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?