Re-Open Update START
Since the latest 5.4.1 which includes the first patch for this issue, QQuickWidget won't work anymore at all.

A warning is thrown: "W/Qt (16609): qquickwidget.cpp:96 (void QQuickWidgetPrivate::init(QQmlEngine*)): QQuickWidget is not supported on this platform."

Tested on Galaxy Tab3 (4.2.2) and Nexus5 (5.0.1).

Before, the QQuickWIdget worked, and the sample I posted here worked also as described, aka it has shown the camera view after re-opening once.
Re-Open Update END

I’m trying to implement a QR Code Scanner for Android in a Qt Widget project.

The following code shows how I load the QML code. “camView” is the QQuickWidget. It should display a live stream of the camera video.

Instead it shows nothing but freezes the whole application, until I do minimize it via the Android home button. Once I resume the application from background, it shows the video feed perfectly.

void MainWindow::openScanner()

{ returnToCamview(); QGridLayout *layout = new QGridLayout; layout->addWidget(camView); camView->setSource(QUrl("qrc:/cameraView.qml")); camView->setResizeMode(QQuickWidget::SizeRootObjectToView); ui->camBox->setLayout(layout); camView->show(); }