[Solved] Saving QML image from c++

haris123

I am trying to display network image using qml and then save this image using c++ code,

Here is the qml code,

import QtQuick 2.3
import QtQuick.Window 2.2
import com.login 1.0
Window {
    visible: true
    width : 500
    height: 500

     Login{id: login}

    MouseArea {
        anchors.fill: parent
        onClicked: {
          //  Qt.quit();
            login.save(image);
        }
    }



    Image {
        id: image
        source: "http://www.test.com/webp/gallery/4.jpg"
    }

      
}

And inside my login class saving image like,

void Login::save( QQuickItem *item)
{
    qDebug()<<"width: "<<item->width();
    qDebug()<<"height: "<<item->height();

    QQuickWindow *window = item->window();
    QImage image = window->grabWindow();

    QPixmap pix = QPixmap::fromImage(image);
    pix.save("C:/Users/haris/Desktop/output.png");
}

I am getting the correct width and height of the image inside c++ class, but the problem is I cannot find a way to save the image item from QQuickItem.

Right now I am saving the image by grabing the window, which actually not giving the actual image size on output file, instead giving output file with current qml window size.

Basically I am following the code here http://stackoverflow.com/questions/11011391/saving-qml-image but it seems QDeclarativeItem is deprecated in Qt5, so I choose QQuickItem where as there is no paint option in QQuickItem.

p3c0

Hi @haris123 ,
Instead you can use grabToImage and send this data back to C++.
For eg.:

//QML 
Image {
    id: img
    source: "http://www.test.com/webp/gallery/4.jpg"
}

img.grabToImage(function(result) {
    obj.getImage(result.image); //obj = class set as context property
});

getImage returns a QImage which can be passed to C++ for further processing.

//C++
void MyObject::getImage(QVariant var)
{
    QImage img = qvariant_cast<QImage>(var);
    img.save("yay.png");
}

haris123

Thanks,
I have solved it by doing the same from c++ side based on the answer here http://stackoverflow.com/questions/37439554/save-qml-image-inside-c/37439848#37439848