Button over QVideoWidget

[Bonty]

Hi @jsulm,

I am creating an application based on usb camera and I want some buttons overlay on video streaming from camera.

[Bonty]

Hi @jsulm ,

In Qt5.15.2 it is simply drag button over video widget and its working but its not the same in Qt6. So I don't think Qt5 and Qt6 is similar, even there is changes in Qt5.13 and Qt5.15 also.

Please help !!

[jsulm]

@Bonty said in Button over QVideoWidget:

but its not the same in Qt6

What does this mean exactly? What happens in Qt6?

[Bonty]

In QT6 the button hide behind video.

[arsinte_andrei]

@Bonty look at the button properties..and bring it to front

[Bonty]

@arsinte_andrei

Still not working, hide behind video.

[JoeCFD]

@Bonty can you try to create the button with the parent of videoWidget?

QPushButton *button = new QPushButton(videoWidget->parentWidget() );

then move it to the right position

[Bonty]

Hi @JoeCFD

Thanks for replying!

Here is my code and application output image but still same issue:-

#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    m_camera.reset(new QCamera(QMediaDevices::defaultVideoInput()));
    m_captureSession.setCamera(m_camera.data());
    m_captureSession.setVideoOutput(ui->videoWidget);
    m_camera->start();
    QPushButton *button = new QPushButton(ui->videoWidget->parentWidget() );
    button->setGeometry(100,100,100,100);
 }



MainWindow::~MainWindow()
{
    delete ui;
}

[JoeCFD]

Try the following as well and add some background color(like green for testing)
button->setWindowFlags((Qt::WindowFlags)(Qt::WindowStaysOnTopHint ) );

[SGaist]

Hi,

In Qt 6, the QVideoWidget uses a QWindow based class to do the rendering which means OpenGL is used for the rendering and it's likely a top level surface hence your buttons that renders behind it.
You might want to consider making use of QML for that part.

[Bonty]

Hi @SGaist,

Thanks for suggestion! Its working using QML. But there is problem in QML is that I cant change camera input format and frame rate. If possible then how I can change?

Please help!!

[SGaist]

@Bonty How is your QtQuick code looking currently ?

[xylo212]

This post is deleted!

[QtFriend2024]

Hello, I have the same problem.

QT 6.7.3

QT Creator: 15.*
Target O.S.: Windows 11

I want QPushButton(s) [and QLabel(s)] to display in front of my QVideoWidget object, but the QVideoWidget object keeps getting forced to the front, so all other QObjects get hidden behind the QVideoWidget object. My QVideoWidget displays within a window (not within a QDialog).

• I've tried QWidget::lower() / QWidget::raise() on the QVideoWiget and QPushButton but the QVideoWidget still gets forced to the front.

• I've tried setting the parent of the QPushButton to the QVideoWidget object but am still not able to force the QPushButton to display in front of the QWidget object.

• I've tried adding the QVideoWidget and QPushButton to a QVBoxLayout then used move() and raise() to move the QPushButton to the front of the QVideoWidget object but the QVideoWidget remains forced to the front.

Note: I AM able to get a QDialog to display in front of the QVideoWidget but this is not what I want.

How can I get a QPushButton to display in front of the QVideoWidget?

Thanks!

[jsulm]

@QtFriend2024 Please read what @SGaist wrote. It will not work with widgets, but should work with QML.

[QtFriend2024]

@jsulm Ok thank you. I was trying to avoid using QML, but I will try this.

[QtFriend2024]

For QWidget Applications, will this ever be resolved - being able to stack QPushButton in front of a QVideoWidget, or must we always resort to QML and QTQuick applications? My application was already built as a Widget application. This is frustrating. I've spent many hours getting this to work. For my widget application, I have to throw in a dummy QQuickWidget in the stack (1px x 1px) just to get QT 6.7.3 to stack the QVideoWidget correctly inconsistently.

[QtFriend2024]

@jsulm I need this problem solved without QML.

[SGaist]

@QtFriend2024 You mention that you managed to make it work with that workaround. Can you provide a minimal compilable example that shows it in action ?

[QtFriend2024]

One Solution Without QML

I've figured a way to get the QVideoWidget to stack behind QPushButton and QLabel in a Widgets application without using QML - the camera has to be started before the stacking order is set. Otherwise, the QVideoWidget gets forced to the front no matter what you do. This worked for me.