Displaying Multiple QLabels in QGraphicsScene

TrofikdofiK

I have a class A that inherits QLable.

class_A.h

class A : public QLabel
{
    Q_OBJECT;

public:
    A(const A& element);
    ~A() = default;

    void setPos();
protected:
    short x, y;
};

class_A.cpp

A::A(ElementType type)
: QLabel(), type(type), dir(Stop)
{
    setFixedSize(20, 20);
    x = pos().x();
    y = pos().y();
};
A::A(const A& element)
{
    setFixedSize(20, 20);
    this->x = element.x;
    this->y = element.y;
}

void A::setPos()
{
    x = pos().x();
    y = pos().y();
}

And then there's class B, which inherits QGraphicsScene. And one of the parameters is a class A vector.

class_B.h

class B : public QGraphicsScene
{
public:
    B(const char* puth, ushort h, ushort w);
   ~B() = default;
private:
    std::vector<A> otherElement;
};

class_B.cpp

B::B(const char* puth)
: QGraphicsScene()
{
    for (int i = 0; i < 10; ++i)
    {
        otherElement.emplace_back(GameElement::tWall);
        otherElement[i].move(0, i * 20);
        otherElement[i].setPos();
        otherElement[i].setPixmap(QPixmap("../Texture/wall.png"));
        addWidget(&otherElement[i]);
    }
};

And main.cpp

int main(int argc, char* argv[])
{
    QApplication app(argc, argv);
    QGraphicsView view;
    B* scene = new B(puth);
    view.setScene(scene);
    view.show();
    return app.exec();
}

I expect something to be randering on the screen.

And in fact, randering

And if you change the class_B.cpp as follows

B::B(const char* puth)
: QGraphicsScene()
{
    for (int i = 0; i < 10; ++i)
    {
        otherElement.emplace_back(GameElement::tWall);
        otherElement[i].move(0, i * 20);
        otherElement[i].setPos();
        otherElement[i].setPixmap(QPixmap("../Texture/wall.png"));
        addWidget(&otherElement[i]);
    }
    otherElement.pop_back();
};

Then we will stop withdrawing anything at all.

Why this happens and how to add a few QLables to QGraphicsScene through a loop

SGaist

Hi and welcome to devnet,

Pardon my bluntness but why that convoluted architecture when the graphics view framework already has classes to show images as well as text ? Adding QLabels for that is rather a waste of ressources.

Check the QGraphicsPixmapItem and QGraphicsTextItem.

TrofikdofiK

@SGaist said in Displaying Multiple QLabels in QGraphicsScene:

ng QLabels for that is rather a waste of ressources.
Check the QGraphicsPixmapItem and QGraphicsTextItem.

The fact is that A is a class from which the classes that display gif animation are also inherited. And in QGraphicsPixmapItem I tested the animation does not go

SGaist

Then please check this forum post. It shows how to implement a custom item that will handle your animated gif.