Extract QImage from QQuickItem

Hi,

I would like to process an image loaded into a Flickable QML element in C++ land but I am failing to obtain the original image. So far I'm only seem able to obtain an image of the QQuickWindow
and would liek to know if there is a way to obtain the whole loaded image.

I am calling a Q_INVOKABLE method of a C++ object as follows:

Code:

---

Flickable {
        id: content
        clip: false
        anchors.fill: parent
        boundsBehavior: Flickable.StopAtBounds
 
        Loader {
            id: contentLoader
            anchors.centerIn: parent
        }
 
        MouseArea {
            anchors.fill: parent
            onClicked: {
                console.log("[veo] onClicked - capture triggered")
                cplusplusobject.process(contentLoader.item)                 <----------------- call to C++
            }
        }

---

In C++ I have:

Code:

---

void
Cplusplusobject::process(const QVariant &v)
{
    qDebug() << "[veo]" << __FUNCTION__;
    QQuickItem *item = qobject_cast<QQuickItem *>( v.value<QObject*>() );
    qDebug() << "Item dimensions:" << item->width() << item->height();
 
    item->dumpObjectInfo();
 
    QQuickWindow *window = item->window();
    QImage image = window->grabWindow();
...

---

The printed item dimensions do correspond to the original image but I fail to see how to turn the QQuickItem into a QImage.

Any suggestions please?

Up
I'm also interested by an answer.

I would like to store an child QML item to an image.
Currently, I use the grabWindow() method. It works, but this isn't what I want. This stores the whole window.

I saw this method, which looks right:
http://stackoverflow.com/questions/1...ving-qml-image
But QtDeclarativeItem is obsolete, and QQuickItem hasn't got a Paint() method.
I tried to use the QQuickPaintedItem class, which has got a paint() method, but it is virtual. I don't know how to use it in my case (I'm a newbie).

I am also interested in that. Does anyone get it?

In Qt Quick items are OpenGL primitives. If you want to get them as images, you have to force the item to be rendered on a texture, e.g. using ShaderEffectSource and then use QQuickItem API to identify the texture so that you can download it from the atlas. That is not something straightforward though.

If the item is fully visible, you could grab a screenshot of the window (QWindow::grabWindow()) and the copy the area of the item into the target image.

Cheers,
_