
-    gradient.setColorAt(0., QColor(72, 72, 72));
-    gradient.setColorAt(1., QColor(150, 150, 150));
     bkgBrush = new QBrush(QColor::fromRgb(70,70,70));
 
     resetCachedContent();

src/Mod/TechDraw/Gui/QGVPage.h

@@ -24,6 +24,7 @@
 #define DRAWINGGUI_CANVASVIEW_H
 
 #include <QGraphicsView>
+#include <QGraphicsScene>
 
 #include "ViewProviderPage.h"
 
@@ -54,7 +55,7 @@ class TechDrawGuiExport QGVPage : public QGraphicsView
 public:
     enum RendererType { Native, OpenGL, Image };
 
-    QGVPage(ViewProviderPage *vp, QWidget *parent = 0);
+    QGVPage(ViewProviderPage *vp, QGraphicsScene& s, QWidget *parent = 0);
     ~QGVPage();
 
     void setRenderer(RendererType type = Native);
@@ -116,7 +117,7 @@ private:
     bool drawBkg;
     QGraphicsRectItem *m_backgroundItem;
     QGraphicsRectItem *m_outlineItem;
-    QBrush *bkgBrush;
+    QBrush* bkgBrush;
     QImage m_image;
     ViewProviderPage *pageGui;
 };