Qt - Making a panel that overlaps a QGraphicsView - c++

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();