[SOLVED]Why QGraphicsScene does not add the QGraphicsRect?



  • Hello, and happy tomorrow new year! I have a simple code, I must draw a rect in QGraphicScene but it`s not displayed. Here is the code:
    @
    myScene = new QGraphicsScene;
    myView = new QGraphicsView(myScene);
    myView->setMaximumWidth(width);
    myView->setMaximumHeight(height);
    myScene->setBackgroundBrush(QBrush(Qt::red));
    myScene->setSceneRect(QRectF(0,0,width-(width/40),
    height-(height/40)) );
    screenItem = new ActionRectItem(100, 100, 100, 100,
    "Screen", 1, NULL,
    myScene,
    new Callbacks(dummy3,
    dummy1,
    dummy2,
    doer));

    ((QGraphicsRectItem*)screenItem)->setBrush(QBrush(Qt::green));
    myScene->addItem((QGraphicsRectItem*)screenItem);
    myView->show();
    

    @
    Where ActionRectItem is subclass of QGraphicsRect item. Ive tried with a pure QGraphicsRectItem, its not added aswell.
    [EDIT] Ill add the QGraphicsRectItem is not displayed, not the scene. [EDIT] It appeared that Ive forgot to implement my custom overriden paint() from QGraphicsRectItem:
    @
    void ActionRectItem::paint(QPainter painter, const QStyleOptionGraphicsItem option, QWidget widget)
    {
    functors->onPaint(painter, option, widget, (ActionRectItem
    )this);
    }
    @
    And when I implement:
    @
    static inline void customOnPaint(QPainter
    qp,
    const QStyleOptionGraphicsItem
    qsi,
    QWidget* wd, QGraphicsItem* ari) {

    QBrush Brush(Qt::green);
    ((QGraphicsRectItem*)ari)->setBrush(QBrush(Qt::red));
    ((QGraphicsRectItem*)ari)->setRect(
                ((QGraphicsRectItem*)ari)->boundingRect()
                );
    qp->fillRect(((QGraphicsRectItem*)ari)->boundingRect()
            , Brush);
    

    }
    @

    Its working now, it was my mistake. Sorry.



  • I think there are some wrong size calculations.
    The example below shows green square on red view.
    @
    MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
    {
    ui->setupUi(this);

    QGraphicsScene* myScene = new QGraphicsScene(this);
    QGraphicsView* myView = new QGraphicsView(myScene, ui->centralWidget);
    myView->setScene(myScene);
    int width = this->width();
    int height = this->height();
    myView->setMaximumWidth(width);
    myView->setMaximumHeight(height);
    myScene->setBackgroundBrush(QBrush(Qt::red));
    myScene->setSceneRect(QRectF(0, 0, width, height));
    QGraphicsRectItem* screenItem = new QGraphicsRectItem(100, 100, 100, 100);
    

    // screenItem = new ActionRectItem(100, 100, 100, 100,
    // "Screen", 1, NULL,
    // myScene,
    // new Callbacks(dummy3,
    // dummy1,
    // dummy2,
    // doer));

    ((QGraphicsRectItem*)screenItem)->setBrush(QBrush(Qt::green));
    myScene->addItem((QGraphicsRectItem*)screenItem);
    

    // myView->show();
    }
    @



  • You are right. But why is that... Kind of messy it got here :S



  • OK, so I have QGraphicsItem, with overriden methods, paint, advance and onMousePressEvent. So, how I add the QGraphicsRectItem to be below the invisible QGraphicsItem, who is overriden, or how do I pass these functions to QGraphicsRectItem?



  • Ive solved it :( Appeared to be entirely my mistake, since I was working with it and Ive forgot an important override.


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