Qt - Making a panel that overlaps a QGraphicsView

Question

I am trying to make a panel that shows some data, that gets added when I press a button. I will explain it trough these images:

this would be the initial state of the app, a window with a QGraphicsView

if I click "Help" it should display a window above it that never goes out of focus

I looked into using QDockWidget, but that just creates a panel next to it, that that's not what I Want. If anyone knows how to do this, I would be very grateful, thanks.

Answer 1

You can set children widgets in your QGraphicsView and consider it like a regular QWidget:

    QApplication app(argc, argv);
    QGraphicsScene* scene = new QGraphicsScene(0, 0, 1000, 1000);
    QGraphicsView* view = new QGraphicsView(scene);
    view->show();

    QPushButton* button = new QPushButton("Show label");
    QLabel* label = new QLabel("Foobar");
    QVBoxLayout* layout = new QVBoxLayout(view);
    layout->setAlignment(Qt::AlignRight | Qt::AlignTop);
    layout->addWidget(button);
    layout->addWidget(label);
    label->hide();
    QObject::connect(button, &QPushButton::clicked, label, &QLabel::show);
    return app.exec();

The label will be visible in the QGraphicsView when you click on the button.

You can also embed a widget in your scene with QGraphicsProxyWidget class:

    QApplication app(argc, argv);
    QGraphicsScene* scene = new QGraphicsScene(0, 0, 1000, 1000);
    scene->addItem(new QGraphicsRectItem(500, 500, 50, 50));
    QGraphicsView* view = new QGraphicsView(scene);
    view->show();

    QWidget* w = new QWidget();
    QGraphicsProxyWidget* proxy = new QGraphicsProxyWidget();


    QPushButton* button = new QPushButton("Show label");
    QLabel* label = new QLabel("Foobar");
    QVBoxLayout* layout = new QVBoxLayout(w);
    layout->addWidget(button);
    layout->addWidget(label);
    layout->setAlignment(Qt::AlignRight | Qt::AlignTop);
    label->hide();
    QObject::connect(button, &QPushButton::clicked, label, &QLabel::show);

    proxy->setWidget(w);
    scene->addItem(proxy);
    return app.exec();