How to capture an QML child element to an png?

[VTiTux]

Hi,
I see this "method: ":http://stackoverflow.com/questions/11011391/saving-qml-image
but it doesn't work.
I substitue QDeclarativeItem by QQuickItem:
@
void Capturer::save(QQuickItem *item)
{
QPixmap pix(item->width(), item->height());
QPainter painter(&pix);
QStyleOptionGraphicsItem option;
item->paint(&painter, &option, NULL);
pix.save("/path/to/output.png");
}
@

but QQuickItem hasn't got an 'paint' method.
So, I use the QQuickPaintedItem class:

@
void Capturer::save(QQuickItem *item)
{
QPixmap pix(item->width(), item->height());
QPainter painter(&pix);
QQuickPaintedItem paintedItem(item);
paintedItem.paint(&painter);
pix.save("/path/to/output.png");
}@

but the error is "cannot declare variable 'paintedItem' to be of abstract type 'QQuickPaintedItem'"

How can I to do an capture of my QML element (not the whole scene, but of an sub-element)?

Thanks.

[VTiTux]

I also try this "method.":http://qt-project.org/forums/viewthread/3948
Don't work. Item is null.
I try with QML Rectangle and QML Image as imageObj.

[Vincent007]

You need to wait for Qt 5.3

[VTiTux]

I have an another problem.

With this code:
@
void SessionManager::test(){
QQmlComponent component(pEngine, QUrl::fromLocalFile( "..../Test.qml" ));
QObject *object = component.create();
QQuickItem item = qobject_cast<QQuickItem>(object);
QQuickItem scene = pRootObject->findChild<QQuickItem>("Window1");
item->setParentItem(scene);
QQuickWindow *window = item->window();
QImage image = window->grabWindow();
image.save( "..../test1.jpg" );
}
@

• If I run this function in my main(), before "app.exec()", my view is painted but test1.jpg isn't created.

• If I launch this function with a mouse control and a signal/slot (I use a notification icon menu to launch my development functions), (so, this function is executed later than the main() initialisation), my view is empty, but I have the jpeg file.

My root object isn't a visible item.
My main.qml looks like this:
@
Item{
Window{
Item{ objectName: "Window1" }
}
Window{
Item{ objectName: "Window2" }
}
Window{
Item{ objectName: "Window3" }
}
}

@

So, my "Test.qml" item isn't visible when it is created. But it is showed after the affectation 'setParentItem()'. (except with this problem...)
If I remove the capture, all works fine.
If I move my item to the window2 after the capture, it is visible:

@
void SessionManager::test(){
QQmlComponent component(pEngine, QUrl::fromLocalFile( "..../Test.qml" ));
QObject *object = component.create();
QQuickItem item = qobject_cast<QQuickItem>(object);
QQuickItem scene = pRootObject->findChild<QQuickItem>("Window1");
item->setParentItem(scene);
QQuickWindow *window = item->window();
QImage image = window->grabWindow();
image.save( "..../test1.jpg" );
QQuickItem scene2 = pRootObject->findChild<QQuickItem>("Window2");
item->setParentItem(scene2);
}
@
But without that, that doesn't work.

It is a bug with QtQuick? Or what?

[Tân Ngọc Đỗ]

Hello,

Have you found the solution for this issue ?

[mehrdad]

it is my problem too...

[David Stiel]

Check out "this":http://doc.qt.io/qt-5/qml-qtquick-item.html#grabToImage-method. I think it solves your problem

[David Stiel]

Check out "this":http://doc.qt.io/qt-5/qml-qtquick-item.html#grabToImage-method. I think it solves your problem

[Tân Ngọc Đỗ]

Yes, The solution has just appeared in Qt 5.4

[Tân Ngọc Đỗ]

Yes, The solution has just appeared in Qt 5.4

[mehrdad]

and how?

[mehrdad]

and how?

[JKSH]

[quote author="mehrdad" date="1423500644"]and how?[/quote]Did you read David Stiel's link?

[JKSH]

[quote author="mehrdad" date="1423500644"]and how?[/quote]Did you read David Stiel's link?